TEN-TEC 150-A/B 100W 8 Channel SSb Transceiver User Manual

150-A/B 100W 8 Channel SSb Transceiver
User Manual
OPERATING AND
MAINTENANCE MANUAL

150-A/B 100W 8 Channel SSb Transceiver

GENERAL INFORMATION

UNPACK ING
Carefully remove the Model 150 from the packing carton and examine it for signs of shipping dam- age.
Should any be apparent, notify the deliver- ing carrier immediately, stating the full extent of the damage.
Retain all damaged cartons.
Li-ability for damage rests with the carrier. It is recommended that you keep the shipping car- ton and fillers.
In the event that storage, mov- ing or reshipment becomes necessary, they come in handy. Accessory hardware, etc. are packed with the transceiver.
Make sure that you have not overlooked anything.

DESCRIPTION

The TEN-TEC Medel 150 Transceiver is a medium power single sideband hf transceiver employing the latest techniques in solid state technology.
Two basic models provide up to eight crystal control- led channels, with 100 watts PEP output, between 2 and 12 MHz. The basic 13 volt dc circuit is ideal for portable or  mobile operation and as a base station with optional power canverter. Broadband circuits reduce operator transmitter and receiver adjustments to a minimum.
Model 150-4 provides full coverage between @ and le MHz in four bands: @ to 3, 3 to 5, 5 toe & and 8 to 12 MHz. Any channel may be operated on any frequency within the range without alteration or additional components. A simply constructed pro- gramming cable determines the channel/band config- uration. Model 150-B is a single band transceiver providing all eight channels within any one band. Both models can be supplied with either upper or lower sideband operation, or with both as an op- tion. Also, they are available with eight single frequency simplex channels (standard) or with any combination of single oar two frequency simplex (semi-duplex) channels, employing up to eight total crystals, at additional cost. an effective noise blanker and VOX/CW operation are available as options. Because of the low voltage solid with its carresponding low operating Model 150 will provide you with a very means of communication at its top state design, temperature, dependable performance level for years to come.

SPECIFICATIONS

GENERAL
FREQUENCY RANGE: 2 to 12 MHz. Four bands; o-3, 3-5, 5-8 and 8-12 MHz. CHANNELS: Up to 8 single frequency simplex or 4 two frequency simplex. All crystal  controlled.
OPERATING MODE: A3BJ emission. Upper or lower side- band standard. USB and LSB optional. CW option. FREQUENCY TOLERANCE: +/-100 Hz. Internal  adjust- ment to calibrate all charmels.
TEMPERATURE RANGE: O to 40 degrees C, operating, -20 to 55 degrees storage.
TUNER CONTROL: Channel Selector control selec- tively connects one of eight pins to a common pin to operate preset tuners or linear amp-lifiers. BAND PROGRAMMING: Two shorting connectors can be field modified to change the channel/band plan. POWER REQUIREMENTS: 12 to 14 V dc, 18 A maximum, negative ground. Built-in over-current circuit breaker. CONSTRUCTION: Case and chassis all metal. Modular PC boards except power amplifier. SIZE: HWD 5″x11-3/8″x12-1/8″. (12.7×28.9×30.8 cm). Bail not extended. WEIGHT: 10 lbs. (4.5 kg).

RECEIVER
SENSITIVITY: 0.3 uV for 10 dB S+N/N, maximum. SELECTIVITY: 2. 4 kHz bandwidth @ 6 de, 6. 0 kHz @ 60 dB. Six pole filter at 12.7 MHz. CLARIFIER: +/-100 Hz, typical, receive only. DYNAMIC RANGE: 95 dB, typical. I-F REJECTION: Greater than 60 dB. SQUELCH THRESHOLD: Down to 1 uV input. METER: Automatic switching. Reads “S” Units to 30 dB over S9. 59=50 uV. AUDIO OUTPUT: 4 watts @ ohms, 300-3000 Hz.

TRANSMITTER
MAXIMUM POWER INPUT: 200 watts. POWER OUTPUT: 90-100 watts @ 13.5 V dc. TUNE POWER: Approximately 25 watts of carrier gen-erated when CARRIER push-button is depressed for antenna tuneup and frequency adjustments. DUTY CYCLE: 100% SSB; 100% RTTY with external cooling fan directed at heatsink. RF OUTPUT IMPEDANCE: 50 ohms, unbalai-t,, SIDEBAND GENERATION: Balanced modulator through 6 pole filter. SWITCHING MODE: Push-To-Talk (PTT) switch on micro- phone. VOX optional. CARRIER SUPPRESSION: 50 dB minimum. UNWANTED SIDEBAND: 40 dB, minimum @ 1 kHz. SPURIOUS AND HARMONIC RESPONSES: Greater than 40 dB below full power rating. AUTOMATIC LEVEL CONTROL: Internal threshold ad-justment. LED indicator. MODULATION: Speech compression circuits automati-cally maintain optimum modulation level. Inter-nal presets for degree of compression and mic- rophone sensitivity. METER: Automatically switches when transmitting. Reads Standing Wave Ratio (SWR) calibrated to TUNE power reference. VOX/CW OPTION: Three internal controls for level, delay and anti-vox. CW offset of 800 Hz. MICROPHONE INPUT: Low impedance types with 5 mis., level, minimum. Polarizing voltage for Model 700-C Electret Microphone (supplied) available at connector. Standard four terminal locking type connector.

FRONT PANEL CONTROLS AND CONNECTIONS
CHANNEL SELECTOR switch: VOLUME control: POWER ON/ OFF switch: SQUELCH/OFF control and pull switch: CLARIFIER control: USB/LSB switch: PTT/VOX-CW switch: NB (Noise Blanker) switch: MIC connector: PHONES jack.

REAR PANEL CONNECTORS
POWER socket: CARRIER switch: PATCH-IN and OUT Jacks: AUX 12 VDC jack: T/R control jack: CHANNEL SWITCH connector.
INDICATORS
Illuminated panel meter (signal strength and SWR): Modulation Light Emitting Diode (LED).

SECTION II INSTATION

NOTICE: Sections II and TII (INSTALLATION and OPERATION) of this manual assume that all desired operating crystals and options are instalied in the transceiver. If  this is not the case, refer to Section IV, INSTALLING CRYSTALS AND OPTIONS, before proceeding with this section,

GENERAL.
For fixed station installations, choose an opera- ting location that is cool and dry. Allow ade- quate ventilation around the heat sinks on the rear panels of both transceiver and power supply.
For normal intermittent transmissions, natural convection cooling is all that is required. During mobile operation, free access to cool air should be provided. Do not direct the  outlet vent of the automobile’s heater directly at the transceiver. To reduce the possibility of stray rf pickup on interconnecting cables, which may cause undesi- rable  parasitic oscillations, and provide a mea~ sure of safety to the operator from possible shock in ac powered systems, 411 station equipment should be well grounded to earth.  It is also im- portant to strap the equipment chassis together with short heavy leads, preferably with braid. This procedure brings all metal components that are accessible to  the touch to the same potential, removing the possibility of shock when touching more than one piece of equipment. Also, the extra strap between transceiver and power  supply chassis serves to reduce voltage loss on the negative 13 volt supply lead caused by resistance in the cable and connector contacts. If a metal operating table is used, be  sure to ground it also, In mobile installations, connect a ground strap be- tween the rear panel GND post and the vehicle’s chassis.
Earth ground leads should be of heavy wire or braid and be as short as possible. Attach secure~ ly to a ground rod driven into the earth near the operating position.

FIXEO STATION INTERCONNECTIONS
A supply of 12 to 14 volts dc, capable of supply- ing 18 to 20 amperes, negative ground, is requir- ed. Voltage regulation of 5% or better between no load and full load is  recommended for distortion- free transmissions, although unregulated supplies may be used without damage to the transceiver. Output power may fall below the specified  value if the supply voltage drops below 13 volts. The transceiver may be operated directly from an auto- mobile battery in fixed locations, provided that the voltage under full  load does not fall below 11 volts. This requirement dictates that the battery be near full charge and that it be a relatively new battery. It is permissible to connect a slow charger across the battery to maintain the full charge condition.

For 115/230 volt ac operation, a well regulated supply is recommended. TEN-TEC Model 280 is fully regulated and has over-voltage and over-current protection circuits.

POWER CONNECTIONS

Power is supplied to the transceiver by means of the 4 pin AMP MATE-N-LOC type 1-480702-0 connector with type 350874-3 female terminals. The chassis connector is of  the male type and mates directly with the cable connector supplied and attached to the Model 280 supply. It is only necessary to in- sert the cable connector inte the chassis  recep- tacle with the red wire in the cable going to the topmost pin marked (+) on the rear panel.
When using a dc source other than the Model e280 supply, it will be necessary to use the cable sup- plied with the transceiver. The cable is 5 feet (i. 5 meters) jong and of  heavy gauge wire. Any excess length shauld be cut off to decrease the voltage drop in the cable to a minimum. The rais-~ ed rib on the cable connector (see detailed draw- ing, Figure 2) is the negative black lead and mates with the bottom chassis terminal marked (-). The positive wire is white in the cable. The con- nectors are keyed so that they  cannot be inserted incorrectly.

An extra power connector is supplied for con-struction of an additional cable, if needed. Wires should be at least 14 gauge with 12 gauge recom mended for long runs. Pin  connections aret Pin 12 GND (negative) and Pin 4 = +DC, Pins 2 and 3 are not needed. Pin i has the raised rib on the cable connector. This cannector is intended for high Production automatic staking of the wires to the terminals. However, it can be assembled in the field without staking Machinery by crimping and soldering the leads to the  terminals, and insert- ing the terminals into the plastic shell. To do this, refer to Figure 2 and proceed as follows:

1. The terminais are supplied connected to a strip of flat metal. Break the individual connectors from the strip by bending back and forth at the point of narrow attachment, or by clipping them off with diagonals,
2. Wire sizes that can be accomodated range be- tween 12 and 18 gauge. Strip insullation 1/4″ back from end.
3. Insert stripped end into barrel far enough so that insulation just starts between large thin and small wide tabs.
4. With long nose pliers, roll over small tabs so that they held bare wire.
5. Solder leads to rolled tabs by applying tip of iron to top of rolled tabs while Feeding rosin core solder between wire and tabs. Do not allow solder to run into hollow tube.
6. After terminals are well soldered, roll large thin tabs down over insulation and crimp with pliers.
7. Insert terminals into plastic shell from solid plastic end so that they finally la- cate in individual tubes. The terminals will automatically lock inta place when inserted to  the proper depth. MAKE ABSOLUTELY CERTAIN THAT TERMINALS ARE INSERTED INTO CORRECT HOLES SINCE REMOVAL IS OIFFICULT.

To remove terminals, an extractor is necessary to collapse the lanced holding tabs on the sides af each barrel. The extractor can be a metal tube, at least one inch (25 mm)  long, with an outside diam- eter between 0.125″ (3.2 mm) and 0.135″ (3.4 mm) and an inside diameter of 0.100″ (2.5 mm). Insert the extractor tube into the pin end of the  shell over the terminal to be removed, to a depth of about 1/2” (13 mm). Pull un the wire and extract the terminal.

ANTENNA CONNECTION

Any matched antenna presenting 50 ta 75 ofms im~- pedance, one side grounded, will load satisfacto- rily. Random length wire antennas arid capen wire feed systems will  require a matching network. Use coaxial RG-5S8 cable between the Model 150 and an- tenna or the transceiver side of the tuner. If a tuner is used, locate it as far as is  practical from the immediate transceiver location. Bo not place tuner on top of transceiver or close to the microphone or cables going to the power source. If different  antennas are used for multiple channel operation, an antenna switch should be used to facilitate antenna changes. Remotely controlled antenna tuners and/or switches can be controlled by the transceiver CHANNEL SELECTOR switch by means of the CHANNEL SWITCH connector and suitable cable. (See CHANNEL SWITCH  CONNECTIONS paragraph below).
The antenna must be matched to a 2 to 1 standing wave ratio or lower. To measure SWR depress the CARRIER switch on the rear panel and observe the SWR scale on the  panel meter. A type PL-2@59 coaxi- al connector is required to connect the antenna lead to the transceiver.

For base installations, we recommend the use of one of our folded dipole broadband antennas (Model FD-2 or FD-3) which does NOT require any matching network or  switching system. Model FD-2 covers the entire 2 through 12 MHz range of the transceiver and Model FD-3, which is one half the length of the FD-2, covers frequencies  above 3. S MHz. Both have standing wave ratios belowdce toi across their operating bands.

CHANNEL SWITCH CONNECTIONS

If a remotely controlled antenna switch, tuner or linear amplifier band switch is to be activated by the transceiver’s front panel CHANNEL SELECTOR switch, control lines  are available at the CHANNEL SWITCH connector on the rear panel. This connector mates with a MOLEX type 03-06-2092 nine pin cable connector with male terminalis  (one supplied with each transceiver). These are similar to those used in the power cable but accept wire sizes between 24 and 30 AWG. Refer to the POWER  CONNECTIONS paragraph above for construction details.
Terminal numbers, which are molded into the cable connector shell, are the same as the charmel switch positions for Pins 1 through 8. Pin 9 con- nects tp the movable  contact on the selector switch. Therefore Pin 3 shorts to the pin that has the same number as the CHANNEL SELECTOR knob posi- tion. All terminals are insutated from  the chassis and (+) supply line.

MICROPHONE CONNECTIONS

The microphone input circuit will accept any low impedance dynamic or electret type microphone, providing it produces at least 5 millivolts of signal. It should incorporate a  normally open Pust To Talk (PTT) switch which shorts to the chassis GNO when in the transmit mode. The TEN-TEC Model 700-C Electret Microphone which is supplied  with the transceiver is especially well suited to and compatible with the transceiver circuits.
The microphone cornector is a standard 4 pin fe- male microphene plug with a threaded locking rang. The pin numbers, which are molded into the plastic portion af the  connector are: Pin microphone signal; Pin GND) Pin PTT line; Pin 4= polar- izing veliteage voitage for Model 7OO-C microphone. If you use a microphone  other than an electret type, Pin 4 does not require a connection.

LINEAR AMPLIFIER CONNECTIONS
To facilitate switching a high power linear ampli-~ fier ‘on’ in the transmit mode, Model 150 incorpo~ rates a T/R relay that is energized whenever the PTT switch 46 closed  or when the VOX option is triggered ta the transmit mode. The contacts for this relay are brought out to the jack on the rear panel marked T/R. The center pin contact  shorts ta chassis GND during transmit. If the relay in the linear that controls this function is a 115/230 volt ac type, do NOT use the T/R line directly ta activate it since it  will connect the transceiver chassis to one side of the ac line – a dangerous Situation. Rather use an intermediate 12 valt de relay. The +12 volts for this relay may be drawn from the AUX 12 VDOC jack an the rear panel. To reduce the possibility of rf pickup on intercon necting cables, use coaxial cable from the T/R  jack, either RG-174 miniature cable or RG-58/59.
If the linear amplifier band changing is to be re- motely switched by means of the transceiver CHAN- NEL SELECTOR switch, refer to the CHANNEL SWITCH CONNECTIONS paragraph above for cable information.

TELEPHONE INTERFACE
Two jacks are provided on the rear panel to gain access to the transceiver’s speaker and microphone lines. The PATCH IN jack connects directly across the speaker, thus  providing an audio signal into the telephone coupler for transmission to the cal-ling party. The voltage level on this line is approximately 1/2 volt under normal speaker  volume and is controlled by the VOLUME control on the front panel. If the telephone coupler requires a lower voltage, a resistor attenuator should be in- serted in the  PATCH IN output line.
The PATCH OUT jack bridges the microphone input line so that the signal from the calling party out of the telephone coupler is applied to the trans- mitter section. Voltage  level from the coupler should be approximately 10 millivolts to match that of the microphone. A separate level control in the coupler’s output is recommended so that a balance between its signal and the microphone level can be attained.
Use shielded cables for both coupler connections, type RG-174 or RG-58/59.

MOBILE STATION INTERCONNECTIONS

POWER CONNECTIONS
Power requirements for mobile operation are the same as those outlined for base stations. When op- erating mobile, a power input cable of 12 gauge wire should be run  directly from the battery ter- minals to the transceiver. Do mot rely on the chassis to provide the negative connection, but run 4 wire directly from the negative battery ter- minal to the Model 150 power connector. Instali Model 150 only in vehicles that have negative ground battery systems.

ANTENNA CONNECTIONS
Most mobile whip antennas will provide a near optimum match to the SO ohm input but only over a very narrow frequency range without readjustment.
In some cases additional matching components may be required to achieve an acceptable SWR below 2 to 1. Since whip antennas use the vehicle’s chas-sis as the ground plane, it is important that the shield of the coaxial cable at the base of the antenna be connected to a good chassis point. Trunk lids and some bumpers may require additional bonding to the main chassis with flexible straps or braid.

Resonating the whip antenna at the operating fre-quency is a relatively easy procedure since the SWR bridge is built into the transceiver. While depressing the CARRIER switch button on the rear panel, the resonant point can be determined by ad-justing the whip length above the coil for minimum SWR. Make changes in 1/8″ or 1/4″ (3 to 6 mm) in-crements since the resonant dip is quite narrow, especially on the lower frequencies. If the SWR is above 2 to 1 at the resonant dip, a better match can usually be achieved by connecting a small ca-pacitor across the base of the antenna to chassis. For single channel operation, the value can be de-termined and the capacitor permenently soldered in place. For multi-channel operation, a rotary switch in a small metal box can be located near the antenna base, in the trunk for instance, and the proper capacitor selected in this manner. Use mica capacitors with at least 500 volt ratings. Typical values for 4 MHz may be between 470 pF and 1000 pF with values decreasing as frequency is in-creased. Addition of the capacitor may require a slight touch-up in antenna length.

Although the noise blanker option is effective in reducing ignition noise, it is best that the in-stallation be such that ignition noise is reduced as much as possible without the blanker. Use of resistor spark plugs and low noise ignition cables and noise suppressors in the distributor circuits are very effective in reducing interference. Also, strap the hood to a good chassis point with flexi-ble metal or braid if it is not already well grounded. Locate the antenna as far as is practi-cal from the engine – either on the rear trunk deck or bumper. And since the muffler and exhaust systems on most vehicles are supported and effec-tively insulated from the chassis with rubber shock mounts, they may carry ignition noise cur-rents to the antenna location at the rear of the vehicle. Strapping the tail pipe or muffler to the chassis may substantially reduce ignition pickup.

OPERATION

NOTICE: Sections 1I and ITI (INSTALLATION and OF-ERATION) of this manual assume that all desired operating crystals and options are installed in the transceiver. If  this is not the case, refer to Section [V, INSTALLING CRYSTALS AND OPTIONS, be-~ fore proceeding with this section.

GENERAL
Special care has been taken in the design of the Model 150 to insure stable frequency characteris- tics. As  consequence, no warm-up time is neces- sary when first turning the  unit on or when chang- ing channels. The unit is ready to transmit or re~ céive the second it is switched on.
The front panel controls that affect both the transmitting and receiving functions are:
POWER ON/OFF – This control provides the dual functions af switching power to the transceiver and protecting the transceiver’s components in the event of certain  malfunctions. It incorporates a fast acting circuit breaker that will trip to the ‘off’ position whenever a current drain of over 24 amperes is asked of the battery or power source.
This situation may be caused by a shorted or im-properly matched antenna, improper supply voltage or failure of the transmitter final amplifier, When the breaker trips, the  meter lamp will ex- tinguish. If this happens, check to see if the ab- normal candition is a temporary one by throwing the switch to the OFF position and then again to ON. If  the breaker trips immediately, without speaking into the microphone, it indicates trouble in the final amplifaer. If ait trips only when speaking into the microphone, it may  be that the antenna system is defective or slightly wut of tune, causing a SWR greater than 2 to 1.
CHANNEL SELECTOR – This control selects the op- erating frequencies as determined by the crystals specified for the various channels.
USB/LSB Switch – When the UL option is installed this switch selects either upper or lower sideband operation for both transmit and receive modes.
Without the UL option, the mode of operation will be that of the installed filter (WU or L) in both switch positions. A clear plastic locking switch plate may be installed in  transceivers without the UL option, in the position correct for the filter thet is installed.

RECEIVING .
Controls that need adjustment when receiving are:
VOLUME – This control sets the level of audio from the speaker. It also sets the level from the PHONES jack on the front panel, as well as the level present at the PATCH  IN jack on the rear panel.
SQUELCH/OFF – When turned fully counterclockwise signals over approximately one microvolt will open the audio channel. As the control is rotated in the clockwise  direction, higher levels of incoming signals will be required to open the audio. In the full clockwise position, the channel will remain closed at all times.
Squelch is most used when monitoring a channel and the background noise is disturbing. With the VOL- UME control set to its normal position, rotate the SQUELCH  control clockwise until the background noise is turned off. Any signal coming in above the noise level will open the audio channel. In cases where atmospheric noise bursts  are present, adjust the SQUELCH control just a bit past where normal background noise is eliminated to catch some of the lower noise bursts. Of course, if they are too  severe, the channel will be opened momen- tarily. To fully disable the squelch function, pull the SQUELCH knob out.
CLARIFIER – This control may be used to adjust the tone of the voice being received to make it more intelligible. Unless the received signal is considerably off frequency, the  control will nor- mally be set to the center position, where a slight detent will be felt.
NB-OFF Switch – If the NB option is installed, this switch turns the noise blanker on and off. A clear plastic locking switch plate may be instal- led in transceivers without the  NB option.
The noise blanker is designed to eliminate or re- duce impulse type noise, such as from automotive ignitions, small dc motors and certain types of ac line noise. Certain  continuous disturbances, such as background and atmospheric noises, are less discernable by the blanker and consequently are not eliminated or reduced to the same degree  as impulse noise.
PHONES Jack – When headphones are plugged into this jack the speaker is automatically disconnect- ed. An extension speaker may also be powered from this jack. Although  the audio amplifier is design- ed for an 8 ohm load, external speakers between 4 and 16 ohms will work satisfactorily. If you de- sire to connect a remote speaker  without disabling the internal speaker, use the PATCH IN jack on the rear panel.
Headphones of any impedance will also work direct- ly from the PHONES jack. However, since the amount of power needed to drive headphones toa satis- factory level is  much less than for a speaker, it is recommended that an attenuator be used between the PHONES jack and low impedance headphones. The attenuator will greatly reduce  residual internal noise. A simple resistor network consisting of a 15 ohm resistor in series with the phones anda shunt resistor of 2. 7 or 3. 3 ohms across the phones should  be satisfactory. The resistors, both 1/4 watt types, can be soldered to the phone plug terminals and concealed in the shell of the male plug. The attenuator is not necessary with high impedance headphones since the power to them is automatically reduced when connected to the low _impedance source.
METER – When receiving, the panel meter -indi- cates relative strength of the signal being re- – ceived. It is calibrated for a 50 microvolt input signal reading of S93. Each ’S’  unit is a ratio of approximately 6 dB or a two-to- one voltage change.

TRANSMITTING

The front and rear transmitting controls are:
PTT-VOX/CW Switch – This switch selects either the Push-To-Talk or Voice Operated Transmit method of switching the transmitter on when the VOX op- tion is installed.  Without this option, only the PTT method is operable and a clear plastic lock- ing switch plate may be installed over the switch actuator. When the microphone PTT lever is  depres- sed the transceiver automatically transmits ssb. There is no transmit/receive switch to actuate. Hold the microphone closely to the mouth and speak Clearly. The  transceiver circuits automatically ade just the level of signal from the microphone so that maximum available power is transmitted. This is indicated by the periodic flashing of  the Light Emitting Diode (LED) over the PTT switch. Tf the LED does not light on voice peaks, hold the micro- phone closer and talk louder.
When the VOX option is installed, either switching mode may be selected by the PTT/VOX switch. In the VOX position the PTT switch on the microphone must be continuously activated. For this reason VOX is most used at the basestation where the microphone, such as the TEN-TEC Model 214, has a toggle rather than a spring return  type of PTT switch. Handheld mobile types do not lend themselves well toa VOX operation. With VOX, whenever sound over a certain level enters the microphone  (internally adjusted), the transceiver automatically switches to the transmit mode. It reverts to the receive mode automatically after a pre-determined period of Silence (also  nternally adjusted).

CW Operation – The VOX option also allows code transmissions. Insert the cw key or electronic keyer into the jack on the rear panel marked KEY. Whenever the key is  depressed a continuous carrier is transmitted either 800 Hertz above or below the channel frequency, depending on whether the trans- mitter is set up for upper or lower  sideband transmissions. This 800 Hz frequency offset elimi- nates detuning a similar receiver listening to the transmitted code that would otherwise be necessary to produce  an audible beat note. When operating cw, both the transmitter and receiver should be operated on the same sideband and carrier fre- quency. When the key is closed a tone  emanates from the speaker to enable the operator to monitor his sending. The volume of this tone is preset inter- nally and is not affected by the front panel VOL- UME control setting.

CARRIER Switch – This push button switch, locat- ed on the rear panel, causes a continuous carrier to be transmitted at the carrier frequency when- ever it is depressed. It is  used whenever antenna SWR measurements are taken, when adjusting antenna or tuner or when calibrating the crystal oscilla- tors. So as not to cause the magnetic circuit breaker to trip when adjusting antennas or tuners, the power output is reduced to a safe level. & frequency counter can be connected to the COUNTER jack on the rear panel  for oscillator adjustments.
METER – When transmitting, the panel meter in- dicates the reflected power. It is calibrated in SWR units based on the reduced power level present when the CARRIER  switch is depressed. Therefore it will be an accurate indication of the degree of antenna match when this switch is actuated. Under normal ssb and cw operation the scale  deflection will be amplified because of the higher power out.
With proper antenna match, the meter should NOT move appreciably from its resting position when talking into the microphone. If it does, check and adjust the  antenna/tuner system by depressing the CARRIER button.

OPERATING HINTS

1. The movable bail is primarily intended to raise . the front to a convenient slanting position. It May also be used as a carrying handle.
2. Due to the possibility of high voltage tran- sients being generated in the rf amplifier dur ing channel switching, change channels only in the receive mode.
3. When operating mobile, always turn transceiver off when starting or stopping the motor. High voltage transients from the generator may ap- pear on the 12 volt line  before the vehicle’s regulator contacts close.
4. A lightning arrestor on all base station an- tenna lead is recommended.
5. During lightning and thunder storms, discon- nect antenna from transceiver and close down operations. Ground all antennas if possible.

IF YOU HAVE TROUBLE
Below is a list of common faults that may cause the transceiver to malfunction. All are caused by faulty components external to the Model 150, or from an oversight on the  operator’s part. If trou- ble is suspected within the transceiver, refer to Section VI, MAINTENANCE, for detailed information.

SYMPTOM – Transceiver dead. No meter lamp = illumination.
POSSIBLE CURES – Operate power switch to OFF posi- tion and then back to ON to reset tripped cir- cuit breaker.
If using a TEN-TEC power supply make sure its switch is on.
Check power cable from supply or battery.
Check battery/supply for correct voltage.
Check 20 ampere fuse inside transceiver on back panel. (Remove top cover.)
SYMPTOM ~ 2O ampere fuse is blown.
POSSIBLE CURES – Check for reverse polarity on 12 volt line. Correct cable wires or connector termination.
SYMPTOM – Both receiver and transmitter dead. Meter lamp lights.
POSSIBLE CURE – Check position of CHANNEL SELECTOR switch for possible setting to a channel that does not have crystal installed.
SYMPTOM – Receiver dead. Transmitter OK,  POSSIBLE CURES – Check to see if headphones are plugged in, disabling speaker.
Make sure SQUELCH is not advanced too far clock- wise. Pull SQUELCH knob out.
Check microphone cable/connector for continuous short between Pins 2 and 3.
If microphone has toggle type PTT switch, make sure it is not in ‘transmit’ mode.
SYMPTOM – Receiver OK. Does not switch to transmit mode when PTT switch on microphone is closed.
POSSIBLE CURES – Check microphone cable, connector and PTT switch.
If VOX option is installed make sure PTT-VOX/CW switch is in PTT position.
SYMPTOM – Receiver OK. Switches to transmit mode but LED does not flash on when speaking into the microphone.
POSSIBLE CURE – Check microphone, cable and con- nector.
SYMPTOM – Set seems alive but received signals are weak or non-existant. High SWR when transmit- ting.
POSSIBLE CURES – Check antenna system and cables. Check settings of tuner if used.
Try dummy load to determine if problem is in the antenna. (SWR should be near 1:1 with 5O ohm dummy load.

INSTALLING CRYSTALS AND OPTIONS

GENERAL
Model 150 may be shipped from the factory with or without channel crystals and/or options, depending on the purchaser’s requirements. Crystals and cer- tain options may  be installed in the field after delivery. This section gives crystal specifica- tions, crystal installation and calibrating pro-cedures, instructions to alter the channel/band scheme  in the Model 150-A units and instructions for anstalling the UL and NB options. The VOX/CW and TFS (Two Frequency Simplex) options cannot be added in the field  since they require replacement of several printed circuit boards and rewiring of several cables.
Model 150-B single band transceivers cannot be modified to result in a Model 150-A four band unit nor is it possible to change a Model 150-B from one band to another.

PROGRAMING
The programming function serves to set up the Model 150-A four band transceiver so that the de- sired channel frequencies correlate with the posi- tions of the CHANNEL  SELECTOR switch. Any fre- quency between 2 and 12 MHz can be assigned to any of the 8 switch positions. This information is programmed into the switching circuits by  means of @ small cable with two removable connectors. To change the program it is only necessary to re- arrange the wires in this cable. NOTICE: If the Model 150-A is  shipped from the factory without any crystals installed, the cable is NOT fabricat- ed – only the two unconnected connectors are in- serted into their mating PC board connectors. The transceiver will be inoperative, even with crys- tals installed. In Model 150-B transceivers no programing is necessary since all channels oper- ate within the  specified band.
To construct or change an existing programing cable, first draw up a table listing the desired operating frequency for each channel, and deter- mine which band is required.
The bands are as follows:
Band 1 – 2 to 3 MHz
Band 2 – 3 to 5 MHz
Band 3 – 5 to & MHz
Band 4 – & to 12 MHz
A typical table might be as follows:

Constructing The Cable
Remove the bottom of the transceiver and locate the BAND SWITCH subassembly, Pt.No. 80994, located at the front left side. Figure 3 is a reproduction of the top printing  on this PC board. The two con- nectors are numbered 54 and 5S. Connector 54 is the ‘band’ connector and has four terminals. Con- nector 55 with eight terminals is the  ‘channel’ connector. Figure 3 shows enlarged views of these with the terminal numbers called out.

The cable connectors are of the insulation-displacement type whereby wire cannections using #24 AWG stranded wire are made by forcing the unstrip- ped wire into the  terminal. The sharp edges of the terminal cut into the plastic insulation on the wire and make a reliable connection without solder. However, a special insertion tool is required to make reliable connections in this manner. For field construction it is recommended that the wire be stripped back about 1/8″ (3 mm) and after being forced into  the terminal with a small blade screw- driver, soldered with a pencil iron and rosin core solder.
Construct the cable using the supplied brown, red, orange and yellow wires by first connecting a a small length of brown wire to the #1 terminal of the ‘band’ connector and  then over to a11 of the ‘channel’ terminais that require that band. Notice that the ‘channel’ connector allows the wire to pass through so that it can be routed to other  ‘channel’ terminals as required. Proceed with the remaining bands.
In our example, the cable will be constructed as follows:

1. A brown wire will connect to ‘band’ terminal #1 and to ‘channel’ terminals #1, #2 and #5.
2. A red wire will go from ‘band’ terminal #2 to ‘channel’ terminal #3.
3. A yellow wire will go from ‘band’ terminal #4 to ‘channel’ terminal #4.

Notice that there will be no wire connected to ‘band’ terminal #3 since we do not require any 5 to 8 MHz operation. Also, the terminal sequence on the ‘band’ connector is  not in numerical order but in the order 1,4,3,2 from top to bottom.

CRYSTAL SPECIFICATIONS

To meet published specifications it is imperative that crystals used in the Model 150 be of high quality and conform to the rigid specifications given here. They should be  properly aged for maxi- mum stability. The channel frequencies designated in these specifications are of the carrier and not the mid-channel frequency. In this way, the speci-  fied crystal frequency will be the same for either upper or lower sideband operation.
CASE: HC2S/U (Plug in terminals)
MODE: Fundamental
RESONANCE: Parallel
LOAD CAPACITY: 30 pF
TEMPERATURE VARIATION: +/-SO Hz max. O to 40 degrees Celsius from the 25 degree value.
FREQUENCY TOLERANCE: .002% EQUIVALENT RESISTANCE: 14-15 MHz = 22 ohms
15-20 MHz = 2O ohms
20-25 MHz = 18 ohms
SHOCK: Maximum frequency change = .O0005%
Maximum resistance change = 10%
VIBRATION: Maximum frequency change = .0005%
Maximum resistance change = 10%
AGING: Maximum frequency change = .0005%
MARKING: Channel carrier frequency in MHz on top Crystal oscillating frequency on side
FREQUENCY: 12. 700000 + Channel Carrier Frequency in MHz

CRYSTAL INSTALLATION
Access to the crystals and calibrating components is by removal of the small cover plate on the bottom of the transceiver. The crystals are plugged into the multi-socket  starting with Channel 1 Closest to the front of the transceiver and pro- ceeding toward the rear. Fiqure 4 is a reproduc- tion of the printing on the top of the XTAL OSCIL- LATOR printed circuit assembly to which the crys-~ tal socket is attached. The crystal positions are clearly marked.

Insert the appropiate crystals into their sockets, which are arranged in two groups of four. If the crystal cases do not have insulating plastic Sleeves over them, place one of  the small rubber bands supplied in the packing kit around each group of four or less crystals so that the cases touch one another. Intermittent contacts between cases will  affect the oscillating frequency toa small degree if this is not done.

OSCILLATOR CALIBRATION

The small variable capacitors that calibrate each channel are also on the same printed circuit assembly and run along the left side of the board. The printed designations from  1 to & are plainly visible. To calibrate the oscillators proceed as follows:

1. Remove small cover plate from bottom of the transceiver. Do NOT remove bottom cover.
2. Connect output from the ANTENNA jack to a SO ohm dummy load and power transceiver in the normal manner.
3. Connect an accurate frequency counter to the COUNTER jack on the rear panel. The counter should be capable of reading to 1 Hertz and be accurate to 5 Hz.
4. Rotate CHANNEL SELECTOR knob to channel that is to be calibrated.
5. Depress CARRIER pushbutton on rear panel and hold in while observing frequency counter. Using an insulated tuning wand, carefully adjust the corresponding  capacitor so that counter reads the proper channel carrier frequency to within 5S Hz. The adjustment is very critical.

UPPER AND LOWER SIDEBAND FILTERS
The UL option provides both upper and lower side-band operation. If the transceiver does not pres- ently have this option installed it will have either an upper or lower  sideband filter, but not both. The filters are located on the SSB printed circuit assembly, No. 80388, accessed by removing the top of the transceiver. A reproduction of the  printing on this board is given in Fig. 5. The filters are in rectangular metal cans, the USB filter located in the right center area and the LSB filter in the lower right. To install  the missing filter proceed as follows:

1. Remove top of transceiver by removing four side screws.
2. Unplug all cables going to this assembly, Notice that they are numbered both on the  assembly and cable connectors. The two con- nectors in the upper left corner may  or may not have cables connected, depending on whether the VOX/CW option is installed or not. Also notice that there is a shorting Plug in PC connector #81.  Remove this con-nector also.
3. Remove the four screws at the corners of the assembly and lift assembly out.
4. Install the additional filter in the loca- tion provided and secure it with the 4-40 hex nuts and washers supplied.
5. With a small pencil soldering iron, solder the two remaining pins to the board, using rosin core solder.
6. Reinstall the assembly into the chassis. Make sure that the four tubular standoffs that space the board from the chassis have not fallen off of their retainers.
7. Reconnect a11 cables to their respective PC board connectors. Notice that when the con- nectors are correctly installed, the wires exit from the connector away from the  raised locking tab on the PC board connectors. It is possible to incorrectly plug the cables into their sockets. (Observe other cables in transceiver for proper orientation. )
8. Plug the three wire cable supplied with the option into connector #81. Route this cable to the left side of the chassis and then forward to the toggle switch assembly on  the front sub~-panel.
9. Piug this end of the cable into the first three pins of the 9 pin connector on the toggle switch assembly that are nearest the left side of the transceiver. The wires coming  from this connector should exit down-ward toward the chassis plate. FAILURE TO INSERT THE CONNECTOR CORRECTLY WILL RESULT IN IMPROPER  TRANSMISSIONS.
10. Replace top cover.
    Addition of the UW option does not require any alignment or circuit adjustments.

INSTALLING NOISE BLANKER
The NB option is easily added to the Model 150 as follows:

1. Remove top cover by removing foun screws.

2. The blanker assembly will be located immedi- ately behind the SSB assembly, in the upper left area. (Gee Figure 3, Inside Top View)

3. Insert the four retainers supplied with the blanker into the four mounting holes in the assembly from the top as shown in Fig. 6. Push four spacers over the retainers  from the bottom. Insert four #4 sheet metal screws through the retainers from the top.

4. Carefully move any cables away from the area where the blanker will be mounted and posi- tion the board over the four small holes in the chassis that match the screw  locations.
   Orientation should be such that the printing on the PC assembly is upright and matches that of the other assemblies.

5. Remove the short two wire cable between con- nectors #37 on the SSB assembly, Pt. 80988, and #37 on the TX-RX MIXER assembly, No. 80989, to the right of it.

6. Install the longer shielded cable supplied with the blanker between connector #86 on the bianker assembly and connector #37 on the SSB assembly. (Refer to UL option  infor- mation above for proper connector orienta~- tion.)

7. Connect the short shielded cable supplied between connector #85 on the blanker and #37 on the TX-RX MIXER.

8. Plug the two terminal connector #59 of the two wire cable into the mating connector on the blanker and route the cable along the left side of the chassis to the toggle switch assembly on the front sub-panel.

9. Plug the three terminal connector on this end of the cable into the three pins of the 9 pin connector on the toggle switch assem- bly that are farthest to the right. The wires should exit from this connector point- ing toward the chassis plate and not toward the top of the transceiver.

10. Locate the two wire cable with connector #83 that is installed in the Model 150 but not connected to any assembly. Insert it into connector #83 on the blanker.

11. Secure the cables with the plastic cable ties supplied with the option.

12. Replace top cover.
    Addition of the N8 option does not require any alignment or circuit adjustments. The assembly has been pre-tuned at the factory.

CIRCUIT DESCRIPTION

GENERAL
This section analyses the circuit design of the Model 150 in a general way. Both received and transmitted signals are traced through the various stages of the transceiver with  the aid of the Block Diagram, Figure 7. Detailed information on the locations of the components used in the vari- ous sections is given in the alignment and servicing  sections that follow.
The circuit approach used in the Model 150 represents the latest techniques developed for transistorized hf equipment. Both transmitter and receiver are wideband so that the  operator is not required to adjust any tuned circuits in the use of the transceiver. The receiver front end is design-  ed without an rf amplifier to achieve superioroverload  characteristics in cases where strong interfering signals are present. This is accomp- lished by feeding the antenna signal through a series of band pass and low pass filters and  then directly to a high level diode ring mixer. The all solid state design results in prolonged component life due to lower operating temperatures within the unit and also  simplifies battery, mobile and portable operation.

RECEIVER CIRCUITS
Referring to Figure 7, notice that all paths for the received signal are represented by solid lines connecting the various stages. The transmitted paths are dotted.
Starting at the antenna, the signal first travels unchanged through the SWR BRIDGE, which isa transmitting function. From there it passes through a 7 pole LOW PASS  FILTER whose cut-off frequency is slightly higher than the high end frequency of the band in use. [n the Model 150-A, this filter is selected by the position of the CHANNEL SELECTOR switch an the front panel. In  Model 150-B, the filter is permenantly installed  for the particular band designated in the specifications. The filter  eliminates all signals higher in frequency than the operating range, that may interfere with the desired signal, especially when the undesired signal level is high.
The output from this filter is passed through a 14 pole BANO PASS FILTER whose range is 2 to 12 MHz.
This further attenuates signals above the trans- ceiver‘’s range and also eliminates those below 2 MHz that may interfere. Within this filter are two trap filters tuned to 18. 7  MHz, the intermediate frequency of the transceiver, effecting a very deep notch at this frequency. This eliminates any signal coming into the antenna circuit at 12.7 MHz from  passing directly through the i-f amplifier. From the filters the signal is applied to the TX-RX MIXER stage. This mixer is made up of 8 diodes in a ring configuration  fed by two trifilar trans- formers. The local oscillator signal comes’ from the CRYSTAL OSCILLATOR whose frequency is selected by the BAND SWITCH.

From the mixer, the 12. 7 MHz converted signal, which may contain either upper or lower sidebands, passes through the ist I-F AMPLIFIER, which is broadly tuned. If the  optional noise blanker is installed, the signal then is sent through a gated amplifier in the option, which turns the amplifier off during noise pulses. The output from the blanker, if installed, or the ist I-F AMPLIFIER is  then passed through the & POLE FILTER, ai crystal filter with a 2@. 4 kHz bandwidth and very steep skirt attenuation.  Depending on whether an upper or lower sideband filter is in the circuit, the output from this sharp filter will contain either the upper or lower sideband frequencies, but not both. From there the signal is amplified further in the 2nd I-F AMPLIFIER. The gain of this stage is con-trolled by the AGC voltage fed to it from the AGC AMPLIFIER AND DETECTOR. The PRODUCT DETECTOR con-verts the signal to audio and amplifies it in a single integrated circuit stage. Carrier injec-tion of 12. 7 MHz to the PRODUCT DETECTOR comes from the CARRIER/BFO OSCILLATOR stage which con-tains a crystal controlled 12. 7 MHz oscillator. The CLARIFIER frequency shift is generated in this oscillator with a varicap diode in the crystal circuit.

Output from the PRODUCT DETECTOR is routed to the AGC AMPLIFIER AND DETECTOR where it is further amplified and changed into a corresponding dc con-trol voltage. This voltage drives the S METER and sets the i-f gain. Audio from the detector is also applied to the AUDIO AMPLIFIER through the SQUELCH gate. The squelch operates from a portion of the dc AGC voltage whose level is determined by the setting of the SQUELCH control.
Output from the AUDIO AMPLIFIER is transformer coupled to the speaker and/or headphone jack. If the VOX option is installed, it is also applied to the anti-vox portion of this option to prevent the sound of the incoming signal from turning the transmitter on. Audio from the primary side of the output transformer is applied to the PATCH IN jack on the rear panel for transmission into the tele-phone coupler.

TRANSMITTER CIRCUITS
The dotted paths in Figure 7 denote transmitted signal flow. Two signals, one an audio frequency voltage originating at the microphone, and the second a 12. 7 MHz rf voltage from the CARRIER/BFO OSCILLATOR combine in the BALANCED MODULATOR to generate the basic sideband signal. Audio from either the microphone or the PATCH OUT jack is ap-plied to the 1st MICROPHONE AMPLIFIER, through the MIC GAIN control and into the 2nd MICROPHONE AM- PLIFIER/COMPRESSOR. The second amplifier also has circuits to automatically adjust the overall out-put level to a preset average value. Therefore if the operator speaks in a loud or soft voice, or moves the microphone closer to or farther from his lips, the automatic feature acts to offset these differences so that the transmitted signal is more closely held to 100% modulation.
Output from these stages is set with the DRIVE control, to the level required by the BALANCED MODULATOR. Both the DRIVE and MIC GAIN controls are internal adjustments.

This audio, in combination with the rf from the CARRIER/BFO OSCILLATOR, generates a 12. 7 MHz double sideband, suppressed carrier signal that is applied to the 6 POLE FILTER, the same one that is used in the receiver. The filter passes only the desired sideband to the TX-RX MIXER stage. Again the proper local oscillator is applied to the transmit mixer from the CRYSTAL OSCILLATOR sec-tion. Output from the mixer, which is now convert-ed to the channel frequency, is amplifier in the LOW LEVEL AMPLIFIER and then to the 100 watt level in the RF POWER AMPLIFIER. The LOW LEVEL AMPLIFIER gain is adjusted automatically to the proper level by means of a dc control voltage derived in the SWR BRIDGE circuit. This automatic power leveling circuit prevents overmodulation in the event that too high a signal is developed in the previous stages. Signal splatter and spurious emissions are prevented in this manner.

Since the output from the RF POWER AMPLIFIER con-tains many harmonics of the channel frequency, they must be removed before being transmitted. The LOW PASS FILTER accomplishes this very effective-ly. This filter is the same as that used in the receiver section and is selected for high end cut-off by the CHANNEL SELECTOR setting through the BAND SWITCH programming. From the filter the sig-nal passes through the SWR BRIDGE where the re-flected power is sensed and indicated on the SWR METER. The forward power is sensed and applied as a dc control voltage to the LOW LEVEL AMPLIFIER.

If the VOX/CW option is installed, several addi-tional functions operate in the transmit mode. First, an audio signal from the output of the 1st MICROPHONE AMPLIFIER is applied to the VOX circuit where it is amplified and converted into a dc con-trol voltage that switches the T/R RELAY to trans-mit whenever the level is above a preset value. In addition, the PTT line from the microphone switch is applied to the PTT/VOX SWITCH portion of the option instead of directly to the T/R RELAY. The position of the PTT/VOX switch on the front panel determines which mode is operative.

When code is transmitted the KEY closure switches the transceiver into the transmit mode and turns on the 800 Hertz oscillator. Output from this oscillator is injected into the 2nd MICROPHONE AM-PLIFIER and on to the BALANCED MODULATOR where it is converted into sidebands of the carrier fre- quency. The transmitted frequency, therefore, is either 800 Hertz above or below the carrier de-pending on what filter is in the circuit. A por-tion of the 800 Hertz signal is also applied to the AUDIO AMPLIFIER to serve as a monitor tone for the operator.

CONTROL CIRCUITS
The various circuits are powered by means of four basic voltages, two of which are controlled. Com-mon circuits to the transmitter and receiver sec-tions are fed from either the constant 13. 5 volts or from a well regulated 8 volts. Also since cur-rents are high in the final RF POWER AMPLIFIER, the 13. 5 volts to the final transistors’ col-lectors are applied at all times except when the unit is turned off. There are two controlled volt-ages designated the ‘R’ voltage that is present whenever the receiver is operative, and the ‘T’ voltage when transmitting. Both of these are 13.5 volt sources and are switched on and off by the T/R RELAY which, in turn, is controlled by a tran- sistor switch activated either by the PTT switch in the microphone or the output from the VOX con-trol circuits. The final rf amplifier is turned on by application of the proper bias provided by the ‘T’ voltage.

Other control circuits include two transistor switches that insert either the upper or lower sideband filter when the UL option is installed. The transistors control switching diodes in the filter’s input and output circuits. The NB option is turned on with the front panel switch that ap-plies +13. 5 volts to the noise blanker gating am-plifier. The other NB circuits are powered in the receive mode from the constant 13. 5 volts and are by-passed in the transmit mode through diodes that are switched on by the ‘T’ voltage. Finally, the low power TUNE circuits are activated with the CARRIER pushbutton switch on the rear panel. De-pressing this switch first turns on the transmit- ter through the T/R RELAY and also unbalances the BALANCED MODULATOR to a small degree so that the correct amount of carrier frequency is applied to the 6 POLE FILTER.

MAINTENANCE

GENERAL
This section gives detailed alignment and service information to keep the Model 150 operating at peak performance levels. Six major areas are cov-ered as follows:

1. List of necessary test equipment.
2. Chassis wiring information.
3. Internal adjustments.
4. Signal tracing and locating faulty circuits.
5. PC board replacement.
6. PC board repair.

TEST EQUIPMENT
Equipment required to service Model 150 includes:

1. Power Supply. 13.5 V dc 20 A, regulated.
2. Dummy Load. 50 ohm, 100 watt resistor.
3. Rf Wattmeter. 200 watts range, 50 ohm line. Good to 25 MHz, minimum.
4. Signal Generator. 2 to 15 MHz. Attenuator to 1 microvolt output.
5. Oscilloscope. Frequency range to 15 MHz mini-mum. 10 millivolts to 100 volts rms input. 10 to 1 low capacitance probe.
6. Audio VTVM. 10 millivolts to 10 volts rms.
7. Frequency Counter. 25 millivolt input. 2 to 15 MHz range. 1 Hz resolution. 5 Hz accuracy. High impedance input or 10 to 1 probe.
8. Audio Oscillator. 300 Hz to 3 kHz. Attenuator to 1 millivolt output.
9. Small Tools. Tuning wands, screwdrivers, cable assortment, etc.
10. Volt-Ohm-Milliammeter. 0•20 VDC, 0-1 ADC Additional equipment that is desirable but not essential includes:
11. Spectrum Analyzer. To 50 MHz, minimum. Cali-brated scales and input attenuator.
12. Two Tone Oscillator. Typically 800 Hz and 1.4 kHz signals. Pure tones with adjustable levels. Attenuator to 1 mV output.

CHASSIS CABLING
Model 150 is constructed using removable printed circuit assemblies that are interconnected with plug-in cables. The assemblies are mounted to the chassis on both top and bottom surfaces using three or more stand-off spacers. Refer to Figure 6 for mounting details.
Cables connecting the assemblies are numbered on both ends as are the mating connectors on the PC assemblies. Figure 8, Cable Wiring Diagram, de-tails all chassis connectors routed between the assemblies as well as cables going to controls, meter, switches and other chassis mounted compo-nents. The dotted cables are those used with the NB and VOX options. Placement of the connectors in Figure 8 with regard to the PC assembly outlines is essentially that of the actual connector loca-tions on the PC boards. The locking tabs on the PC connectors are represented in the drawing as double lines. Wires from the cable connectors should exit away from the locking tabs when cor-rectly plugged in. The LED cable is operable in only one orientation.

INTERNAL ADJUSTMENTS
In addition to the 8 channel frequency calibra-tions, there are 26 internal adjustments located on the PC assemblies. Nine of these are set while in the receiving mode and 17 while transmitting. Figures 9 and 10 are inside views of the top and bottom of the main chassis and all components that require adjustments are shown clearly. They are also denoted in the printing on the tops of the assemblies.
Since some of the settings are affected by other adjustments, it is recommended that they be made in the order outlined below. The following proce-dures assume that the transceiver is in working order.

RECEIVER ADJUSTMENTS
CAUTION: When making most receiver adjustments, the signal generator is connected to the ANTENNA connector. DO NOT switch the unit into the trans-mit mode with the generator connected or it may be damaged. To prevent accidental transmissions, un-plug cable 53 located on the LOW LEVEL AMP. assem-bly but make sure that it is reconnected after completing the receiver alignment.

12.7 MHZ I-F TRAPS
These two traps are located on the TX-RX MIXER as-sembly and are marked NULL. Set CHANNEL SELECTOR switch to the highest frequency channel, prefera-bly one in the 8-12 MHz band. If Model is 150-B, select highest frequency channel in its band. Apply a signal of approximately 12. 7 MHz to the ANTENNA connector from a signal generator and ad-just its level so that an S Meter reading of S4 or S5 is obtained. Adjust generator frequency so that S Meter peaks. Actual frequency will depend on whether upper or lower sideband is being used. Ad- just both NULL capacitors for minimum meter de-flection„ using an insulated tuning wand. Read-just generator output to keep reading below S5. Null is very sharp.

I-F AMPLIFIER
There are two tuned inductances designated L4 and L5 on the IF/AF assembly that require peaking. Ap-ply a small amount of signal from the signal gen- erator at any channel frequency to the ANTENNA connector. Rotate CHANNEL SELECTOR switch to the channel of the same frequency and set generator level for an S4 meter reading. Adjust L4 and L5 for maximum deflection, keeping input level below S4 or S5.

NOISE BLANKER
If the NB option is installed. also peak T1 trans-former on this assembly for maximum meter deflec-tion, keeping input level below S4 or S5. Ti is the larger metal can on the PC board. The smaller one is designated L6 and is a broadly tuned com-ponent that rarely needs adjustment. In the event that impulse noise is present when an antenna is connected to the transceiver, switch NB on and ad-just L6 for minimum noise in the speaker. (It is recommended that the position of this coil core be noted before attempting any adjustment and that the number of turns and direction also be noted when changing the core. In the event that no im-provement in noise blanking is evident, return the core to its original position. The type of noise present may not be of the type that is reduced by the blanker.)

S-METER CALIBRATION
Apply a 50 microvolt signal to the ANTENNA con-nector at a channel frequency between 3 and 7 MHz with Model 150-A units or midband with 150-Bs. Fine tune generator frequency for a maximum S-Meter deflection. Adjust trim potentiometer des-ignated S MTR on the IF/AF assembly for a meter reading of S9.

CARRIER OSCILLATOR
There are two adjustments to the BFO oscillator on the CARRIER OSC. assembly. Trimmer capacitor C3 adjusts the frequency in the receive mode and trim potentiometer R4 sets it in the transmit mode. C3 must be adjusted before R4.
To set the frequency, first make sure that the CLARIFIER control is set to the center detent po-sition. Connect the frequency counter to the #89 connector on the CARRIER OSC. assembly. Access to this point may be obtained by connecting the counter across the 680 ohm resistor located di-rectly below the 89 on the board printing. The grounded end of the resistor is the lead farthest from the connector. To insure minimum loading of the oscillator circuit, connect the counter through a low capacitance 10 to 1 probe if avail-able. Adjust C3 for a counter reading of 12.700000 MHz. To adjust R4, leave the counter connected. Connect a 50 ohm dummy load to the ANTENNA connector and place the unit in the transmit mode by using the PTT switch on the microphone or by shorting Pin 3 of the MIC connector to chassis. Adjust R4 for the same 12.700000 MHz counter reading. The frequency should not change more than 5 Hz between the transmit and receive modes.
IMPORTANT NOTICE: Whenever the BFO frequency is changed, it results in a change in ALL channel op-erating frequencies. Therefore the individual channel oscillator crystals MUST be recalibrated whenever the BFO is readjusted. Crystal calibrat-ing instructions are given below.

TRANSMITTING ADJUSTMENTS

POWER AMPLIFIER BIAS
This control is located on the small PC assembly 80575 that is attached to the outside cover of the RF POWER AMPLIFIER. To access this trim potenti-ometer, remove the top of the transceiver and the top shield covering the rear section of the unit. The control can be reached with the forefinger ex-tended to it near the fuse. The potentiometer may also be accessed with a small insulated screwdriv-er inserted into the lower square cutout in the left side plate. This requires the removal of the bottom also.

To make the adjustment, locate the heavy red lead with the ferrite bead on it that goes between the left fuse terminal and the solder lug on the RF POWER AMPLIFIER assembly. Unsolder only this wire at the fuse terminal and connect a 0 to 1 ampere dc meter in series with this lead. With the dummy load connected to the ANTENNA connector, place the unit in transmit by shorting Pin 3 of the MIC con-nector to chassis. (Do not use the microphone PTT switch in this case since any room noise will mod-ulate the transmitter and cause a false adjust- ment. ) Adjust the bias potentiometer for a 500 milliampere reading. After adjustment is made, re-solder the red lead to the fuse terminal.

BALANCED MODULATOR
Rf transformer T1 on the SSB assembly is a broad-ly tuned circuit. To adjust, connect a dummy load through an rf wattmeter to the ANTENNA connector. Insert approximately 2 millivolts of a 1 kHz audio signal into Pin 1 of the MIC connector. Pin 2 is chassis ground. Make sure that level is low enough so that LED does NOT light when Pin 3 of the MIC connector is shorted to chassis. Adjust T1 for maximum power output as indicated on the watt-meter. (Keep output power below 50 watts during this procedure by adjusting audio input level.)

CARRIER BALANCE
Two potentiometers, both labeled NULL, are locat-ed on the SSB assembly. With a dummy load connect-ed to the ANTENNA connector and the rf oscillo-scope across the load, place the unit in transmit mode by shorting Pin 3 of the MIC connector to chassis. To reduce all possibility of hum modu-lating the transmitter from the open microphone line, short Pin 1 of the MIC connector to chassis also. Alternately adjust the two NULL controls for minimum ‘scope deflection. It should be less than 700 millivolts peak to peak.

SWR BRIDGE NULL
There are two adjustments to the SWR bridge cir-cuit, both located on the LOW PASS FILTER board. Access to these is direct if the top rear shield is removed, or through the openings in the shield marked NULL and SWR CAL. With a 50 ohm dummy load connected ‘to the ANTENNA connectnr press the CAR-RIER pushbutton on the rear panel of the trans-ceiver. The CHANNEL SELECTOR switch should be set to the highest frequency channel. Adjust the trim-mer capacitor (NULL) with an insulated tuning tool for a minimum panel meter reading. The reading should go down to the ‘1’ on the SWR scale if the load is a pure 50 ohm resistance. The SWR CAL. ad-justment must be performed after certain other ad-justments below.

LED ADJUSTMENT
The Light Emitting Diode modulation indicator re-quires a threshold adjustment. This potentiometer is labeled LED ADJ. and is located on the LOW LEV-EL AMP. assembly. Put the unit into the transmit mode without modulation by shorting Pin 3 of the MIC connector to chassis. Adjust LED ADJ. control so that LED is definitely out but not too far past this setting. This is not a critical adjustment but if it is set too close to the turn-on point, it may stay on if the supply voltage to the trans-ceiver rises above that used when making the ad-justment.

POWER OUTPUT ADJUSTMENT
The maximum available rf output power from the transceiver is automatically kept to a preset level. The control that sets this level is located on the LOW LEVEL AMP. assembly. It is an unmarked potentiometer located just to the left of connec-tor 75. Connect a wattmeter and dummy load to the ANTENNA connector and a 1 kHz audio signal of approximately 5 millivolts to Pin 1 of the MIC connector. Put unit in transmit mode by shorting Pin 3 of the MIC connector to chassis. Adjust the 1 kHz level until either the wattmeter reads 100 watts or until the LED comes on.

1. If meter reads 100 watts without the LED coming on, turn trim potentiometer until output decreases to 90 watts at which point the LED should come on.
2. If wattmeter reads below 90 watts when LED just comes on, increase 1 kHz signal slightly and readjust potentiometer so that output rises to 90 watts and LED comes on.
3. If wattmeter reads approximately 90 watts at the point where LED just comes on, no adjustment is necessary.

CARRIER LEVEL IN TUNE MODE
When the CARRIER pushbutton on the rear panel is depressed, approximately 25 watts of carrier out-put power should be generated across the 50 ohm dummy load. This level is set with the CAR. LEVEL control located on the SSB assembly. With the rf wattmeter and dummy load connected, depress the CARRIER button and adjust CAR. LEVEL potentiometer for a wattmeter reading of 25 watts.

SWR CALIBRATION
To calibrate the SWR meter scale, either a 25 or 100 ohm, 100 watt non- inductive resistor is re-quired. Two 50 ohm dummy loads connected in paral-lel will provide a 25 ohm load. While activating the CARRIER switch, adjust SWR CAL potentiometer on the LOW PASS FILTER assembly so that the panel meter reads ‘2’ on the SWR scale, indicating a 2 to 1 ratio. If a 100 ohm load is used, the SWR is still 2 to 1.

MICROPHONE AMPLIFIER ADJUSTMENTS
There are two adjustments in the microphone audio stages. They are located on the SSB assembly and are marked MIC GAIN and DRIVE. They interact with each other and the final settings determine the degree of audio compression in the amplifier. The desired degree of compression is dependent on sev-eral factors. First, if various personel are to use the equipment rather that only one operator, more compression is desirable to offset the varia-tions in their voice characteristics and micro-phone placement. Second, if there is considerable room or background noise present, less compression is desirable so that these noises do not become a major modulating factor when not speaking into the microphone. Generally, it is more desirable to set up the system with less compression than would seem normal since the undesirable factors will not be as prominent and full modulation can still be attained by observing the LED indicator and ad-justing your voice level and microphone placement. The set-up information given below is for an aver-age set of conditions and is that used for factory adjustments.

1. Connect dummy load to ANTENNA connector and at-tach microphone that is to be used to MIC jack.
2. Initially set MIC GAIN control full on. To do this, turn the blue plastic rotor on the con-trol fully counterclockwise when viewed facing the blue disk.
3. Press PTT switch on microphone and while speak-ing forcefully or whistling into the microphone adjust DRIVE control on SSB assembly to the point just past where the LED comes on.
4. Move microphone away from the lips to a dis-tance judged to be the maximum that would nor- mally be used when transmitting.
5. Again press PTT switch and talk in a normal voice. Readjust the MIC GAIN control downward to a point where the LED flashes only on voice peaks. Further movement of the microphone away from this point should cause the LED to remain unlit.

These are normal settings and both controls should be near their mid-rotation points. To decrease compression level, increase DRIVE setting slightly (counterclockwise rotation) and make corresponding decrease in MIC GAIN setting (clockwise).

VOX/CW ADJUSTMENTS
If the VOX option is installed, there are six con-trols on this assembly that require adjustments.

1. MIC GAIN: Initially set the ANTI control fully off. This is done by turning the rotor fully clockwise when viewed head on. Connect a dummy load to the ANTENNA connector and the micro-phone to the MIC connector. Set the PTT-VOX/CW toggle switch to the VOX/CW position. If the microphone has a toggle PTT switch, set it to the normally transmit position. Without speak-ing into the microphone the transceiver should remain in the receive mode. While talking in a normal voice, adjust MIC GAIN control on the option assembly so that unit switches reliably into the transmit mode. If control is advanced too far, background room noise may put unit into transmit mode.

2. DELAY: While still operating as above, adjust control marked DELAY so that unit does not re-vert to the receive mode between words or sen-tences, but does after approximately one second of silence.

3. ANTI: This adjustment is made in the receive mode. Set up the transceiver as it would nor-mally be placed on the table. Insert the micro-phone into its connector and place it where it normally would be when operating. Set PTT-VOX/ CW toggle switch to VOX/CW and PTT switch on microphone to the transmit position. Connect an antenna to the unit and while receiving a sta-tion and not talking into the microphone, ad-just ANTI control so that unit does not cycle into the transmit mode merely from the sound emanating from the speaker. Check to see that unit does switch to transmit when speaking into the microphone, since the ANTI adjustment has a slight effect on microphone gain. If needed, touch up MIC GAIN control.
   There are three adjustments on the VOX/CW assembly that are used when sending code.

4. 800 HZ PEAK: Insert a key into the KEY jack on the rear panel. Set PTT-VOX/CW toggle switch to VOX/CW position. Connect an ac VTVM across con-nector 49 and rotate MONITOR control to mid. position. While holding key down, adjust 800 HZ PEAK control for maximum VTVM reading.

5. MONITOR: With key still depressed, adjust MON-ITOR control so that level of tone coming from speaker is satisfactory.

6. CW LEVEL: This control should be set just past the point where the LED comes on when key is depressed. If the MIC GAIN and DRIVE controls on the SSB board are readjusted, the CW LEVEL should also be reset.

CHANNEL CRYSTAL CALIBRATION
Information to calibrate the individual channel crystals to their correct operating frequencies is given on Page 10 of this manual. If any adjustment is made to the carrier BFO oscillator, all crystal frequencies will have to be recalibrated accord-ingly.
It is important that the crystals be calibrated with the bottom cover in place, since there may be a slight frequency change due to the capacitive effects from the bottom.

LOCATING FAULTY CIRCUITS
To quickly locate the trouble area, make a close analysis of all symptoms of the malfunction. First determine if the problem is present in the receive mode, transmit mode or  both. Also ascertain if it appears on one, several or all channels. This will Narrow down the area as follows;

1. Fault Only In Receive Mode:
   NB option if installed. IF/AF assembly.

2. Fault Only In Transmit Mode:
   LOW PASS FILTER assembly.
   RF POWER AMPLIFIER assembly.
   LOW LEVEL AMP. assembly.

3. Fault In Both Modes:
   TX-RX MIXER assembly.
   CARRIER OSC. assembly.
   XTAL OSCILLATOR assembly. SSB assembly.
   BAND SWITCH assembly.
   VOX option if  installed.

4. Fault Only Gn One Or Several Channels:
   LOW PASS FILTER and its relay circuit.
   BAND SWITCH control and diode switching.
   XTAL OSCILLATOR circuit and crystals.

Visual inspection of a suspected assembly may immediately uncover the trouble area. Look for browned resistors that indicate overheating, loose leads on components or a  browned circuit path. Make sure that all cables are well seated in their sockets. Inspect connections on panel mounted com- ponents for cold solder joints.
Tf the visual inspection shows no signs of defec- tive components, check the dc supply voltages to the suspected assemblies. The four voltage lines running throughout the  transceiver have color coded wires in the cables, simplifying voltage checks. The constant 13. 5 V line is RED, the con- stant regulated 8 V line is ORANGE, the 13.5 V transmit (T) line is BLUE and the 13.5 V receive (R) line is VELLOW. All cables originate at the DISTRIBUTION BOARD assembly. If voltage is present at this end of the  cable but not at the assembly end, make sure that the cable is not faulty. The insulation displacement method of connection is very reliable but is not perfect. If a connection in the cable connector is suspected of being faulty, try applying a little pressure on the wire in the connector with a smali bladed = screwdriver while observing the voltmeter  to see if the con- nection is intermittent.
If all cables check out satisfactorily, the fast- est procedure to return the transceiver to opera- ting condition is to start replacing the suspected PC assemblies. TEN-TEC spare  parts kits BRF and RSK each have a set cf replacement PC boards that can be substituted one at a time. Repair of the faulty board is covered below.

REPLACING PC ASSEMBLIES
Replacement of assemblies is a simple task. All PC boards except the RF POWER AMPLIFIER/BIAS assembly are secured to the chassis with three or more screws and stand-off spacers. The RF POWER AMPLI-FIER is attached to the rear panel with four ma-chine screws.
To access the LOW PASS FILTER assembly, it is nec-essary to first remove the rear panel. The white wire going from the ANTENNA connector to the as-sembly will have to be unsoldered at the connector terminal. Several cables going to the RF POWER AM-PLIFIER and the heavy red lead from the fuse post will have to be disconnected before the rear panel can be swung out of the way.

To remove either the BAND SWITCH or the IF/AF as-sembly, the front panel knob/s attached to the controls that are mounted on the assemblies must first be removed. Then with a flat 1/2″ (13 mm) wrench, loosen the shaft nut/s located between the front panel and the sub-panel. There is one on the BAND SWITCH assembly and two on the IF/AF board. As the assembly is removed, loosen the nut/s until they are completely free of the threaded shaft. Also, it may be easier to remove the IF/AF as-sembly if the CARRIER OSC. board is first removed.

Unplug all cables going to the assembly to be re-moved and move them out of the way as needed. In some instances, this can be more easily accom-plished if some of the plastic cable ties are re-moved with a diagonal cutter. A supply of extra ties is included with the spare parts kits.
When installing an assembly, make certain that the spacers are held to the PC boards with their re-tainers as shown in Figure 6. Tighten all mount-ing screws firmly since grounding between the cir-cuit patterns and chassis is accomplished through the stand-offs.

PC ASSEMBLY REPAIR GENERAL
Four servicing aids are given below to assist in the repair of defective assemblies. They are:

1. A table listing the various circuit functions, the assembly on which they are located and the principal semiconductors and components that re-late to their operation;
2. A complete set of schematic drawings for all PC assemblies;
3. Semiconductor termination drawings;
4. A list of unique parts used on the assemblies and main chas-sis with schematic symbols and TEN-TEC part num-bers.

RECEIVE FUNCTIONS
FUNCTION ASSEMBLY /SCHEMATIC COMPONENTS

TRANSMIT FUNCTIONS
FUNCTION ASSEMBLY /SCHEMATIC COMPONENTS

TRANSMIT AND RECEIVE FUNCTIONS
FUNCTION ASSEMBLY /SCHEMATIC COMPONENTS

SPECIAL PARTS LIST

The list below contains all components used in the Model 150 Transceiver that are unique to it and not readily available except from TEN-TEC, Inc.
It includes all transistors, diodes and integrated circuits, special trimmer capacitors a n d potentio~ meters, inductances and rf transformers, special panel controls a n d  switches a n d some hardware items such as knobs, e t c . Not included are c o m ~ ponents that are easily procured such as small fixed resistors, film, ceramic a n d  lectrolytic capacitors and miscellaneous hardware. The list is grouped into the various PC assemblies and the main chassis and contains a description, part number and symbol  used i n the schematic draw- ing for easy reference.
TEN-TEC, Inc. offers t h e listed items as well as complete PC assemblies, metal parts and hardware items in four Spare Parts Kits. Contact your rep- resentative or TEN- TEC directly for kit details.

SPECIAL NOTICE
This Model 150 Transceiver is equipped with an electronic circuit breaker instead of the mechani- tal type that was previously used. The componentsare mounted on a small  printed circuit board that is affixed to the ON/OFF switch. The entire unit mounts in the panel by means of the ON/OFF switch. In addition to the two red positive leads  that were connected to the mechanical type breaker, an additional smali ground lead is required between the PC board and chassis.
In operation the breaker is reset after tripping by cycling the switch to the OFF position and then back to the ON pesition. If the switch is left in then ON position and the  source +12 volt line is Opened, reapplying the +tDC voltage WILL NOT reset the breaker. It will be necessary to cycle the ON/ OFF switch to bring the transceiver into  opera~ tion. The power-on condition is evidenced by illu~ mination of the panel meter. The breaker is designed to trip between 22 and 28 amperes with applied voltages  between 11 and 14 volts DC. If the source voltage drops below 11 volts, the trip-out level will be reduced below 22 amperes. (If source voltage is sufficiently low, ON/OFF function will be disabled.) Tf the breaker repeatedly trips after resetting, check these possible causes:

1. If breaker trips only after speaking into mi- crophone, check antenna system for short cir~ cuit or high SWR.
2. If breaker trips only after speaking into mi~ crophone, check for low DC source voltage.
3. If breaker trips immediately after resetting, check for defective RF final amplifier, Pt.No. BO998/B0575.

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