Four State QRP Group Bayou Jumper 40 Meter CW Transceiver Instruction Manual
- June 10, 2024
- Four State QRP Group
Table of Contents
Bayou Jumper 40 Meter CW Transceiver
Assembly & Instruction Manual
Bayou Jumper 40 Meter CW Transceiver
For revB (Blue Panel) kits shipped after 1 Jan 2021 Copyright 2017, 2020
David Cripe NM0S Jim Giammanco N5IB
&
Four State QRP Group
ACØBQ photo
PLEASE READ THIS ENTIRE MANUAL BEFORE BEGINNING ASSEMBLY
Introduction
Thank you for purchasing a Bayou Jumper transceiver kit. We hope you will
enjoy building it and have many QSOs with it. This kit is comprised of
highquality components, a silkscreened, solder-masked, double-sided PC board
and front panel, and hardware for mounting in a wooden enclosure.
This kit owes its genesis to the imagination of Jim Giammanco, N5IB, who
envisioned this project in homage to the classic Paraset’ transceiver, http://www.paraset.nl/ the legendary spy radio from World War II. Using the same circuit architecture as the original, Jim brought it up to date with solidstate circuitry, giving the user an authentic feel of the original radio without the high voltages and scarce components of a tube circuit. Jim named his creation the Bayou Jumper after the popular KnightKit Ocean Hopper regenerative receiver that so many novice hams built a half-century ago, and with a salute to his Louisiana heritage. His presentation on the project was one of the most popular presentations at OzarkCon 2016. The Four- State QRP Group is proud to be able to present the Bayou Jumper to the QRP community. The transceiver is comprised of two separate circuits, a crystal-controlled transmitter and a regenerative receiver. The transmitter uses 4SQRP’s super simple, super robust NS-40 transmitter circuit, with trademark on-board spiral PCB trace inductors, and between 4 and 5 watts output power. The Bayou Jumper utilizes a regenerative receiver, the same as the original Paraset. No other receiver circuit provides the combination of sensitivity and selectivity with low parts count. Regenerative receivers were popular among hams for this reason. The receiver in the Bayou Jumper has been measured to have a Minimum Discernible Signal (MDS) of better than -120 dBm, which is as good as many commercial receivers. In the Bayou Jumper, the receiver tunes independently from the transmitter frequency, so there is a
Spotting’
function to allow the user to tune the receiver to the transmitter frequency.
Switching between transmit and receive is performed with a rotary switch, just
as was done with the original Paraset. You cannot get more simple and reliable
than that!
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The entire transceiver was designed to fit inside a standard wooden box, available from Hobby Lobby. It can be ordered here: http://www.hobbylobby.com /Crafts-Hobbies/Wood-Crafting/Unfinished-Wood/WoodRectangle-Box-Set-with- Silver-Handle/p/25426-GA0369 The on-line sale is for a set of three boxes, of which the smallest is used. The boxes can be purchased individually in stores, SKU# 662536S.
Theory of Operation
The Bayou Jumper, like the Paraset that inspired its creation, utilizes very simple and robust circuitry to achieve reliable operation. Despite this simplicity, it attains the maximum of performance from its minimum number of components, in the true spirit of QRP.
The transmitter design of the Bayou Jumper is borrowed from the 4SQRP classic `NS-40′. This design is a master-oscillator/power amplifier circuit, with high-efficiency spiral PCB coils serving as the transmitter’s harmonic filter. The 2N7000 Master Oscillator, Q5, works against the gate capacitance of the IRF510 power amplifier, Q4, as an unusual inverted Colpitts oscillator. The power amplifier Q4 is tuned to operate in the Class E mode, generating 5 watts from 13.6 volts, at better than 85% efficiency. Closing the key contact grounds the source circuits of Q4 and Q5 permitting oscillation to commence. If the transmit/receive switch is in the receive position, closing the key permits the Master Oscillator to oscillate without the PA operating, enabling spotting of the oscillator frequency in the receiver.
A built-in key is included in the design just like in the original Paraset!
Because the entire PA current passes through the keying circuit, it is
recommended, for those who want an external key, that the transmitter be keyed
through a hard contact closure, like a relay or straight key, or that a husky
MOSFET (IRF510 or larger) be used. See APPENDIX J for suggested circuits.
The receiver is a simple regenerative circuit, based on the innovative designs of Charles Kitchin, N1TEV. Q2, an MPF102 JFET, is a regenerative detector in an Armstrong circuit, with a 1N5819 diode acting as a varactor capacitor in the tickler throttle circuit. The regeneration control, potentiometer R10, varies the reverse bias voltage on the diode D2, changing its capacitance and varying the amount of feedback current it passes through the tickler feedback winding of L1.
The receiver frequency is tuned by also using a reverse biased diode as a
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varactor. The inductor L1 resonates against the sum capacitance of C20,
(optionally C20a) C30, and diode D3. Tuning is performed by potentiometer R8,
which varies the reverse bias voltage on D3, thus varying its capacitance.
The antenna is coupled to the detector through the grounded-base amplifier Q1,
a 2N3904. This amplifier also isolates detector oscillations, preventing them
from being radiated back through the antenna. An RF attenuator control, R1,
can be used to reduce the amplitude of strong signals that might overload the
receiver.
The detected audio appears at the source of the regenerative detector Q2, and
is coupled though capacitor C5 to audio preamplifier Q3, a 2N3904. Its output
is coupled to the volume control R6.
The output of the volume pot is amplified by the Audio Amplifier U1. This IC,
an NJM2113 is a low-noise headphone driver amplifier. Its balanced output
feeds the tip and ring contacts of the Headphone jack, J4. The shell contact
is left floating, placing the two headphone elements in series. This amplifier
is also capable of driving an external 8 ohm speaker.
A 6-volt regulator IC, U2, provides steady bias voltage to the low-level RF
and audio circuitry of the receiver, eliminating any tendency toward audio
howl or instability.
Switching between transmit and receive operation is performed with a rotary
switch SW1. This disables the receiver during transmit, and switches the
antenna between the transmitter and receiver sections. This switch also has an
OFF position, switching the antenna input to ground as well.
First Steps
Before getting started with building the kit, take some time to organize and
familiarize yourself with the parts provided and check them against the Bill
of Materials (pages 34 & 35). Building over a cookie sheet is recommended to
minimize the chance of lost parts. If parts are missing in your kit, send an
email to the kitter listed at 4SQRP.com. He will promptly provide
replacements.
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Schematics are provided separately as image files in the documentation
package, as well as being incorporated into this manual. It is highly
recommended that you print a couple of copies at 11 X 17 inch format at your
local UPS Store, Staples, etc. As you build, use a highlighter to mark off
parts that have been soldered onto the PCB on one copy. When you think you are
done, you can check that copy to verify that all of the parts have been
installed.
It is helpful to acquire the necessary tools and supplies before beginning.
These include:
Soldering iron ESD safe, 20-30W, preferably thermostatically controlled. Small diameter (0.025″ recommended) 60/40 or 63/37 rosin core solder Wire stripper X-Acto type hobby knife (#11 blade best) Diagonal cutters (flush-cutting type preferred) Needle-nose pliers Fine file or emery board Phillips screwdriver Allen wrench: 1.5mm for the pointer knob’s set screw Hand drill with 1/8″ bit Non-metallic alignment tool Fine jeweler’s screwdrivers Electrical tape Clear fingernail polish Wood glue Clamps or spring clothespins Magnifier Digital volt-ohm-meter *Calibrated general coverage receiver, 40M CW receiver, or frequency
counter
Soldering is not hard if the proper procedure is followed. The soldering iron
is to be used to heat up the PC pad and component lead, and the solder applied
to the pad, where it melts and flows into the hole. Do not melt the solder
onto the tip of the iron and then attempt to dab it onto the joint a
defective connection will result! After soldering, check the top (component
side) of the board, to be sure the solder has filled the hole completely, and
wicked up around the component lead. Re-heat and apply more solder if
necessary.
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Enclosure
It would be best to prepare the enclosure before beginning assembly of the PC
boards, in case any minor sanding or filing were to be needed to refine the
fit of the boards into the box.
The enclosure must be prepared to mount the circuit boards. Included in the
kit are four 3/8″ wooden blocks that must be glued into the four inside
corners of the box. Use wood glue to attach them (Elmer’s Carpenter’s Wood
Glue the yellow kind). They should be spaced down from the rim of the box by
the thickness of two PC boards (about 1/8″) use the two crystal adapter
boards as a thickness gauge.
After the glue has dried for several hours, place the top panel circuit board
onto the four corner blocks. Use a pencil to mark through the four corner
holes in the top panel board onto the corner blocks. Remove the top panel.
There are four wood screws in the parts kit for mounting the circuit board
assembly. If driven directly into the corner blocks, there is a risk the
blocks will split, so it is necessary to drill pilot holes for the mounting
screws. Use a 1/8″ bit in a hand drill (or drill press if available), drill
down approximately 1/2″.
Solder Filling Selected Vias
Vias are small plated-through holes that electrically join the top and bottom
copper layers of the circuit board. If you look closely at the heavy traces
near D1 and C22 you’ll see two groups of four vias in the middle of those
traces. These traces, and vias, carry the full transmitter current a
substantial fraction of an ampere. To ensure a low resistance path these eight
vias should be filled, that is, enough solder should be flowed into them that
the solder is level with the via pads on both the top and bottom sides. The
same should be done to the vias at the center of each of the etched inductors.
Fill the four vias in the heavy trace near D1
Fill the four vias in the heavy trace near C22
Fill the three vias in the centers of the three etched inductors L3, L5, and L6
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Preliminary Assembly
The large components (four potentiometers, BNC jack, and rotary switch) will
be installed first. In order to ensure that these components properly line up
with the holes in the front
panel, test fittings will be performed.
Locate the six 5/8″ hex standoffs and twelve of the 6-32 x 3/8″ machine
screws. Use six of the screws to install standoffs on the bottom side of the
Front Panel PCB at the six perimeter mounting holes (NOT the four corner
holes).
The first components to be installed on the Main PC board will be the four
potentiometers. R6, R8 and R10 are 50 k pots, marked “503” while R1 is a 5 k
pot, marked “502.” All four of these potentiometers will be installed
“standing proud” to ensure that there is enough shaft above the panel to
accept the knobs securely.
Place the main PC board flat, right side up, on a hard
work surface, and insert the mounting tabs and pins of R8 (50 k, marked “503”)
through the PCB mounting holes so that the tips of the two tabs rest flush
against the work surface without extending past the bottom of the board. This
ensures that the shaft of the pot sits as high as possible.
Notice that when the two mounting tabs are flush with the bottom of the board,
the three contact pins will not quite penetrate all the way to the bottom.
This is normal and correct. The holes are through-plated, and when soldered
the connections will be solid.
Make sure the pot shaft is vertical, and then solder only
one of the mounting tabs to the board. It will be easiest to solder on the top
side of the board.
Place the front panel with its standoffs in position atop
the main PCB. Use three screws to temporarily secure the panel to the main
board. Inspect the alignment of R8 and make sure that the shaft can turn
easily without rubbing the sides of the hole. If needed, reheat the soldered
tab and reposition the part.
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Remove the front panel and set it aside for the moment. Do not yet solder
the remaining tab and pins.
Repeat the above two steps for the other two 50 k pots, R10 and R6
(marked “B5 03”), and the 5 k pot, R1 (marked “B5 02”). Again, solder only one
tab of each part at this time. Check the alignment of each one by temporarily
replacing the front panel each time.
When all four potentiometers have been partially installed, replace the front
panel. Secure it with all six screws, and make a final check of the alignment.
When you are satisfied with the positioning, remove the front panel and solder
the remaining tab as well as the three pins of each part.
Next the rotary switch and the BNC jack will be installed. Alignment of these parts will be much more straightforward, since they will be firmly seated against the PCB and should “auto align.”
You may wish to read the section in Appendix A concerning shortening the shaft
of the rotary switch. It’s only for appearance sake, to allow the knob to
nestle down close to the panel. If you decide to do this optional step, it is
most easily accomplished before the switch is
soldered to the board.
(optional) The shaft of the rotary switch is too long
Index post
to allow the selector knob to mount close enough to the
panel. Trim a bit off, but be sure that there is least ¼” of the shaft
remaining.
The plastic index post is not needed and will
interfere with the front panel mounting. Nip it off with
diagonal cutters.
Pin 1
Install the rotary switch SW1. Be sure the nut on
the bushing is snugged up against the toothed lock washer. Do not over tighten. Be certain that Pin 1 is inserted into the square pad marked “1”. The pin numbers are molded into the switch body. Make sure the switch is fully seated against the PCB and the shaft is vertical. Solder only one of the four inside pins at this time.
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Install the BNC jack in its location at the upper left corner of the PCB. Be
sure it is flat and flush against the board and is vertical. Solder only the
center pin at this time.
Re-install the front panel and make another alignment check. Locate the
“chicken head” pointer knob and install it on the rotary switch’s shaft.
You’ll need a 1.5 mm Allen wrench to tighten the set screw. Check that the
pointer will align with the panel markings for the three switch positions. If
all is satisfactory, remove the knob and panel and set them aside. You may
leave the standoffs in position if you wish.
Now solder all of the remaining pins of the BNC jack and rotary switch.
The leads of resistors and axial leaded inductors should be bent in a gentle radius about 0.1″ from the body of the part, so that the component body is not stressed or broken. If you have a bending jig, use it, selecting 0.4″ spacing for all ¼ W resistors and diodes, 0.5″ for L4, and 0.6″ for L2. The bodies of these components should rest flush against the board surface when mounted.
Inductors
There are two molded inductors that look a lot like resistors. Add these next. Be especially careful when bending the leads of these parts. Notice the relative sizes in the photo. The one with the larger inductance (L4 470µH) is the smaller physical size and may have either a brown or green body.
L4: 470 µH L2: 1 µH
Ref Value
Marking
Description
L2
1.0 µH Wide Silver-Brown-Gold-Black-Silver Molded Axial Choke .6″ LS
L4 470 µH Wide Silver-Yellow-Violet-Brown-Silver Molded Axial Choke .5″ LS
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Special note for builders who intend to install a NA1MH Soup’er Up’er
accessory board that is described in Appendix J. That accessory is not
currently available, but “previously owned” units may show up from time to
time.
You may wish to just tack solder R9 and C9 to the board in the upcoming steps,
leaving extra long lead lengths, since these parts will be subsequently
removed after the basic checkout of the Bayou Jumper, prior to installation of
the Soup’er Up’er. Leave enough lead that they can be easily nipped off and
salvaged for the spare parts bin.
Resistors Next, install these resistors, whose lead spacings may all be prepared as 0.4″. Save a few of the discarded leads for use as test points and jumpers later on.
Ref
R16 R17 R2 R4 R15 R3 R12 R7 R13 R5 R11 R9 R14 R18
Value
100 1.0 k 1.0 M 1.0 M 100 k 2.7 k 3.3 k 3.3 k 330 k 33 k 470 k 470 k 470 k 470
k
Marking
Brown-black-brown Brown-black-red
Brown-black-green Brown-black-green Brown-black-yellow
Red-violet-red Orange-orange-red Orange-orange-red Orange-orange-yellow
Orange-orange-orange Yellow-violet-yellow Yellow-violet-yellow Yellow-violet-
yellow Yellow-violet-yellow
Description
¼ W 5% axial ¼ W 5% axial ¼ W 5% axial ¼ W 5% axial ¼ W 5% axial ¼ W 5% axial
1/4 W or 1/8 W, 5% axial 1/4 W or 1/8 W, 5% axial ¼ W 5% axial ¼ W 5% axial ¼
W 5% axial ¼ W 5% axial ¼ W 5% axial ¼ W 5% axial
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Semiconductors
Identify and install the following components. Be certain that their polarity is correct, and that they match the board’s silkscreened outlines.
It is not necessary to secure the TO-220 parts to the PCB, but you may safely do so if you wish (4-40 machine screw & nut – hardware not supplied with kit). No insulating film is required beneath the part.
Note: The band on the silk screen outline for D1 may be partially obscured by several vias. The banded end of D1 should be oriented towards L6. You may wish to elevate the body of D1 very slightly above the board so that it is clear of those solder-filled vias.
Ref Value
Description
D1 1N5819 Schottky Diode (rectifier)
2N3904
MPF102
D2 1N5819 Schottky Diode (varactor) D3 1N5819 Schottky Diode (varactor) Q1 2N3904 TO-92 NPN BJT rf amp
C E B
G D S
Q3 2N3904 TO-92 NPN BJT af amp
Q5 2N7000
Static sensitive part *
TO-92 N-Channel Enhancement Mode MOSFET (oscillator)
Q4 IRF510
Static sensitive part *
TO-220 N-Channel Enhancement Mode Power MOSFET (PA)
Q6 IRF510
Static sensitive part *
TO-220 N-Channel Enhancement Mode
Power MOSFET
2N7000
78L06
D
IN
S G
OUT GND
IRF510
Q2 MPF102
TO-92 N-Channel JFET (regen detector)
U1 NJM2113
DIP-8 Audio Amp
- Touch a grounded object before
U2 78L06
Use supplied socket TO-92
handling static sensitive parts. Be sure your soldering tools are grounded or are rated ESD safe
6 Volt Positive Regulator
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Capacitors
The ceramic monolithic capacitors used throughout the kit are small and their
markings not always easy to read. Use a magnifier to verify their values
before installing. BE VERY SURE THAT THE 120 pF CAP GOES IN C20
Electrolytic capacitors must be installed with the correct polarity. The cases are marked to indicate the negative terminal, which goes into the round pad on the board. The longer lead is the positive lead, which goes into the square pad. Install these capacitors, solder and trim the leads. Check off each part as you install it.
Do not install C31 or C20a at this time.
Ref
C8 C14 C15 C28 C1 C2 C11 C17 C24 C5 C7 C19 C25 C27 C29 C32 C10 C4 C18 C26 C20
X C20a
X
C31
C16
Value
0.001 µF 0.001 µF 0.001 µF 0.0033 µF 0.01 µF 0.01 µF 0.01 µF 0.01 µF 0.033 µF
0.1 µF 0.1 µF 0.1 µF 0.1 µF 0.1 µF 0.1 µF 0.1 µF 1.0 µF 100 pF 100 pF 100 pF
120 pF
10 pF 22 pF
220 pF
Marking
Type
102
Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing
102
Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing
102
Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing
332
Dipped Monolithic Ceramic NP0, blue body, 0.1″ lead spacing
103
Ceramic Disk, red body, 0.1″ lead spacing
103
Ceramic Disk, red body, 0.1″ lead spacing
103
Ceramic Disk, red body, 0.1″ lead spacing
103
Ceramic Disk, red body, 0.1″ lead spacing
333
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing
104 1 uF
Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is +
101
Dipped Monolithic Ceramic NP0, blue body, 0.1″ lead spacing
101
Dipped Monolithic Ceramic NP0, blue body, 0.1″ lead spacing
101
Dipped Monolithic Ceramic NP0, blue body, 0.1″ lead spacing
121
Dipped Monolithic Ceramic NP0, blue body, 0.1″ lead spacing
Reform the leads to match the 0.2″ spaced pads
10
Dipped Ceramic Monolithic NP0 not supplied with kit, see page 23
22J, 22, or 220 Dipped Monolithic Ceramic, tan body, 0.1″ lead spacing DO NOT INSTALL YET
221
Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing
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C23
C3
C6
C9
C13
C22
C12
X
C33
390 pF 4.7 µF 4.7 µF 4.7 µF 4.7 µF 470 pF 47 µF
TBD
391 4.7 uF 4.7 uF 4.7 uF 4.7 uF
471 47 uF TBD
Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is + Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is + Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is + Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is + Dipped Monolithic Ceramic NP0, blue body, 0.2″ lead spacing Aluminum Electrolytic, 0.1″ lead spacing, observe polarity, longer lead is + Optional not supplied with kit see Appendix F
Bottom Side Components
Install C21 and C30, the two pink trimmer capacitors (20 pF). These mount on the bottom side of the board, soldered on the top side.
Notice the case has a flat side. Orient the flat side to match the outline on the component silkscreen on the bottom of the board, as in the photo at right. This ensures the adjusting screw is grounded, to minimize interaction with an adjustment tool.
Preset both trimmers to maximum capacitance maximum as shown in the photo at
left (use a magnifier).
capacitance
Ref Value C21 4-20 pF
C30 4-20 pF
Description Trimmer Capacitor (pink) Trimmer Capacitor (pink)
Transformer
Next, wind the toroid L1. It contains three separate, independent windings.
During the alignment of the receiver, to set the tuning range and regeneration control span, you may need to squeeze together or spread out the turns of the main winding and/or the tickler winding.
To make this process easier it is recommended that you install the toroid on the bottom side of the PCB. This would allow adjustment of the trimmer capacitors and the toroid’s windings to be accomplished without having to remove the front panel. The silkscreen outline is duplicated on the bottom to assist you. Actual performance of the receiver is not impacted whichever you choose. Do not be concerned that it appears the windings of a bottom mounted toroid would be in the opposite directions. It is only the relative direction of the windings that matters. Notice that each winding has one turn that is labeled with an arrow. This is the end from which the winding begins, coming up from the PCB, passing over the top and down through the center of the core.
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It is essential that this inductor be wound properly with the correct number of turns, the proper winding direction, and location. By following the diagram on the PCB silkscreen successful construction can be assured. For additional help with winding, read the notes at http://wa0itp.com/toroidophobia.html
An additional tip often the first couple of turns are difficult to get pulled up snug against the core, so wind two extra turns, and when that’s done, unwind the first two turns, leaving a nice tight winding.
Once you have decided on which side to install the toroid, refer to the photos below as a guide to winding the turns in the correct directions. Don’t worry if the numbers of turns in the photos below differ from these instructions it’s the direction that matters.
Locate the toroid core, and the 24 AWG magnet
wire. Wind the main tuning coil: Wind 19 turns (19 are pictured). Remember: turns are counted as the number of times the wire passes through the center of the toroid. It is essential that the turns are pulled snugly around the toroid, so that there is no slack between the wire and core. When complete, cut the wire ends to about 1/2″.
tickler Next wind the tickler. Wind
4 turns (4 pictured) of 24 AWG
main
magnet wire for the tickler input
tuning
winding. Cut the wire ends to
about 1/2″.
tickler
Finally, wind the input link.
L1, shown wound for, and mounted on, the bottom side
Wind 2 turns (2 pictured) of of the circuit board
AWG 24. Cut the wire ends to about 1/2″.
main tuning
input
L1, shown wound for, and mounted on, the top side of the circuit board
Strip and tin each of these wire ends prior to
inserting on the PC board. Then pull the leads up snugly and solder them in
place.
There are several methods for stripping the insulation from magnet wire. The wire provided in the kit is thermally strippable. With a higher wattage or thermostatically controlled soldering iron, the heat (at least 750 degrees F) will be sufficient to strip the insulation from the wire. Alternately, insulation may be removed using sandpaper or a sharp hobby knife, prior to tinning.
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Test and Instrument Connection Points
Provisions are made on the PC board to install
several wire loops that can be used to conveniently clip test instrument
leads. There are three groups of five pads (the middle pad is not used). Two
of the pad sets are grounded, and one set is connected to the +12 V supply.
Each set is identified on the silkscreen legend. Use discarded resistor leads,
forming them into loops. At each of the three groups of pads, install one loop
on the top of the board and one loop on the bottom. Solder the top side loop
on the bottom, and solder the bottom side loop on the top. Be sure that the
loop at the +12 V point will not be so tall as to interfere with the LED to be
installed underneath the front panel.
There are five places where single square post header pins are to be
installed.
At J7-7 and J7-9, as shown, insert the short end of a pin
down through the top of the board and solder at the bottom. A bit of masking
tape may help to keep the pin in position.
At V-reg, Rx-Vcc, and TP-1, insert the long end through
the board from the top, and solder on the bottom, as shown at right. This is
done because these are just test points, not connection pins for plug-in
wires, so a short test pin is OK.
Wire Jumper
Install a wire jumper, using a discarded resistor lead, at
JP1 (located near R8) on the top side of the PC board. Form the jumper into a
loop in the same manner as the test points. That way, should you at a later
date wish to open that jumper to install a modification, all that will be
necessary is to cut the loop and slightly separate the conductors.
Inspection prior to final assembly
Inspect the PC board closely for unsoldered connections, cold solder joints,
solder balls or splatter, improperly installed or incorrect components. Make corrections as necessary.
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Final Main Board Hardware
Add the contact post for the built-in key. This is a 3/8″
hex standoff. Install using a 3/8″ screw with at least two flat washers
between the standoff and the PCB. Two extra washers are provided in case the
key spacing needs to be adjusted to suit the builder.
Prepare the Molex® connector socket pin inserts to create the crystal
sockets. Take each of the inserts, and, using diagonal cutters, snip off the
bottom `fishtail’ as shown in the photos below.
Using fine-nose pliers or a crimping tool, gently squeeze the crimp area
marked on the photo until the pins are a snug fit into the holes in the board
for the crystal socket.
SQUEEZE
SQUEEZED
CUT
Level with top of PCB
Make certain each pin is vertical before soldering, and adjust as necessary to correct any misalignment.
Front Panel Components
Assemble the built-
in key. Locate the key
Key top side
Key bottom side
leaf spring. This is a
rectangular piece of
1/32″ plated PCB with
three holes. Install two 6-32x 3/8″ screws through the top of the front panel. On
the bottom of the board, slip the leaf spring over these screws, and mount using
two hex nuts on the bottom. Use a small drop of clear fingernail polish on the
end of the screws to keep the nuts from working back loose.
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Bayou Jumper revB Assembly Manual
page 15 of 47
Mount the key knob onto the leaf spring by inserting it through the top of the
front panel, and fixing it in place using the 8-32 brass screw from beneath.
Assemble the power jack. Very gently bend the
solder lugs of the power jack away from the body so that there will be sufficient clearance from the main board below. The lugs are fragile. A 90 degree bend may be too
Plus RED
much and could cause the lug to break. 45 degrees Minus should be enough. Strip 1/4″ from the ends of the 3″ red BLACK
and black stranded wires. Solder the red wire to the solder lug on the center
pin of the power jack, and the black wire to the lug connecting to the outer
shell of the jack. Use an ohmmeter if not sure which lug is which. Orient the
lugs with respect to the corner of the board, as shown in the photo, to minimize
the chance of an accidental short circuit.
A matching power plug is supplied. Wire up that 12 V power plug with your
choice of wire type and length so that 12 V can be applied to the circuit. A fused or current limited supply is recommended, at least for initial testing.
Mount the two 1/8″ stereo jacks to the front
panel by inserting them through the bottom, and fixing them in place using the
included knurled nuts. Cut three pieces of the 22 AWG bus wire, each
approximately 2″ long.
Ring terminal
Sleeve terminal not used
Onto the jack for the headphone output,
solder one piece of the bus wire to the solder lug for the tip contact and
another one to the ring contact.
Tip terminal
Stereo jack pin arrangement
Onto the jack for the external key, solder a single piece of bus wire to the
solder lug for the tip contact.
If not already in place, install the six 5/8″ hex standoffs to the top side of the
main PC board using the 6-32 x 3/8″ screws.
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Bayou Jumper revB Assembly Manual
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A new addition to the revB kit is a red/green LED pilot light and Tx/Rx
indicator feature. This bi-color LED indicator can be treated as an option.
If, after reading through these instructions, you are uncomfortable with this
“Pittsburg style” of assembly, you can simply omit these steps. There will be
no effect on the performance of the transceiver.
Mount the two resistors:
R19 (1 K, BRN BLK RED) and R20 (2.2 K RED RED RED) on the underside of the
front panel. These are installed “Pittsburg style” as shown in the photos.
Bend the leads to form them as in the lower image at right, then trim them as
in the upper.
Solder both resistors to their pads as shown at right.
Note that two leads of the bi-color LED (D4) will be soldered onto the same
pads as the right-hand ends of the resistors.
Install the bi-color LED (D4), also on the
underside of the front panel, again Pittsburg style.
GREEN GND
RED
The LED has three leads.
The longest lead is the common cathode
(negative). The next longest is the RED anode (positive), and the shortest is the GREEN
RED
anode.
GND
GREEN
Be sure to carefully observe the polarity of the
LED leads as shown in the photo, and gently
bend the leads away from the body, as shown.
Then bend the leads up parallel to the body, and trim the leads so that the LED can be positioned perpendicular to the PC board, with its tip touching the board, so that it will shine through the open center of the arrow-shaped tuning index marker.
revised 13 March 2021
Bayou Jumper revB Assembly Manual
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The RED anode lead should be soldered to the pad marked RED, which already has
one lead of R19 attached. The GREEN anode lead should be soldered to the pad
marked GREEN, which holds a lead of R20. The cathode lead should be soldered
to the GND pad.
Locate the 12″ jumper wire supplied in the
kit the one with a header socket at each end. Cut the wire in half, then
strip about 1/8″ of insulation from each cut end, and tin the exposed wires
with solder.
Solder one wire to the RxVcc pad on the underside of the front panel, and the other to the J7-7 pad. It would be a good idea to use a bit of tape, or perhaps hot glue, to provide some strain relief for these wires.
When the front panel is mated to the main PC board the socket ends of these
wires will be plugged into header pins on the main board:
the wire from pad J7-7 will plug into the J7-7 pin. the wire from pad RxVcc
will plug into the J7-9 pin (NOT the RxVcc pin)
The sockets on the ends of the two connecting wires are just a bit too tall to
fit between the front panel and the main board when they are plugged into the
header pins.
To make room, remove the little plastic spacer on each of the pins J7-7 and
J7-9. Just grasp the plastic spacer with your long nose pliers and pull
straight up. The
plastic part will slide off. The photos show how.
Here’s how the bi-color LED indicator works:
When the transceiver is in Tx mode, 12 V is supplied to pin J7-7 through SW1a.
J7-7 is connected through R19 to the RED anode of LED D4. Diode D1 serves to
isolate pin J7-9 from the 12 V supply. Therefore the RED portion of D4 will be
illuminated in Tx mode.
When the transceiver is in Rx mode, 12V is supplied to pin J7-9 directly
through SW1a, and is also connected to J7-7 through diode D1. Now 12 V is
being supplied through R20 to the GREEN anode of D4. So during Rx mode the
GREEN portion of D4 will be illuminated, in addition to the RED.
The GREEN portion of D4 is more efficient than the RED, and the human eye is
more sensitive to the green portion of the visible spectrum, so the green
light overpowers the red, and the indicator appears green.
If R20 were to be increased to about 24K to reduce the intensity of the green,
the green light would roughly balance the red and the colors would mix to
appear yellow/amber.
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Bayou Jumper revB Assembly Manual
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Mating the front panel with the main PC board
Place the front panel onto the standoffs. Secure it temporarily with two or
three screws and check the motion of the pots. If they do not turn freely, re-
heat the mounting lug(s), and adjust the angle(s) slightly as needed.
Remove the front panel temporarily. Then insert the power jack, key jack,
and headphone jack into the front panel, and tighten their nuts. Insert the
wires from the headphone connector and the key jack though the appropriate
holes in the board as you bring the boards together. Insert the red wire from
the power jack into the square +12 V ‘ pad on the PC board, and the black wire into the round
— ‘ pad on the PC board. Also plug in the two wires from
the LED. Plug them into the header pins marked J7-7 and J7-9.
Finish attaching the front panel using the rest of the six 6-32 x 3/8″ screws.
Gently pull the bus wires from the headphone and key jacks snug, and solder
them into place on the circuit board. Solder the two wires from the power jack
as well. Inspect the power jack lugs and wire leads to be sure there are no
accidental short circuits.
If the crystal pins are not centered under the front panel holes, re-heat the
solder and reposition them. Push two plastic insulating sleeves into the
crystal socket holes in the front panel, pressing them down over the crystal
socket pins.
Install the five knobs. Be sure the round knobs are positioned so that the set
screws bear upon the flatted portions of the shafts. The knob indicators
should line up with the markings on the panel. The rotary switch has no flat.
Adjust its knob so that it lines up with the three positions marked on the
panel. See Appendix C for some additional comments about the main tuning knob.
Install the ½” male-female threaded
standoff on the top of the front panel near the BNC jack. The standoff
replaces the supplied 3/8″ 6-32 screw that is normally inserted there. Use the
3/16″ 6-32 screw on top of the standoff so that the phillips screw head
provides a “landing pad” for the crystal pin.
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Bayou Jumper revB Assembly Manual
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Should you need to separate the main board from the front panel for
adjustments or troubleshooting, remove the nuts from the key, headphone, and
power jacks, and remove the knobs. The crystal socket pins will slide out of
the nylon insulators with some gentle pulling.
Crystal Adapters
The Bayou Jumper has a front panel crystal socket to fit FT-243 or FT-241A
crystals, the old style Novice crystals that can still be found at hamfests.
The kit includes two HC-49 packaged crystals, for 7.030 and 7.122 MHz. These
are the two QRP watering hole frequencies where much of the QRP activity takes
place. Also included are two adapter boards that you can use to build your own
FT-243-compatible crystals. If your adapters look different from the ones in
the photo below, see Appendix H for additional information.
Assembly of the crystal adapters is pretty straightforward. Trim the leads of
the HC-49 crystals and bend them so the body of the crystal sits flat on the
board. Solder them down to the two round pads. Cut two lengths of #10 bus wire
about 5/8″ long, and solder down to the two rectangular pads. Check the
spacing against the crystal socket on the PCB. Using a fine file or emery
board, taper the ends of the #10 wires so they insert into the sockets
smoothly.
As an alternative to the #10 solid wire, you can obtain 3/32″ brass tubing or
rod at Hobby Lobby or other hobby or hardware stores.
If the builder has any of the old style FT-243 or FT-241A crystal holders, the
miniature HC-49 size crystals can be mounted inside the cases for a truly
vintage appearance!
To mount the “tall” HC-49U crystals in an FT-243 case may require some
hollowing out to create enough space. They will fit very nicely in an FT-241A
case, needing nothing more than perhaps filing down the contact posts
slightly. HC-49S crystals, the “low profile” ones, will fit either case with
no modification.
Crystal adapter
FT-241A
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Bayou Jumper revB Assembly Manual
FT-243
page 20 of 47
Receiver Tuning Setup
With all board-mount components installed, the next step is to set up the
receiver for the desired tuning range, and the regeneration control for the
proper range. A calibrated CW receiver or a calibrated 40 m signal source is
needed, or use the Bayou Jumper’s spotting function to calibrate the receiver.
Connect the 12 V power plug cable to a regulated 12 V supply or battery.
A fused or current limited supply is recommended, at least for initial
testing. Insert the plug into the 12 V power jack. With the radio OFF it will
draw a few µA from the supply through the ESD protection circuit, when ON and
in RECEIVE it will draw around 20 to 25 mA.
Appendix M lists some expected values of supply current and RF output.
Be sure to read Appendix L before connecting anything other than a standard
set of stereo headphones or an unpowered speaker to the PHONES jack. The audio
output amplifier IC chip will be damaged by improper connections.
Plug headphones or unpowered computer speakers into the PHONES jack
of the Bayou Jumper. The isolated stereo jack is wired to place the left and
right earpieces in series.
Turn the Bayou Jumper power switch to the RECEIVE position. Turn the
ATTEN, and REGEN controls to their fully clockwise positions, the VOLUME to
about mid-scale, and the TUNE control to the lowest frequency position (fully
counter-clockwise). You should hear a hiss in the headphones, indicating that
the receiver audio is operating.
If you have a frequency counter or oscilloscope with a high-impedance
probe, you may sample the oscillator frequency at the test point labeled TP1
on the back side of the board.
Otherwise, if you have a calibrated CW or shortwave receiver, turn it on, and
make sure it is in the CW mode. Place the Bayou Jumper next to it. Sweep the
receiver tuning from roughly 6.0 MHz to 8.0 MHz. Somewhere within that range
you should hear the oscillations of the regenerative detector, which should
fall near 7 MHz.
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Bayou Jumper revB Assembly Manual
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Alternately, if a calibrated receiver is not accessible, a separate
transmitter may be used to generate a calibration signal. Connect the
transmitter into a dummy load, and connect a short length of wire to the BNC
connector of the Bayou Jumper. Tune the transmitter to 7.050 MHz, and key it.
Rotate the tuning control of the Bayou Jumper until you hear the transmitted
signal, which should fall at approximately halfway through the tuning range.
If it is not heard, readjust the transmitter to 7.000MHz or 7.100 MHz to see
if the signal can be heard.
Finally, if neither of these options is available, the transmitter spotting
feature allows you to use the transmitter master oscillator as a reference
signal. Insert the 7.030 MHz crystal into the crystal socket, place the Bayou
Jumper power switch in the RECEIVE position, and turn the ATTEN control fully
counter clockwise. Turn the VOLUME control knob to the 10 o’clock position,
and the REGEN control fully clockwise. Depress the key knob, and rotate the
TUNING knob through its range. You should hear two heterodynes, and the
receiver will be tuned to 7.030 at the midpoint between the two. This point
should occur at approximately the `3’ position on the tuning knob.
If no signals are heard, the regenerative detector may not be oscillating.
Jump ahead to the Regeneration Setup section to adjust the regeneration range.
If the frequency of the Bayou Jumper regenerative oscillator is more than
approximately 10 kHz off, you may use the trimmer capacitor C30 to adjust the
frequency of the oscillation. Using a fine jeweler’s screwdriver, rotate the
trimmer capacitor setting approximately 1/8 of a turn until the desired
frequency is set.
If the trimmer capacitor C30 has insufficient range, you may squeeze together
the turns of the toroid transformer L1 to lower the oscillation frequency, or
spread them further apart to increase the frequency, then fine-tune using C30.
If the tuning range is still not satisfactory using both C30 and by adjusting
the turns spacing of L1, your course of action will depend on whether the
frequency range is too low or too high.
Should you need to separate the front panel from the main circuit board,
remove the mounting nuts from the POWER, PHONE and KEY jacks. The front panel
can be removed without having to de-solder anything.
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Bayou Jumper revB Assembly Manual
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If the tuning range is too low below the 7000-7150 kHz range and you have
spread out the turns of the 19 turn winding as far as possible, you will need
to remove a turn from that winding. Just cut the wire where it emerges from
the PCB on the outside of the core and pull the wire out from under the core
to remove one turn. Use a solder sucker or solder wick to clean out the hole,
and feed the wire back through to gauge its new length. Pull it back out to
strip and tin the end then re-insert, snug it up, and solder in place.
If the tuning range is too high and you have squeezed the 19 turn winding as
tightly as possible there are two possible actions, to be taken only after you
have verified that C4 and C20 have not been accidentally swapped. C20 should
be 120 pF (marked “121”)
- Add some additional capacitance to the tank circuit by installing the capacitor C20a. A 10 pF capacitor is supplied with the kit in case it is needed.
- Or, you may add a turn to the main winding of L1. This probably requires
completely removing the toroid though, with care, you could re-wind 20 turns
while the core is still attached by the other two windings.
Adding more capacitance will have the additional effect of slightly reducing the width of the tuning range, while adding inductance (extra turn) has the opposite effect. The tuning range in either case should still be more than adequate to cover the portions of the band needed.
Once one of these processes has been done, repeat the calibration steps to set the range of the tuning control.
Regeneration Setup
The next step in receiver setup is to adjust the regeneration control range.
Check out the MP3 audio clips posted in the Files area of the Bayou Jumper Yahoo Group if you are unfamiliar with how a regen receiver should sound.
Set the TUNING control to the middle of its range, the VOLUME control to midrange, and listen to the headphone audio. It may help if an antenna is connected to the Bayou Jumper. Rotate the REGEN control knob from maximum to minimum, and back. You should notice a marked change in the audio hiss in the headphones at some point along the knob travel, as the detector JFET Q2 enters and exits oscillation. This should occur near the midpoint of its travel. If this is not the case there are two likely scenarios:
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Bayou Jumper revB Assembly Manual
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(1) If there is no change to the hiss while adjusting the REGEN control, it
means that the regeneration must be adjusted to either increase or decrease
the amount of RF feedback in this circuit. If, for any setting of the REGEN
control, you can hear the heterodyne of the Bayou Jumper’s regenerative
oscillator in your separate calibrated receiver, or, hear the signal of a
nearby CW transmitter or the spot frequency when keying, then you have too
much regenerative feedback.
(2) If no signals are heard, or the detector oscillations cannot be found in
the test receiver, then the detector may not be oscillating because there is
too little feedback through the tickler winding.
In either case (1) or (2) above, the first step is to adjust trimmer capacitor
C21, next is to squeeze or spread the 4 turns of the tickler winding, and as a
last resort, adding or removing a turn from the tickler winding. It is very
unlikely that the tickler should have to be re-wound.
Adjusting the tickler winding and trimmer capacitor C21
Set the regeneration control, R10, about 30% of its clockwise travel. Set the main tuning to the low frequency end of the tuning range. Try to adjust C21 so that oscillation just begins (as evidenced by an increase in hiss in the audio) then back off C21 until the detector just barely drops out of oscillation. At this point the regeneration control, R10, should be able to being the detector smoothly into and out of oscillation somewhere around the 30% – 50% point of its travel.
If it does not appear that the detector oscillates for any setting of C21, try squeezing the 4 turns of the tickler winding more tightly together. If still no oscillations, or oscillation only starts near the extreme CW rotation of the control, install the optional ceramic capacitor C31 (22 pF) and repeat the above procedure.
Conversely, if the detector always oscillates, no matter the setting of C21 or R10, be sure that C31 is NOT installed, and spread out the turns of the tickler winding. If that does not allow the detector to cease oscillating, decrease the value of C26. A good first try would be 82 pF followed by 75 pF.
If, on the other hand, you are not hearing any oscillations in your separate CW
receiver, or hearing any CW notes in your Bayou Jumper Receiver when
connected to an antenna, then you have insufficient regenerative feedback. In
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Bayou Jumper revB Assembly Manual
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this case, install C31, the 22p capacitor, and re-test. Re-check the receiver
calibration. It’s a good idea to do a final check with the radio installed
into its box, but before screwing down the panel.
When the receiver calibration is satisfactory, to fix the turns in place,
paint the toroid with a light coating of clear fingernail polish.
Finally, secure the panel to the box’s wood posts with the four #6 sheet metal
screws. Be careful not to overtighten them, which could strip the threads
you’re cutting into the pre-drilled wood posts.
Troubleshooting
If your Bayou Jumper does not operate after assembly, repeat the visual
inspection of solder joints. Especially inspect the leads of L1 for good
solder connections. Compare the component placement diagram with the
instructions to be certain that all components were installed in their correct
locations. In particular, be sure that C20 and C4 have not been interchanged,
which would make to tuning range too high in the band. C20 should be 120 pF
and C4 should be 100 pF.
A check of voltages at strategic locations on the board while under power can
serve to isolate problems to a particular circuit. The table on the next page
lists nominal voltages for the unit in receive and with the regeneration
control fully counterclockwise. If an entry is marked ‘XXX’ do not attempt to
measure it.
The XXX voltages are high impedance RF points where a DC reading will possibly
be erroneous due to the high RF voltage present, or the stray capacitance of
the voltmeter probe could cause the circuit to misbehave.
For those who may be experiencing the charm of a regenerative receiver for the first time, there are a series of MP3 audio files posted on the Bayou Jumper Yahoo Group, in the Files area. These give examples of what the receiver should sound like under various tuning conditions. The file names explain to what you are listening.
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Bayou Jumper revB Assembly Manual
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MPF102
2N3904
2N7000
G D S
78L06
C
E B
IRF510
OUT
IN GND
D S G
Voltage Chart — values are approximate, based on a 12.0 V power supply
Component ID Q1 Q2 Q3 Q4 Q5 Q6
revised 13 March 2021
Pin
Expected V
Measured V
E
5.4
B
6
C
6
G
0
1.5 to 3.5 V for revA and earlier
D
between 0.5 and 0.6 V for revB
S
6
E
0
B
0.65
C
between 2 & 4
G
xxx
D
12
S
xxx
G
3
D
12
S
xxx
G
12
D
0
S
0
Bayou Jumper revB Assembly Manual
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U1
1 (square pad)
0
2
5.7
3
5.7
4
5.7
5
5.7
6
12
7
0
8
5.7
U2
1 (OUT) nearest
6
2 (GND) middle
0
3 (IN) nearest C25
12
R8
WIPER PIN
2 to 6 as R8 is varied
R10
WIPER PIN
0 to 6 as R10 is varied
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Bayou Jumper revB Assembly Manual
page 27 of 47
Operating the Radio
Operation of the Bayou Jumper is fairly straightforward. Make sure you are
operating into an antenna with good VSWR 1.5:1 or better. The transmitter in
the Bayou Jumper is not overly sensitive to VSWR, but it has no built-in
protection against very mismatched loads that could cause damage. It is best
to use a tuner with a resistive-bridge type VSWR sensor, such as the 4SQRP 4S-
Tuner.
Make sure there is a crystal inserted into the socket before transmission.
Turn on the receiver and verify that you hear signals.
To spot the transmitter crystal frequency, first turn the ATTEN control fully
counter-clockwise (minimum signal). Turn the REGEN control fully clockwise.
Turn the VOLUME control to the 10 o’clock position. Press the key in the
RECEIVE setting, only the Master Oscillator is activated, and no signal is
transmitted. Rotate the tuning control. As you rotate the control, you will
hear two loud regions of heterodyne whistle noise, with a dead zone in the
middle, caused by the oscillator RF overloading the regenerative detector. You
won’t be able to zero-beat exactly, but you can come close knowing the
transmitter frequency is in the middle of the two noise regions.
See Appendix G for an alternate method of spotting the crystal.
Returning the REGEN, ATTEN, and VOLUME controls to their normal positions, you
will likely hear signals. You can either call CQ or reply to a call as you
would with any other rig just be aware that you cannot change the transmit
frequency without changing crystals! If you plan to work other Bayou Jumpers,
be sure to tune around a bit after calling CQ just like back in pioneer
times!
There is an on-line Group devoted to the Bayou Jumper at
https://4sqrp.groups.io/g/BayouJumperKit
There is large and active community of builders who can help each other with
issues that may arise, so new builders are encouraged to join up!
Once you have your Bayou Jumper built and working, apply for a Secret Agent
Number and get a matching serial number decal for your radio. See the Bayou
Jumper web page, in the documentation area, for details
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Bayou Jumper revB Assembly Manual
page 28 of 47
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Bayou Jumper revB Assembly Manual
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Bayou Jumper revB Assembly Manual
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Bayou Jumper revB Assembly Manual
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Top copper pattern and silkscreen, viewed from top side
Bottom copper pattern and silkscreen, viewed from bottom side
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Bayou Jumper revB Assembly Manual
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Front panel, top and bottom views
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Bayou Jumper revB Assembly Manual
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Photos by WØEB.
Top:
Populated PCB, before toroid installation note builder-supplied socket for U1
Bottom: Populated PCB, bottom view, with toroid mounted on bottom
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Bayou Jumper revB Assembly Manual
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Design Notes
Tuning range approximately 140 to 160 kHz enough to cover the Extra Class CW
band through the old “Novice Band.”
One knob tuning no bandset/bandspread needed.
Only one toroid to wind in the receiver section. Etched PCB inductors used in
the transmitter section.
Varactor tuning employing readily available Schottky diodes as varactor
diodes. Regeneration control also employs a “Schottky varactor” as the
throttle capacitor.
Use of potentiometers controlling only the DC bias on the varactors for tuning
and regeneration means the controls are not “hot” with RF, so “hand effect”
detuning is minimized.
RF attenuator control, which is useful when employed with full-scale antennas.
Robust headphone audio, and will drive a small speaker with modest volume.
Current drain on receive about 20 to 25 mA, less than 600 mA on transmit at 5
W
Harmonics and spurious down about 50 dB with respect to the fundamental,
exceeding the FCC 43 dBc requirement.
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Bayou Jumper revB Assembly Manual
page 35 of 47
Bayou Jumper rev B Bill of Materials (31 December 2020)
Inv Quant Part ID(s)
1
C31
Description CAPACITORS 22 pF NP0 ceramic, 0.1″ LS
2
C21,C30
4-20 pF trimmer capacitor
3
C4, C18,C26
100 pf NP0 ceramic, 0.1″ LS
1
C20
120 pF NP0 ceramic, 0.2″ LS
1
C16
220 pF NP0 ceramic, 0.2″ LS
1
C23
390 pF NP0 ceramic, 0.2″ LS
1
C22
470 pF NP0 ceramic, 0.2″ LS
3
C8,C14,C15
0.001 µF 200V NP0 ceramic, 0.2″ LS
1
C28
0.0033 µF NP0 ceramic, 0.1″ LS
4
C1,C2,C11,C17 0.01 µF ceramic, 0.1″ LS
1
C24
0.033 µF ceramic, 0.2″ LS
7
C5,C7,C19,C25, 0.1 µF ceramic, 0.1″ LS
C27,C29,C32
1
C10
1 µF electrolytic, 0.1″ LS
4
C3,C6,C9,C13, 4.7 µF electrolytic, 0.1″ LS
1
C12
47 µF electrolytic, 0.1″ LS
DIODES
3
D1,D2,D3
1N5819 Schottky diode
1
D4
Red/Green bi-color LED, 5 mm,
common cathode, water clear lens
1
J1
1
J2
2
J3,J4
2
J5,J6
1
L1
1
L2
CONNECTORS BNC jack – antenna 2.1×5.5 mm coaxial power jack 1/8″ stereo phone jack Molex® pins crystal socket INDUCTORS T68-2 iron powder toroid core 1.0 µH molded choke
1
L4
470 µH molded choke
2
Q1,Q3
1
Q2
2
Q4,Q6
1
Q5
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TRANSISTORS 2N3904 BJT transistor, TO-92 MPF-102 JFET transistor, TO-92
IRF-510 MOSFET, TO-220 2N7000 MOSFET, TO-92
Bayou Jumper revB Assembly Manual
Marking
Notes
22J , 22, or 220
pink body
101 121 221 391 471 102 332 103 333 104
Optional – do not install yet Note orientation of flat side
1 µF 4.7 µF 47 µF
Note polarity Note polarity Note polarity
1N5819
Note polarity Note polarity, installed under front panel
Yellow body
Wide SilverBrown-GoldBlack-Silver Wide SilverYellow-VioletBrown-Silver
L2 is the physically larger choke
L4 is the physically smaller choke
2N3904 MPF-102 IRF-510 2N7000
Static sensitive Static sensitive
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1
R16
2
R17, R19
RESISTORS 100 1/4W 5% resistor 1.0 K 1/4W 5% resistor
1
R20
2.2 K 1/4W 5% resistor
1
R3
2.7 K 1/4W 5% resistor
2
R7,R12
3.3 K 1/4W 5% resistor
1
R5
33 K 1/4W 5% resistor
1
R15
100 K 1/4W 5% resistor
1
R13
330 K 1/4W 5% resistor
4
R9,R11,R14,R18 470 K 1/4W 5% resistor
2
R2,R4,
1.0 M 1/4W 5% resistor
BRN-BLK-BRN BRN-BLK-RED
RED-RED-RED
RED-VIO-RED ORG-ORG-RED ORG-ORG-ORG BRN-BLK-YEL ORG-ORG-YEL YEL-VIO-YEL BRN-
BLK-GRN
R19 is installed under the front panel installed under the front panel
1
R1
3
R6,R8,R10
1
SW1
1
U1
1
U2
1
X1
1
X2
2
1 1 2 1 1
3 1 4 15 6 1 1 1 1 4 1 4 1 4 6 ft
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POTENTIOMETERS 5.0 K potentiometer 50 K potentiometer SWITCH 4-pole 3-position rotary switch INTEGRATED CIRCUITS NJM2113 audio amp DIP-8 78L06 voltage regulator TO-92 CRYSTALS 7030 kHz quartz crystal HC-49 7122 kHz quartz crystal HC-49 Crystal Adapter PC board OTHER HARDWARE Front panel PC board Main PC board Nylon screw insulator/bushing 2.1×5.5mm coaxial power plug “chicken head” pointer knob, will require an Allen wrench, 1.5 mm Small control knob Large dial knob 2″ long x 3/8″ square wood post 3/8″ #6-32 machine screw 5/8″
6-32 F-F hex standoff ½” #6-32 M-F hex standoff 3/16″ #6-32 machine screw
3/8″ #6-32 F-F hex standoff Key knob #6-32 hex nuts PCB “leaf spring” lever #6
flat washers 3/8″ #8-32 BRASS screw #6-32 sheet metal screws AWG #24 enameled
magnet wire
Bayou Jumper revB Assembly Manual
B5 02 B5 03
NJM2113 78L06
Use supplied socket
7030 7122 Cajun Crystals
Rev B Rev B
blue solder mask green solder mask Use with J5 & J6 Mates with J2 OFF-Rx-Tx switch
Main tuning
For xtal test post For xtal test post For CW key For CW key For CW key For CW
key For CW key For CW key joins panel to box For toroid L1
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6 in 6 in 3 in 12 in 5
1
TP1, V-reg, Rx-Vcc, J7-7, J7-9
R5a C33 Filter switch
AWG #22 tinned bus wire AWG #10 bare copper wire RED/BLACK insulated wire
“Dupont” female-female jumper wire Header pins, 1 conductor
DIP socket 8 pin Optional parts (Not supplied with kit) for modifications TBD,
could be potentiometer TBD, approx. 560 pF SPST miniature toggle
Fine Tuning
1K potentiometer Bourns series PV09, 25 mm shaft, center detent Bourns PTV09A- 4225F-B102
C20a
10 pF NP0 ceramic, 0.2″ LS
10
For crystal pins
LED connections
Socket for U1 See manual appendices
For Soup’er Up’er For Soup’er Up’er Same physical size & type as R1 In case
needed to move tuning range lower
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Bayou Jumper revB Assembly Manual
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APPENDICES
A. Rotary Switch Options
In case the indexing key washer should slip out of place while working with the switch, the photo at right shows the correct position of the washer relative to the index post on the body of the switch.
INDEX POST
The shaft of the stock switch is a little too long to allow the selector knob to sit down close to the panel. It will not interfere with closing the lid of the recommended box, but if the appearance is not to your liking you can shorten the shaft. Be sure to leave at least 1/4″ of shaft remaining. The best procedure is to hold or clamp the end of the shaft (so as to not apply stress to the switch body, and use a jeweler’s saw, fine hacksaw, coping saw, or a band or scroll saw. Alternatively a cutoff disk in a Dremel tool could be used. It is even possible to use diagonal cutters, but don’t try to make one clean cut through the shaft, best to nibble away until the desired length is attained. NA1MH’s photo at right shows such a shortened shaft.
8 O-Ring
B. Key Stiffness
The spring lever of the built-in key is made of thin double-sided PCB stock. If the touch feels too light, a replacement lever can be fashioned from thicker (1/16″) stock.
Alternatively, the stock lever can be
retained, but a “helper spring” made from 1/16″ PCB stock can be installed as
shown in the photo. The length of the
helper plate will determine how much
stiffness is added.
C. Main Tuning Knob
The metal skirt around the base of the tuning knob may have some rough edges
that could scratch the finish of the panel. Use a piece of emery paper on a
flat hard surface to sand the edge until it is flush with the plastic
undersurface of the knob. A washer made of felt might be fashioned to slip
between the knob and the panel, to prevent scratching and to provide some
extra friction for the dial action.
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Bayou Jumper revB Assembly Manual
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D. Routing wires to the main PCB for installations of mods or accessories.
Since there is room under the main PCB as installed in the recommended box,
the possibility of adding accessories such as an audio filter, sidetone
oscillator, keyer, etc, are certainly attractive. Several “wireways” pre-
drilled ¼” holes in the circuit board have been provided to allow for
passing wires from above and below the main board. The holes are isolated from
the top and bottom ground planes.
E. Tuning Range
An easy way to change the tuning range is to change the value of R5. Smaller resistance will increase the range, while larger resistance will decrease it. The downside of increasing the range is that the tuning will become more non- linear tuning faster at the lower end of the band. R5 should not be decreased below about 5 to 10 k or so.
A pair of pads, designated R5a, have been provided. They are shorted
CUT HERE
across with a thin trace on the bottom of the PCB that must be cut if
R5a is to be used. Inserting extra resistance, or better still, a
potentiometer, at R5a will move the bottom of the tuning range up in
frequency, while leaving the upper end virtually unchanged. So if most
of the use of the radio were going to be in the 7100 to 7125 kHz
region, it could be spread out over nearly the full travel of the main
tuning control. But the range could be easily restored to cover the lower part of the band.
A potentiometer at R5a does act rather like a fine tuning control, but its effect is greatest at the low end of the range, diminishing to no effect at all at the top end.
F. PCB footprints for optional additional components (not supplied in the kit)
Mounting pads and connection points have been provided for an additional potentiometer (of the same physical type as the others in the kit) and a miniature SPDT toggle switch. Adjacent to each are a set of pads that can be used to make wire connection to the parts.
Possible uses for the potentiometer could be a fine tuning control, a keyer speed control, a sidetone pitch or level control. Bourns 9 mm pots, series PTV09A, 25 mm shafts, will fit the footprint.
The SPDT switch could switch an audio filter in or out, or select resistors at R5a to change the tuning range. Marlin P Jones # 25010SW (ON-OFF-ON), or similar, fits the footprint.
On the underside of the front panel are centering marks to allow drilling a hole properly positioned for these optional parts.
A pair of pads are provided for an optional capacitor, C33, to be installed
across the feedback
resistor of the audio amplifier IC. A few hundred pF has been found to
“mellow’ the audio sound of the receiver. The larger the capacitance the more
the highs are suppressed.
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Bayou Jumper revB Assembly Manual
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G. Crystal Spotting
Some builders may discover that the spotting feature does not suit their
needs. The strong RF signal from the crystal oscillator, even when the final
amplified stage is not in use, overloads the regenerative detector and pulls
the detector to oscillate a frequency some kHz removed from the actual receive
frequency as shown on the dial.
An outboard crystal spotting oscillator could be constructed. There is a
description on the Bayou Jumper Yahoo Group of an example circuit.
Another method is to disconnect the antenna and connect the crystal across the
antenna terminals. When the receiver is tuned across the crystal resonant
frequency a “pop” or “thump” is heard in the receiver. The method is quite
precise and allows setting the receiver within a few hundred Hz of the true
crystal frequency.
To simplify this process the BNC antenna connector has been relocated close to
one of the PC board mounting standoffs. Installing the ½” standoff (topped
with with a 3/16″ 6-32 screw) on top of the front panel, replacing one of the
3/8″ 6-32 screws, allows an FT-243 sized crystal to be easily connected
momentarily between the center pin of the BNC jack and the grounded standoff.
There is an MP3 recording posted on the BayouJumper Yahoo group site that
demonstrates the sound of the receiver tuning past the crystal frequency.
H. Alternate Style Crystal Adapters
CUT THIS TRACE IF L IS ADDED
These adapters allow for a series trimmer capacitor and/or a series inductor to be added. The crystal is installed in the same manner as the originals but, if either the capacitor or inductor were to be added, cut the associated trace(s). The solder mask has been removed above those traces for better visibility.
N2HTT photo
CUT THIS TRACE IF C IS ADDED
The series capacitor will raise the frequency, while the series inductor will lower it. If both are used a somewhat wider range of adjustment may be attained.
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Bayou Jumper revB Assembly Manual
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I. Connection points for potential modification or additions
There are nineteen extra pads on the PC board that connect to strategic points
in the circuit. These points have been selected because they may be useful for
modifications or additions such as sidetone, audio filter, keyer, fine tuning,
digital dial, etc.
Each point is identified on both the top and bottom silkscreens with a circle
and an alphanumeric designator, as listed below. They are also identified on
the schematics with the
same designations.
A
connects to the wiper of the main tuning potentiometer, R8
B
connects to the cathode of the main tuning varactor diode, D3
TP1 connects to the Q2 end of the tickler winding for scope or counter
J7-1
)
J7-3
) these pads connect to the terminals of the optional potentiometer
J7-5
)
J7-7 J7-9 J7-11 J7-13 J7-15 J7-17
connects to the +12 V supply during both Tx and Rx operation connects to the +12 V supply during Rx operation only connects to the input resistor of the audio amplifier IC, U1 connects to the internal key line connects to GND during Rx, is floating during Tx connects to the collector of the audio pre- amp transistor, Q3
J7-19 J7-21 J7-23
) ) these pads connect to the terminals of the optional SPDT switch )
J7-25 connects to the wiper of the volume control potentiometer, R6
KEYER-TIP KEYER-RING KEYER-GND
) These pairs of pads can be used to connect the stereo key jack to a ) keyer. Connect tip, ring, and sleeve from the jack to one pad of each ) pair, then use wire leads from the other pads to the keyer circuit
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Bayou Jumper revB Assembly Manual
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J. The NA1MH Soup’er Up’er Accessory
David Martin, NA1MH, designed an add-on for the Bayou Jumper that provides a
sidetone, a fine tuning control, and the NMØS HI-PER-MITE audio filter.
This accessory is not currently being kitted and supplied by Four State QRP
Group, but “previously owned” units are occasionally offered on various QRP
forums, and documentation is available for download.
A small PC board is attached to standoffs under one corner of the main board
and is connected to the main board using the connection points described in
Appendix I, above. No trace cutting is required. Provisions for mounting a
fine tuning potentiometer and filter IN/OUT switch have already been made on
the revA circuit board (see Appendix F) and the underside of the front panel
is marked to locate the holes to be drilled to accommodate the extra controls.
NA1MH photo of beta version WØEB photo
K. Using a keyer
During transmit key-down intervals the keying current of the Bayou Jumper is about 750 mA, which will exceed the capability of many keyer output circuits. A robust PNP power transistor, a MOSFET power switch, or a relay, are called for.
In the special case of the Four State QRP Group’s EZ-Keyer, the supplied BS170 output transistor could be replaced with a heftier MOSFET such as the IRF510.
Any one of the circuits at right, suggested by NMØS, could be used to interface between a conventional keyer and the Bayou Jumper.
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Bayou Jumper revB Assembly Manual
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L. Connecting external audio devices (amplifier, filter, etc)
The Bayou Jumper’s audio amplifier device (NJM2113) employs a differential
output stage which is not referenced to the circuit ground. That is why only
the tip and ring contacts of the stereo jack are connected, and the sleeve is
left floating. This type circuit does not require the large series capacitor
such as used with LM386 amplifiers, and as a result, the low frequency
response of the audio stage is improved.
But since both outputs of the IC are internally biased at approximately half
the supply voltage, connecting either output pin to circuit ground will
produce a short circuit which will irretrievably damage the chip.
If you want to use an external amplifier, or external narrow band audio filter
(such as a NEscaf or HI-PER-MITE) you must use a DC blocking capacitor in
series with both the tip and ring connections. Check the schematic of your
external device. A blocking capacitor may already be in place in the signal
lead, so you would only need to add one in the common lead.
Since most of these devices have a relatively high input impedance, the
capacitance does not need to be very large you may be able to use a common
0.1 µF capacitor. If an electrolytic capacitor is used, the positive side
should be connected to the tip and/or ring of the headphone jack.
The diagram below illustrates a proper connection to a HI-PER-MITE audio
filter (top) or other generic active audio device (bottom).
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Bayou Jumper revB Assembly Manual
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M. Measured values from a rev B, beta build Bayou Jumper
Tuning range:
Very tight 19 turn main winding
With C30 at maximum capacitance, initial range was 6813 6959 kHz Adjusting
C30, only, yielded the result below
Dial setting 0 1 2 3 4 5 6 7 8 9
Rx zero beat frequency, kHz 7002.0 7004.3 7030.1 7063.3 7087.7 7107.8 7125.6 7142.6 7159.3 7162.0
Receive mode current draw (12.4 volt supply): Key up, normal headphone volume: 24 mA Key down (spotting mode): 71 mA
Transmit mode, idling current (12.4 V supply): Key up: 17 mA
Transmit power measurements: All voltages measured at the power jack, key down, 7120.1 kHz (7122 crystal)
Vsupply
at power jack
11.0 12.0
13.0 14.0
Fully charged 12 V, 7 A-hr AGM battery 3 x 18650 lithium-ion cells, fully
charged
RF output
Peak-peak volts
35.2 38.4 41.6 44.0 40.8
38.4
RF output
watts
3.1 3.7 4.3 4.8 4.2
3.7
Supply current
mA
360 395 425 455
PA efficiency
78% 78% 78% 81%
Harmonic suppression measured with a Rigol spectrum analyzer: All harmonics at least 50 dB below the fundamental
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Bayou Jumper revB Assembly Manual
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N. Critical Dimensions of PC Board and Enclosure
With some folks having trouble laying hands on the recommended Hobby Lobby
box:
http://www.hobbylobby.com/Crafts-Hobbies/Wood-Crafting/Unfinished-Wood/Wood-
Rectangle-Box-Set-with-Silver-Handle/p/25426-GA0369
The on-line sale is for a set of three boxes, of which the smallest is used.
The boxes can be purchased individually in stores, SKU# 662536S.
here are some dimensions which might help in a roll-your-own.
First the PC Boards: They were designed on a decimal inches grid. The primary
dimensions in those units, as specified to the manufacturer was:
7.225″ long x 4.850″ wide (183.515 mm x 123.19 mm)
actual measurements here, on a sample of two, agree within ability to measure
(< 0.5 mm)
The front panel is a complete rectangle of those dimensions The main PCB has
0.425″ x 0.425″ (10.795 mm x 10.795 mm) cutouts at the four corners The PC
boards are 1.6mm (0.063″) thick
The four mounting holes at the corners of the front panel are 0.15″ (3.81 mm)
in diameter, and their centers lie on the vertices of a 6.925″ x 4.550″
(175.895 mm x 115.570 mm) rectangle
The Hobby Lobby “small box” dimensions, in mm: (inside dimensions) 183 mm side
to side, 123 mm front to back, and 52 mm deep. cover is the same length and
width, except the depth is 21 mm the thickness of the wood sides is about 8
mm, and the top and bottom are about 2 mm thick.
To fit the completed kit into a box there must be a clearance, measured from
the bottom surface of the front panel to the inside bottom of the box, of 28
mm (1.1″) , and 20 mm (0.8″) from the top surface of the front panel to the
inside surface of the top of the box.
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Builder’s Notes:
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Bayou Jumper revB Assembly Manual
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References
- 4SQRP.com
- Toroidophobia
- Wood Box With Handle Set | Hobby Lobby | 662536
- Paraset.nl
- BayouJumperKit@4SQRP.groups.io | Home
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