ALINCO DR-1200T Mobile VHF Transceiver Instruction Manual

May 15, 2024
ALINCO

DATARADIO
DR-1200T
INSTRUCTION MANUALALINCO DR 1200T Mobile VHF
TransceiverAllNCO ELECTRONICS INC.

INTRODUCTION

Thank you for purchasing the Alinco DR-1200T (US Model).
Alinco radios and other products are ranked as some of the finest in the world.
Your DR-1200T has been manufactured and tested very carefully at the factory and will give you satisfactory operation for many years. We are confident that you will be very satisfied with your choice of this fine ALINCO radio.

ACCESSORIES

Carefully unpack your transceiver and you will find the standard accessories included:
Standard Accessories

  • DC Power Cable
  • Interface Cable

Optional Accessories

  • Mobile Bracket
  • Mobile Bracket Mounting Hardware
  • Microphone for DR-1200T
  • 4 pcs. of rubber foot

SPECIFICATIONS

General

Frequency Coverage| 144.0 – 148.0 MHz
Antenna Impedance| 50 ohm unbalanced
Power Requirements| 13.8 volts D.C.
Receive Current| 0.5 ampere (approx.)
Transmit Current| 5.5 ampere (approx.)
Dimensions| 5 1/2 x 2 x 6 3/4 Inches
Weight| 2.25 lbs.
Transmitter
Output Power| 25 watts
Emission Mode| 16F3
Modulation Type| Variable Reactance (True FM)
Maximum Frequency Deviation| ± 5 kHz
Spurious Emission| Better than – 60 dB
Receiver
Receiver Type| Dual Conversion, Super Het.
Modulation Acceptance| 16F3
Intermediate Frequency| 10.7 MHz and 455 kHz
Sensitivity| 12 dB SINAD less than 0.16 µV
Selectivity| Better than ± 6kHz at the – 6 dB points.
Less than ± 12 kHz at the – 60 dB points.
Audio Frequency Output| 2 watts into 8 ohm @ less than 10 % distortion.
Speaker Impedance| 8 ohm

(For Ham Bands Only) Specifications and features are subject to change without notice or obligation.

OPERATION

**CONTROL FUNCTIONS

**

Front Panel

ALINCO DR 1200T Mobile VHF Transceiver - Front Panel

  1. Main Dial
    Main dial is used to select the transmiVreceive frequency, Mem­ ory Channel, Frequency Step, Tone Frequency, and Offset Frequency.

  2. Display Panel
    The LCD displays operation in­ formation such as transmiVreceive frequencies. memory channel in­ formations, offset, tone frequency etc. See page 6 for additional in­ formation.

  3. VOL (Volume) Control
    Turn the control clockwise to increase the volume, and turn it counterclockwise to decrease the volume.

  4. SQL (Squelch) Control
    The SOL control is used to elimin­ ate noise during no signal periods. Normally this control is adjusted clockwise until the noise just dis­appears, and the BUSY indicator goes off. (Threshold level)

  5. H/L (High/Low) Switch
    This switch is used to select the desired transmitter output power level.

  6. Power Switch
    Press to turn on. Press again to turn off.
    Function Keys (7 through 15)
    NOTE: Commands underlined indi­cated in Blue on transceiver keys.

  7. F (Function) Key
    This is used to access secondary controlling function rrbeled in blue. i.e. MW, CH.SP, LOCK, BEEP SKIP, and CALL W. See Function Operation pages 8-10. MW is used with the F key to store data in memory. See Memory Pages 9-10.

  8. MHz key
    The MHz key is used to change the frequency up or down in one MHz steps.
    Press the MHz key, and the decimal point and kHz digits will disappear from the display. The frequency in MHz will be changed by rotating the nam dial or pressing the UP/DOWN buttons· on the microphone. Press the MHz key again or the PTI switch to return the display to the complete frequency readout.

  9. VFO/M (VFO/MEMORY) key
    VFO/M is used to select VFO or Memory mode.
    Press the VFO/M key to alternate between VFO and the Memory Channel mode.
    CH.SP is used with the F key to select frequency steps for program­ming and scanning. See page 8.

  10. REV (Reverse) key
    REV is used to invert the TX and RX frequency in Repeater mode. LOCK is used with the F key to disable the Function keys. See page 8.

  11. SHIFT key
    The SHIFT key is used to select the desired transmitter offset during re­peater operation. When the key is pressed, the offset mode cycles from – to

  • to Dual to Simplex.

    1. TONE key (CTCSS key)
      The TONE key is used to:
      A. Activate the Tone frequency selection process. See page 12.
      B. Enable/Disable the Encode/Decode functions. See page 12.
      The BEEP key is used with the F key to Enable/Disable the function confirmation tone. See page 8.

    2. PAI (Priority) key
      The PAI key is used to control Priority function. See pages 11-12.

    3. SCAN key
      The SCAN key is used to activate the frequency scan and memory scan functions. See pages 10-11. The SKIP key is used with the F key to skip busy memory frequencies when scanning. See page 8.

    4. CALL key
      The CALL key is used to bring Memory Channel “C” to the display. See page 9. The CALL W is used to enter frequency into memory channel “C”. See page 9.

    5. Microphone Connector
      Plug the interface cable into this jack

ALINCO DR 1200T Mobile VHF Transceiver - Microwphone
Connector

Display

ALINCO DR 1200T Mobile VHF Transceiver - Connector

  1. REV (Reverse) Indicator
    Turns on when the reverse function has been selected.

  2. Shift and Dual indicators
    “+” or .. – ” indicator turns on during repeater offset operations. See page

  3. “DUAL” indicator turns on during Dual operation. See page 14.

  4. ENC (Encoder) indicator
    Turns on to indicate that ENCOD­ ING TONE function is active.

  5. DEC (Decoder) indicator
    Turns on to indicate the DECODER (CTCSS} function is active.

  6. PRI (Priority) Indicator
    Turns on to indicate the PRIORITY function is active.

  7. CALL Indicator
    Turns on to indicate the CALL func­tion is active.

  8. Frequency display
    Displays the transmiVreceive fre­quency, Frequency Step, or Tone Frequency.

  9. Decimal point indicator
    Separates the MHz, and kHz. Flashes in Scan mode. Disappears in Memory skip mode.

  10. BUSY indicator
    On whenever the squelch is open or signal is received.

  11. S/RF Meter
    This meter indicates the relative receive input signal strength and relative transmitter RF output.

  12. ON AIR indicator
    Turns on during transmit opera­tions.

  13. M (Memory) indicator
    Turns on whenever the transceiver is in the Memory mode. Flashes to indicate programming in process.

  14. Memory Channel Number display
    Indicates the selected memory Channel Number.

REAR PANEL

ALINCO DR 1200T Mobile VHF Transceiver - Rear Panel

  1. Antenna Connector
    Used to connect the antenna to the set.
    Use a PL259 antenna-plug with 50 ohm impedance.

  2. Power Connector
    Connect the supplied power cable to this connector.

  3. External Speaker Jack
    When an external speaker (Imp.: 8 ohm) is used, connect it to this jack.

FUNCTION Operation

Whenever the F key is pressed, the “M” indicator will flash. You must com­ plete the desired programming within 5 seconds, or the indicator goes off or stops flashing. In that case. you must press the F key again.
The F key is used with secondary functions printed in blue on the trans­ ceiver function keys.

  1. Frequency Step Selection
    The frequency step can be selected by using the following procedure:
    A. Press the VFO/M key to select the VFO mode.
    B. Press the F key and then press the CH.SP key.
    C. Select the desired frequency step using the Main Dial (or the icrophone UP/DOWN but­tons.) The example below shows the order. in which the Main Dial (or UP/DOWN but­tons) will increase or decrease the spacing. D. Press the F key again or PTT switch to return to VFO mode.

  2. Key Lock
    A. Press the F key, and then press the Lock key.
    B. The “L” indicator will replace the Memory number shown on right side of display.
    C. Stops all function keys except the PTI switch.
    D. To cancel this function, press the F key and the LOCK ke) again.

  3. BEEP ON/OFF
    A. Press the F key, and then press the BEEP key.
    B. Repeating this procedure, beep will turn ON and OFF alter­nately.

  4. Memory Skip
    The Memory Channel Skip function allows you to temporarily skip un­ wanted Memory Channels during Memory Channel Scanning.
    A. Press the VFO/M key to select the Memory Channel mode.
    B. Select the Memory Channel that you want to skip using the Main Dial. (or the microphone UP/DOWN buttons.) Press F key, and then press the SKIP key. The decimal point between MHz and kHz will dis­ appear from the display.
    C. A frequency in memory without the decimal point will be skip­ped when scanning memories.
    D. To cancel Memory Channel Skip, press the F key and the SKIP key again.

  5. CALL Channel Entry
    A. Select VFO mode by pressing the VFO/M key.
    B. Select the desired operating band and frequency.
    C. Press the F key, and then press the CALL W.
    D. When the CALL Wis pressed, the frequency shown on the LCD will be stored into memory “C”.
    E. Whenever CALL is pressed, Memory “C” will come to the display.
    F. To Change from CALL mode back lo VFO or Memory, press the VFO/M key.

  6. MEMORY
    A lithium battery is installed to retain memory in the transceiver. Turning off the POWER switch, disconnecting power cable, or a power failure will not erase mem­ ory. The battery should last for approximately 5 years.
    • Microprocessor Initialization
    When you want to erase all pro­grammed data, or ii the display should show erroneous informa­tion, you should reset (initialize) the microprocessor using the fol­owing procedure:
    1. Press and hold the F key and the VFO/M key at same time. and turn off the POWER switch. Now turn the POWER switch on again, while still holding buttons depressed.
    2. Release the buttons-Factory programming is now in place.
    • Memory Channel
    This transceiver has 14 memory channels (1-9, A-E). In addition to serving as normal memory channels, some serve a dual pur­ pose. The functions of the Mem­ ory Channels A-0 are described below.
    A. Memory Channels A and Bare used to store the Frequen­cy limits for the Program Scan Function. For additional in­formation, see Band Scan on page 11.
    B. Memory Channel C is used to store the CALL channel fre­quency.
    C. Memory Channel D is used to store the transmit frequency used for odd offset operation.
    • Memory Channel Contents
    Each Memory Channel is capable of storing:
    Frequency
    SHIFT status (Offset)
    TONE status, (Encode. Decode, and Frequency)
    Receive Frequency for odd offset operation. See page 14.
    • Memory Entry
    1. Press the VFO/M key to select the VFO mode.
    2. Select the desired operating frequency.
    3. Activate sub audible tone if it is required.
    4. Press the F key. The “M” indicator will flash.
    5. Select the desired Memory Channel using the Main Dial (or the microphone UP/ DOWN buttons.)
    6. Press the MW key during the “M” indicator is flashing. If the flashing stops before the MW key is pressed, you must press F key again in order to complete the desired function.

SCAN

The following scan options are avail­ able:

Program Scan (Limited Frequency Coverage n one band only)  Memory Scan Band Scan
A. Programmable Scan
The scan frequency is determinec by the frequencies stored in Mem­ory Channels A and B. The frequency stored in Memory Channel A and B must be different frequencies.
Before pressing the SCAN key, adjust the SOL control to the threshold level.

  1. Determine the desired scan fre­quency range and enter the fre­ quencies into Memory Channel A and B.
  2. Press the VFO/M key to select the VFO mode, and also select the band of the stored frequen­cies.
  3. Press the SCAN key to nitiate scan.
  4. To clear scanning, press the SCAN key.

B. Memory Scan

  1. Press the VFO/M key to select 1″ the Memory Channel mode.
  2. Before pressing the SCAN key, adjust the SOL control to the threshold level.
  3. Press the SCAN key to initiate scan.
  4. To clear scanning, press the SCAN key.

C. Band Scan
This scan will proceed over the entire tuning range of band.

  1.  Press the VFO/M key to select the VFO mode.
  2. Store the same frequencies into Memory Channels A and B.
  3. Before pressing the SCAN key, adjust the SOL control to the threshold level.
  4. Press the SCAN key to initiate scan.
  5. To clear scanning, press the SCAN key.
    • The transceiver will stop on a busy channel until a signal drops.
    After a short delay the scan will resume.
    • If you want to resume scanning when the transceiver stops on a busy channel, rotate the Main Dial.

PRIORITY SCAN

The following Priority Scan options are available:
Memory Priority Scan
VFO Priority Scan
CALL Priority Scan

A. Memory Priority Scan

  1. Store the desired priority frequency into any Memory.
  2. Select VFO mode, and dial up the frequency you want to oper­ate on.
  3. Press the PAI key to initiate Memory Priority Scan. The transceiver will scan the Priority in Memory Chennel for 1 second out of 6 seconds and the VFO frequency for the remaining 5 seconds.
  4. When a signal is present on the Priority Memory Channel, press the PAI key, and then press the VFO/M key. The Priority scan will stop and the Memory Chan­ nel will come to the display.

B. VFO Priority Scan
This function is the reverse of Mem­ory Priority Scan.

  1. Select VFO mode, and dial up the frequency to be scanned.
  2. Select the desired Memory you want to operate on.
  3. Press the PAI key to initiate VFO Priority Scan.
  4. To cancel this scan, press the PAI key again.

C. CALL PRIORITY SCAN

  1. Store the desired frequency for operation in Memory Channel ”C”.
  2. Press the CALL key and then the PAI key.
  3. The tranceiver wilt scan the VFO for 1 second and the CALL Channel for 5 seconds alter­nately.

TONE FREQUENCY SELECTION

  1. To select a Tone (CTCSS) Frequen­ cy, press the VFO/M key and select the VFO mode, then press the TONE key. The display will indicate a Tone Frequency in Hz.
  2. Select the desired Tone Frequency using the Main Dial.
  3. This press also enables/disable Encode/Decode activation. There are 37 CTCSS Tone Fre­ quencies available as shown below.
  4. Press any key to return to the receiver frequency display. The subaudible tone will be while transmitting.

Subaudible Tone Chart

Hz Hz Hz Hz Hz Hz
67.0 85.4 107.2 131.8 162.2 203.5
71.9 88.5 110.9 136.5 167.9 210.7
74.4 91.5 114.8 141.3 173.8 218.1
77.0 94.8 118.8 146.2 179.9 225.7
79.7 100.0 123.0 151.4 1862. 233.6
82.5 103.5 127.3 156.7 192.8 241.8
250.3

TONE SQUELCH (CTCSS)

This function allows you to remain squelched until the proper Tone Fre­ quency is received. ti you are on a busy frequency. this can be quite and aid.

  1. Press the TONE key. The ”ENC” will appear on the display panel. Press the TONE key again. The “DEC” will appear next to the “ENC”.
  2. Your radio will now remain squel­ched until the proper code is re­ceived. You should ensure all stations. you wish to communicate with, use the same Tone Frequency.
  3. To release the Tone Squelch func­tion (Normal noise activate squelch), press the TONE key again. The “ENC” and “DEC” will disappear from the display.

REPEATER Operation

All amateur radio repeaters utilize a separate receiver and transmitter sec­ tion. The receiver frequency may be either above or below the transmitter frequency.
This transceiver allows you to store the frequency offset frequency (0.6, · 6, 5.0 and 7.6 MHz.) and offset direc-Channel ( 1 -9 and A-E). Jn in Memory To select the desired transmitter offset direction. press the SHIFT key. Each time you press the key. the radio will advance from one offset to the other. i.e. “-” to “+” to “Dual”. To select the desired transmitter offset. press the SHIFT key. and then rotate the Main Dial . Each time controls. the radio will advance through the following steps: “O” to “0.6” to” 1.6″ to “5” to “7.6”. After the offset has been stored, press any key, except the SHIFT key.
The normal display will re

REVERSE Function

The REV key has been provided to allow you to reverse the transmit and receive frequencies. To use the Re­ verse function, press the REV key. The REV indicator will light in the display to remind you that you are working a reverse repeater pair. To return to normal operation, press the REV key again.

TRANSMISSION

Caution

  1. Ensure that an antenna with a low standing wave ratio (SWR) is attached to the antenna connector before attempting to transmit. Fail­ure to provide proper termination may result in damage to the final amplifier section.
  2. Always check to ensure the fre­quency is clear before transmitting.

A. Simplex Operation

  1. Select the desired operating fre­quency using any of the methods described above.
  2. Send command to transmit from your TNC. The ON AIR indicator will be lit.

B. Odd Offset Operation
For other than 600 kHz. 1.6 MHz, 5.0 MHz and 7.6 MHz splits.

  1. Select Memory “d” in memory mode.
  2. Select VFO and dial up a transmit frequency required.
  3. Press the F key then press the MW key to store the transmit frequency into memory “d”.
  4. While still in VFO mode dial up a receive frequency.
  5. Press the SHIFT key to select ottset, continue to press until trans­ceiver cycles through +. – and Simplex to “Dual”.

DATARADIO OPERATION

FOREWORD

PACKET RADIO has propelled Amateur radio into the era of com­ puters with a quantum leap. Because of this rapid move into the world of digital communications, there are many new hams entering the hobby for the express purpose of using these dicital modes that make use of the Outputer and associated software. AS a result of this rapid growth, many of these new amateurs found that it would require the use of the FM mobile unit, or a second VHF tran­ sceiver to access the large variety of Packet applications that exist, includ­ ing; keyboard to keyboard networks, switches, nodes, DX spotting nets, BBSes, conference clusters, and much more enjoyment centered around the use of Packet radio. With many of these Packet systems, the user can connect to distant sta­ tions in other cities, states, and coun­ tries using low powered transceivers. There is no need for super powered transceivers that run hundreds of watts.
Packet Radio is a mode of communi­cations which makes use of a “store­ and- forward” technique called; AX.25 r … tocol. This format provides error through-put of both ASCII, and binary, text or data between stations that are connected using the AX.25 protocol.
ALINCO attends hamfests throughout the United States, and the world. One of the subjects that seem to be on the mind of many Packeteers is: Where can they find an economical tran­ sceiver that will function well when used in the digital, or Packet modes?
ALINCO LISTENED TO YOUR RE­ QUESTS, and ALINCO has respond­ ed with the kind of transceiver that is designed with the Packeteer in mind. First of all, the DR-1200T is engineered to provide optimum audio characteris­ tics for the Mark and Space tones of
1200 and 2200 Hz. By using this ap­ proach with both the transmit and receive circuits, the DR-1200T can be utilized with both 1200 and 2400 bps. The same high quality is built into the DR-1200T DataRadio as with all other ALINCO products, yet the cost of the DataRadio had to be considered, because for many Packet users this would be a second transceiver. In order to make the DR-1200T DataRadio more economical, the DR-1200T comes without a mobile mounting bracket, microphone, or accessories that are not needed in a Packet Radio environment. This does not mean the DataRadio is not suitable for use with FM voice operation.
As a matter of fact, the DR-1200T per­ forms well in voice applications. An accessory kit that includes the micro­ phone, and mobile mounting bracket is available as an option for the DR-1200T DataRadio.
INTERFACING YOUR ALINCO DR-1200 TO THE TNC
In an ettort to minimize the new DR-1200 DataRadio owners time put­ ting the station on the air, ALINCO is including the necessary interface cable with the transceiver connector already installed. This means that only the connector for the TNC end is needed to put the Packet station on the air. Many TNC manufacturers in­ clude the TNC connector as one of the supplied accessories.
Pin out connections for the DataRadio 1/0 connector are listed below. These connections are already wired and soldered at the DataRadio connector (female) end of the cable. The color coded wires identify the appropriate TNC signal connections.
Note:
If hum or noise is experienced on the transmitted packet signal, disconnect the shield connection at the TNC end of the cable. The gray wire at pin 8 will provide ground return for the PTT line, and no other ground are necessary. As an added benefit, ALINCO is supporting the new DR-1200 DataRadio owner by including some drawings that illustrate examples of how the DR-1200 is interfaced to many Packet R!3.dio, Terminal Node Controllers (TNC).
Before beginning the interface, and setup procedures that are discussed in the next portion of this manual, it is recommended that you read the ap­ pendices in the final section of this manual. This will familiarize you with the transceiver, and best of all you will discover the many wonderful features that are a part of your ALINCO DR-1200 DataRadio.
Packet Operation of the ALINCO DR-1200 DataRadio
Using the interface configuration for your TNC, connect the DR-1200 to the TNC. Your TNC should already be in­ terfaced to your Data Terminal Equip­ ment (DTE). The DTE can consist of a “dumb” terminal, or a computer with the appropriate terminal software loaded. The TNC should be configured for the correct hand-shaking between the computer/terminal, and the TNC. Most computers use “hardware” hand-shaking. If this is true in your sit­ uation, then set the TNC XFLOW to OFF. If you are using “software” hand­ shaking, then set the XFLO to ON. To begin operation of your Packet sta­ tion, there are other TNC parameters .which may need setting. As a rule tb= TNC manufacturer will supply t ) TNC with “DEFAULT” parameters which are acceptable. As you become familiar with your new station, and with the ALINCO DR-1200, you may determine that some adjustments of the TNC parameters are needed.
Before continuing; install your callsign into the TNC. At the command prompt (cmd:), enter your callsign in the fol­ lowing manner: MYCALL [Your Call) .< Enter>

DR-1200 PIN NUMBER WIRE COLOR TNC Function
1 YELLOW W/Black Sleeve AFSK OUTPUT
2 RED Push:ToTalk PTT Control
6 ORANGE Rx AF RECEIVE Audio
7 SHIELD Shield/Ground
8 GRAY Ground PTT Ground

Note:
Callsign installation may differ in some TNCs.
For openers we will set a few of the TNC parameters as follows:
TXDelay 30 to 40 (milliseconds)
TXD 35 is optimum for the DR-1200. In most applications, you may find that even faster TX Delay times are accept­ able. This is because the ALINCO DR-1200 DataRadio has a very rapid receive to transmit transition period.
The following parameters are sug­ gested, however, the TNC may have default parameters which can func­ tion without modification or change.
FRack 4 SCReenl O MCOM ON MCON OFF DWait 16 MRPT ON Still other TNC parameters can be set .Jit the users system, and mode of operation. It should be pointed out that these settings may also depend on the make and model of your termi­ nal, and in some cases, the software.
Ensure that an antenna, set for the VHF Packet portion of the band, is at­ tached to the DR-1200. Make sure the DR-1200 is on the packet frequency that you wish to use, and check the transceiver “shift” or offset to be sure it is set correct. Most Packet systems operate in the simplex mode, thus, there are no offsets and no “shifts” used.
If you are unable to contact a local Packet Users Group, or fellow pack­ eteer to assist with your first contact, then try one of the national throughput frequencies like 145.010 MHz.

■ NOMINAL SETTINGS
In tests we’ve run on many TNC’s, we’ve found that setting the volume control pointing to the left, or to 9:00 O’clock, will provide ample receive audio for decoding data by most TNC.
As you become familiar with the tran­ sceiver and TNC, you may observe that less receive audio is needed … or in a few instances, your TNC may require slightly more AF.
The squelch is set to a point where no noise (white/shot noise) is received through the speaker of the DR-1200T, or indicated by the DCD lamp on the TNC. Under normal operating condi­ tions, we’ve noticed that a setting of 12:00 O’clock is sufficient to  keep the noise subdued until a packet signal is present.
■ RECEIVING PACKET SIGNALS
Another way to set the volume and squelch with the TNC is to make all the correct interface connections, and with the system on and in the receive operating mode, turn the volume up about one fourth turn, or to about ten O’clock. Open the squelch by  turning it all the way counter-clockwise. until noise is heard. While watching the DCD, RCV, or CONV. LED (depending on the manufacturer) on the TNC. assuming the DCD lamp is illuminated, turn the volume control down until the DCD LED is no longer lit. Now slowly turn the volume control until it again il­ luminates. To be sure there is ample AF drive to the TNC, move the volume control slightly, more clockwise. This will ensure that enough audio is  present to provide optimum data decoding.
■ REMEMBER; TOO MUCH AUDIO IS AS BAD AS NOT ENOUGH!
Next turn the squelch up (clockwise) until the DCD LED extinguishes or goes off. As with the volume, close the squelch slightly more clockwis ) be sure there is a solid squeicn threshold.
If you are on a packet frequency, and there are packet signals present, your DR-1200T should be hearing the packet signals. If the terminal is connected and the TNC is properly configured, your station should be printing text on the screen or to the printer, if one is present.
■ TRANSMITTING PACKET
To operate (transmit) a packet station you should have a current amateur radio license that allows operating privileges within the spectrum that your DR-1200T is tuned to.
If the interface cables are properly wired and connected then we are ready to establish contact with another Packet station.
It is wise to solicit the help of anotl person who is already operating in the Packet modes. This way you will have someone who can listen for your sig­ nal ,and guide you into the operating frequencies that are used for Packet in you ares.
Although the ALINCO DR-1200T DataRadio is engineered to make use of limiting circuits that are designed to prevent over modulation (deviation), there are some TNCs which may drive the transmit audio circuitry too much.
An indication that a problem such as this is present, would be noticed when a connect is tried to a nearby Packet station with no results. Often too much transmit deviation can cause the same problem as not enough transmit audio. The best audio level Setting has been found to. be in the large of 3.5 kHz to 4.5 kHz swing.
All TNC,without exception, have provi­ sions within their circuitry that allows the user to increase, or decrease the AFSK level(s) when necessary. It is advisable to have knowledge of which component inside the TNC, controls the audio output as it may be neces­ sary to make an adjustment to the associated level control(s).
Remember; this is the exception, and not the rule, less than 20 percent of all TNCs will require any adjustment at all.
■ ADDITIONAL INFORMATION
To turn off audio signal from a speaker, you can plug dummy load as below.

INTERFACE CABLE

ALINCO DR 1200T Mobile VHF Transceiver - Interface
Cable Remarks: The number of cables are five and 3 . 4 , 5 are un-useful.

■ CONNECTION SAMPLES FOR PACKETS![ALINCO DR 1200T Mobile VHF Transceiver

Documents / Resources

| ALINCO DR-1200T Mobile VHF Transceiver [pdf] Instruction Manual
DR-1200T Mobile VHF Transceiver, DR-1200T, Mobile VHF Transceiver, VHF Transceiver, Transceiver
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