1X2 Amp Schematics - With Pictures

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parts list and build instructions
R1, R4, & R5 4.7Ω 2W Carbon Film Resistor 3 Yellow-Violet-Gold
R2, R8, & R9 100Ω 2W Carbon Film Resistor 3 Brown- Black- Brown
R3, R6, & R7 10Ω 1/2W Carbon Film Resistor 3 Brown-Black-Black
VR1 100Ω 2W Potentiometer 1 Labeled
C1 100~180 pf Silver Dipped Mica Capacitor 1 100~180 / 500V
C2, C3, C4, & C9 1000 pf Silver Dipped Mica Capacitor 4 1000 or 102 / 500V
C5, C6, C7, & C8 .1 uf Ceramic Disc Capacitor 4 104 or .1
C10, C15, & C16 120 pf Silver Dipped Mica Capacitor 3 120 or 121 / 500V
C11, & C12 .01 uf Ceramic Disc Capacitor 2 103 or .01
C13 330pf Silver Dipped Mica Capacitor 1 330 or 331 /500V
C14 820pf Silver Dipped Mica Capacitor 1 820 or 821 / 500V
C17 150 pf Silver Dipped Mica Capacitor 1 150 or 151 / 500V
C18 22 uf Electrolytic Capacitor 1 22 uf / 25V
C19 22 pf Ceramic Disc Capacitor 1 22
C20 .03 uf Silver Dipped Mica Capacitor 1 Large Cap. (Not Labeled)
VC1 Trim Capacitor 1 465
D1 3A / 1000V PIV Silicon Rectifier 1 1N5408
D2 1A / 1000V PIV Silicon Rectifier 1 1N4007
D3 Glass Signal Diode 1 1N4148
D4 LED Indicator assy. 1 Blue LED / Resistor Pkg.
TR1 Driver Section Power Transistor 1 SD1446 / 2SC2879 (See Note)
*Above transistor depends on which model is being constructed – SD1446=450V+ / 2SC2879=450V+ HDV
TR2, & TR3 250 Watt RF Power Transistor 2 2SC2879
TR4 Switching Transistor / TO-92 1 PN2222A
CHK1, 5, & 7 ½” x ½” Ferrite Core 3
CHK2, 3, 4, & 6 ¼” x ½” Ferrite Core 4
T1, T3 ½” x ½” Ferrite Transformer Core 2
T2 ½” x 1” Ferrite Transformer Core 1
T4 ½” x 1-1/4” Ferrite Transformer Core 1
SW1 SPST Switch 1
RLY1 DPDT Relay 1
FAN1 3-1/4” Fan Assy. 1
Page 1
Designator Description QTY Code Check
FG1 3-1/4” Fan Guard 1
Conn1, & Conn2 Panel Mount SO239 UHF Connector 2
Conn3 ¼” Stereo Phone Jack 1
Cabinet Aluminum Enclosure Assy. w/ Bracket 1
HS1 Aluminum Heat Sink 1
CB1 Pre-Drilled Copper Clad Circuit Board 1
CB2 Copper Clad Circuit Board 1” x 1” 1
PS1, 2, 3, & 4 Pre-Cut Transistor / Pill Strips 4
SCK1 LED Mounting Clip (Packaged w/ LED) 1
KB1 Control Knob 1
WIRE-1 9-1/2” Length of #14 Silver/Teflon Wire 1
WIRE-2 37” Length of #16 Silver/Teflon Wire 1
WIRE-3 23” Length of #20 Silver/Teflon Wire 1
WIRE-4 18” Length of #20 Hook-up Wire (Color 1) 1
WIRE-5 21” Length of #20 Hook-up Wire (Color 2) 1
WIRE-6 19” Length of #12 Power Cable 1
COAX 8-1/2” Length RG316 Coax 1
HDW1 Hardware Kit (See Below)
SHCS #4 40 x ¼” Socket screw 8
SHCS #6 32 x ¼” Socket screw 12
Pan Head Sheet Metal Screw 2
Pan Head Machine Screw #6 32 x ½” 4
#6 Lock Washer 2
#6 32 TPI Machine Nut 4
#6 Solder Lug 3
Pan Head Machine Screw #8 32 x ¾” 4
#8 Lock Washer 3
#8 32 TPI Machine Nut 4
Rubber Feet 4
Rubber Grommet 1
Scrap circuit board material 1
Heat sink lubricant 1
Label Sheet 1
Assembly Instructions
Step 1
Parts Needed: Heat Sink (HS1)
Circuit Board (CB1)
1ea. 200 Watt RF Power Transistors (TR2)
2ea. SHCS #4-40 Socket Machine Screw
Tools Needed: Ultra Fine Sharpie Marker
Power Drill (Battery powered is best)
1/8” drill bit
3/32” dill bit (#40 size works better)
Center Punch
4-40 Tap & Handle (Needed if 3/32” drill bit used)
Procedure:
1, Position circuit board on top of heat sink as shown in photo frame #1 with the front of the board flush with the front
of the heat sink. Slide board to the right until there is a 7/16” overlap of the board. Mark heat sink though the two
holes of board as indicated in the photo.
2, Remove board and enlarge the two holes used for marking the heat sink, and the two along the right side of the
board using the 1/8” drill bit as indicated in photo frame #1.
3, Use the center punch to mark drill points on heat sink. Bore the two drill points to a depth of about 3/8 of an inch
with the 3/32” / #40 drill bit. If a 3/32” drill bit is used, then the two holes should be threaded with the 4-40 tap. If a
#40 bit is used, the #4-40 x ¼” screws will self tap.
4, Return board to heat sink and mount with the two #4-40 socket machine screws. Carefully place the power
transistor in the front cutout and mark the heat sink at the two transistor mount drill points. Carefully remove
transistor and do the same with the two remaining cutouts. Return transistor to container. Remove circuit board from
heat sink and bore the six holes using the same techniques used in procedure 3 with one exception, after boring the six
holes, dress the surface of the heat sink so that the bored holes are clean and flush. It is of the utmost importance that
when the transistors are mounted, they make complete and full contact with the heat sink. A good counter sink bit
turned by hand can assist in this task. When finished, slide a straight edge across heat sink to check for
inconsistencies.
5, Remount circuit board on heat sink. At this point, the assembly should look as that in photo frame #2.
Page 3
Step 2
Parts Needed: Circuit board / heat sink assy.
2ea. Pan Head sheet metal screws
DPDT Relay (RLY1)
1” x 1” copper clad circuit board (CB2)
Pre-cut transistor / pill strips (PS1, 2, 3, & 4)
Bottom half of aluminum enclosure (Cabinet)
2ea. Panel mount SO239 UHF connector (Conn1 & Conn2)
4ea. Pan Head machine screw #6-32 x ½”
2ea. #6 lock washer
4ea. 32 TPI machine nut
2ea. #6 solder lug
Tools Needed: Ultra Fine Sharpie Marker
5 Minute Epoxy
#2 Phillips screw driver
Pliers or wrench for #6 machine nuts
Procedure:
1, Mount both SO239 UHF connectors from the inside of the enclosure making sure that the cut-out on the center
conductor of the connector is facing up. Use the lock washers on the upper mounting holes and the solder lugs on the
lower. Tip: Set the nuts on the lower screws so that one of the flats of the nut is facing down as to allow the bending
of the solder lug. This will provide clearance that may be needed later. See photo frame #3 for reference.
2, Bend solder lugs up as shown in photo frame #3. Lower circuit board / heat sink assy. into the enclosure and slide
under the two bent up solder lugs all the way back until it is against the back of the enclosure. At this point the two
mounting holes on the right side of the circuit board should line up with the two pre-drilled holes in the enclosure.
Mount the circuit board to enclosure using the two pan head sheet metal screws. See photo frame #4 for reference.
3, Position DPDT relay pins up in such a way that the two lone pins of the relay are to the rear of the enclosure and
the relay itself is centered between the two UHF connectors and against the rear panel of the enclosure. Mark the two
front corners of the relay on the circuit board as shown in photo frame #5. Now position the 1” x 1” copper clad
circuit board (foil side up) 1/8” in front of the rear main circuit board mounting screw; and 1/16” from the right edge.
Mark the two front corners of the 1” x 1” copper clad circuit board on the main circuit board as shown in photo frame
#5. Remove the 1” x 1” board and relay, and set aside. Remove the two mounting screws, and main circuit board /
heat sink assy. from the enclosure.
4, Reposition on the main circuit board / heat sink assy. the 1” x 1” circuit board and relay. (Remember, the two lone
pins of the relay are to the rear) Now position the four transistor / pill strips (foil side up) as shown in photo frame #6.
It is important to read the following in its entirety, as the next process must be performed in one fluid action.
Once you get a good feel where everything needs to be located, mix some 5 minute epoxy where the final amount of
the two mixed components is about the diameter of a nickel and 3/16” high. The previous statement for the quantity
is just for reference, but should be enough to perform the next process. Once the epoxy is good and mixed, remove
the previously positioned components one a time starting with the first pill strip. Apply a light coating of epoxy to the
bottom, reposition right back where it came from. Do the same with the rest of the pill strips. Now mount the 1” x 1”
circuit board at its assigned location. Take the rest of the mixed epoxy and apply to the relay (The side opposite the
pins) and place at its marked position. Now go back and reposition any of the components that may have shifted.
As the epoxy sets, remove any extra that may have oozed over the edge at the rear of the relay.
Take a break and have a cup of coffee.
Page 4
Step 3
Parts Needed: Circuit board / heat sink assy.
RF Power Transistors (TR1, TR2, & TR3)
Ferrite Transformer Cores (T1, T2, T3, & T4)
1 ea. 9-1/2” length #14 Silver/Teflon wire (WIRE-1)
150 pf Silver Dipped Mica Capacitor (C17)
6ea. #4-40 x ¼” Socket machine screws
Tools Needed: 3/32” T-handle Allen wrench (Regular Allen wrench may be used)
Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Scrap circuit board material (Included in hardware kit)
Heat sink lubricant (Included in hardware kit)
X-acto knife or Olfa knife
Small 1/8” blade straight slot screw driver (Jewelers type is best)
Procedure:
1, Make sure that all three transistor mounting wells are clear of epoxy ooze (Trim with X-acto knife if needed) and
clean heat sink in the transistor wells with a Q-tip to remove any debris. Trim the corner of the plastic bag containing
the heat sink lubricant. Squeeze equal amounts of lubricant into the center of each transistor wells until all of the
lubricant is used. Align the transistor marked SD1446/2SC2879 (TR1) over the front well shown in photo frame #7.
Notice that the collector leg of the transistor has a bevel cut in it, and should be pointing to the right. Firmly push
straight down on top of the transistor until it is fully and completely seated. Be very careful not to bend the mounting
tabs of the transistor as they are made of soft metal. Seat the other two transistors marked 2SC2879 (TR2 & TR3) in
the last two wells with their collector legs pointing to the rear. When finished, the assy. should look just like photo
frame #7.
2, This is another point at which we need to be very careful, as we don’t want to twist off the head of any of the #4-40
socket machine screws. With all the transistors fully seated, thread the machine screws through the mounting tabs of
each of the transistors and into the heat sink. Just make them good and snug, not super tight. Believe me; you don’t
want to have to deal with drilling out a steel #4 screw mounted in aluminum. This is supposed to be fun!
If you used a #40 drill bit when boring the transistor mounting holes, the #4-40 screws will self thread. However if
there is undo resistance, back off a couple turns and them continue the self threading process. Once all the transistors
are mounted, bend the legs as instructed in photo frame #8.
3, Gentlemen, heat up your soldering irons! We will presume you have good soldering skills, so we will not get into a
soldering lesson. However, if there are any questions, please give us a call or Email. Solder the emitter legs of each
transistor to the main circuit board assy. as shown in photo frame #9. Take the 1-1/4” long ferrite transformer core
(T4) and look at each end, you will notice that on one of the ends, the two brass tubes that comprise the primary
winding is not connected. The non connected side from now on will be referred to as the “front” of this and all
transformers. On the front of the transformer you will also notice that the two solder pads may narrow on one side,
this will be considered the bottom edge and also the side that will be soldered to the pill strips. See photo frame #10.
With the front of the 1-1/4” transformer facing you and the bottom edge down, insert the 9-1/2” long 14 gage wire in
the front left tube so that it protrudes out the rear of the transformer 3/4 of an inch. While maintaining the 3/4" length
out the rear, insert the other end of the wire into the right tube and pull through until the loop that is formed is snug
against the front face of the transformer. Continuing with this end of the wire, insert into the rear of the left tube on
top of the first wire and pull through. Again snug the loop that is formed against the rear face of the transformer. As
the wire exits the front of the transformer it should still be on top of the first. As you probably suspected, we got one
more tunnel ride. Take the wire and insert into the right tube still staying on top of the first winding all the way
through and pull tight from the rear. At this point you should have 3/4" sticking out the bottom-rear of the left tube
and a little more than an inch out the top-rear of the right as shown in photo frame #11.
Page 5
4, On the 3/4" lead, remove 1/4" of insulation by scoring all the way around the wire with an X-acto knife and sliding
off the insulation. Trim the other lead in the same manner, however in this case we want to leave 3/4 of an inch of
insulation on the lead. Looking at the front of the transformer with the bottom edge down and the leads pointing
away from you, bend the short lead to the left and the long lead up. Set the front end of the transformer with the
bottom edge down on the rear most pill strip. Place the scrap piece circuit board material under the rear of the
transformer to keep it level. Adjust the transformer so that the separation cut in the pill strip is in the center between
the two solder pads of the transformer and the wire that was bent to the left is about 1/16 of an inch away from the
relay housing. See photo frame #12. Carefully solder each of the transformer solder pads to the pill strip pads on
which they sit by starting on one side and then moving to the next, while doing so let the collector legs of each of the
two power transistors become soldered to the pill strip pads as well. Use enough solder as to create a good filet that
will help support the transformer. See photo frame #13.
5, Solder the short transformer lead that is bent to the left to the main circuit board by holding the wire down with the
tip of the soldering iron, adding solder, and holding the wire in position with the small screw driver while the solder
solidifies. See photo frame #14. Remove the scrap circuit board material and set aside.
Take the transformer lead that’s pointing up and bend to the left and place behind the front right relay pin, leave about
a 1/4" of non-insolated wire hanging over the edge of the relay housing. (Refer to photo frame #15) Fold the relay pin
to the rear and over the wire and solder. Trim the excess wire just left of the relay pin as shown in photo frame #15.
6, Take the 150 pf silver dipped mica capacitor (C17) and bend the leads as shown in photo frame # 16. Position and
solder the capacitor to the main circuit board as shown in photo frame #17. Trim the remaining lead of the capacitor
3/16 above the transformer wire that’s attached to the relay. Bend this lead around the transformer wire and solder as
shown in photo frame #18.
7, Rotate the assy. 180º on the work surface. Take one of the 1/2" long ferrite transformer cores which will become
(T3) and set the front end of the transformer with the bottom edge down on the pill strip. Place the scrap piece circuit
board material under the rear of the transformer to keep it level. Adjust the transformer so that the separation cut in
the pill strip is in the center between the two solder pads of the transformer and the bottom front edge just touches the
base legs of the two transistors. Carefully solder each of the transformer solder pads to the pill strip pads on which
they sit by starting on one side and then moving to the next, while doing so let the base legs of each of the two power
transistors become soldered to the pill strip pads as well. Use enough solder as to create a good filet that will help
support the transformer. See photo frame #19. Remove the scrap circuit board material and set aside.
8, Rotate the assy. to the right 90º on the work surface. Take the 1” long ferrite transformer core (T2) and set the
front end of the transformer with the bottom edge down on the rear pill strip of the single SD1446 transistor (TR1).
Place the scrap piece circuit board material under the rear of the transformer to keep it level. Adjust the transformer
so that the separation cut in the pill strip is in the center between the two solder pads of the transformer and the
bottom front edge is centered the full length of the pill strip. Carefully solder each of the transformer solder pads to
the pill strip pads on which they sit by starting on one side and then moving to the next, while doing so let the
collector leg of the power transistor become soldered to the pill strip pad as well. Use enough solder as to create a
good filet that will help support the transformer. See photo frame #20. Remove the scrap circuit board and set aside.
9, Rotate the assy. to the right 180º on the work surface. Take the remaining 1/2" long ferrite transformer core (T1)
and set the front end of the transformer with the bottom edge down on the remaining pill strip of the single SD1446
transistor (TR1). Place the scrap piece circuit board material under the rear of the transformer to keep it level. Adjust
the transformer so that the separation cut in the pill strip is in the center between the two solder pads of the
transformer and the bottom front edge is centered the full length of the pill strip. Carefully solder each of the
transformer solder pads to the pill strip pads on which they sit by starting on one side and then moving to the next,
while doing so let the base leg of the power transistor become soldered to the pill strip pad as well. Use enough
solder as to create a good filet that will help support the transformer. See photo frame #21. Remove the scrap circuit
board material and set aside. I know I keep repeating myself, but it’s just so we don’t make any mistakes.
Page 6
Step 4
Parts Needed: Circuit board / heat sink assy.
3 ea. 10Ω 1/2W carbon film resistor (R3, R6, & R7)
3 ea. 120pf @ 500V Silver Dipped Mica Capacitor (C10, C15 & C16)
3 ea. 1000pf / 500V Silver Dipped Mica Capacitor (C2, C3, & C4)
4 ea. 0.1uf Ceramic Disc Capacitor (C5, C6, C7, & C8)
1 ea. 0.03 @ 500V silver dipped mica capacitor (C20)
1 ea. 3A / 1000V PIV Silicon Rectifier (D1) (Large)
1 ea. 1A / 1000V PIV Silicon Rectifier (D2) (Small)
2 ea. 1/2" x 1/2" ferrite core (CHK5, & CHK7)
1 ea. 9” length of #16 Silver/Teflon wire (WIRE-2)
1 ea. 7” length of #16 Silver/Teflon wire (WIRE-2)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Take the three 10Ω 1/2W resistors, bend and trim as shown in photo frame #22.
Solder these resistors in place as shown in photo frame #23.
2, Take the three 120pf capacitors, bend and trim as shown in photo frame #24.
Solder these capacitors in place as shown in photo frame #25.
3, Take the three 1000pf capacitors, bend and trim as shown in photo frame #26.
Solder these capacitors as shown in photo frame #27.
4, Take the four 0.1uf capacitors, bend and trim as shown in photo frame #28.
Solder these capacitors as shown in photo frame #29.
5, Take the 0.03uf capacitor, bend and trim as shown in photo frame #30.
Solder this capacitor as shown in photo frame #31.
6, Take the 9” length of #16 wire and make 3 loops through one of the 1/2” x 1/2" ferrite cores (CHK5), strip ends
and bend as shown in photo frame #32. Solder bent end to the middle of the back side of T2, and the straight end to
the 1” x 1” circuit board as shown in photo frame #33.
7, Take the 7” length of #16 wire and make 3 loops through the other 1/2” x 1/2" ferrite core (CHK7), strip ends as
shown in photo frame #34. Solder the 7/8” end to the center of the rear of T4 as shown in photo frame #35. Bend and
solder the other end to the center inside edge of the 1” x 1” circuit board as shown in photo frame #36.
8, Take the 3A silicon rectifier, bend and trim as shown in photo frame #37.
Solder in place as shown in photo frame #38
9, Take the 1A silicon rectifier and place on the relay in front of the rear two pins as shown in photo frame #39.
Fold each of the pins forward over the legs of the rectifier as shown in photo frame #40. Solder in place as shown in
photo frame #41. Bend the left lead (Anode) as shown in photo frame #42. Bend and trim the right lead (Cathode) as
shown in photo frame #43.
Page 7
Step 5
Parts Needed: Circuit board / heat sink assy.
Switching Transistor (TR4)
Glass Signal Diode (D3)
22uf Electrolytic Capacitor (C18)
22pf Ceramic Disc Capacitor (C19)
1 ea. 9” length of #16 Silver/Teflon wire (WIRE-2)
1 ea. 8” length of #16 Silver/Teflon wire (WIRE-2)
1 ea. Trim Capacitor (VC1)
2 ea. 4.7Ω 2W Carbon Film Resistor (R4, & R5)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Take the switching transistor and bend legs as shown in photo frame #44. Attach the 22uf electrolytic capacitor to
the switching transistor as shown in photo frame #45, observe polarity. Attach the glass signal diode to the
transistor/capacitor assy. as shown in photo frame #46, observe polarity. Attach the 22pf ceramic disc capacitor as
shown in photo frame #47. Solder and trim as shown in photo frame #48, do not solder the full length of the twisted
leads as they will need to be bent in the following procedures.
2, Take the leg of the T/R relay drive assy. that has the emitter of the transistor, the negative of the capacitor, and the
anode of the diode twisted together, and solder to the main circuit board as shown in photo frame #49. Take the leg
of the T/R relay drive assy. that has the collector of the transistor, and the positive of the capacitor twisted together,
and wrap around the anode lead of D2 at the bend as shown in photo frame #50. Solder and trim as shown in photo
frame #51. Leave the unattached lead of 22pf free for now, as it will be attached later.
3, Take the 9” length of #16 Silver/Teflon wire and trim 1/4"of insulation from one end only. With the circuit board /
heat sink assy. oriented in front of you with the relay to the rear, insert the non-stripped end of the wire into the left
tube of transformer (T3), bend down the stripped end and solder to the main board as viewed in photo frame #52.
Thread the wire through the right tube from the rear and back through the left tube from the front. Keep doing this
until three (3) winding turns are made, always keeping the current turn on top of the previous as shown in photo frame
#53.
4, Take and prepare the trim capacitor as shown in photo frame #54. Solder the trim capacitor to the main circuit
board in place as shown in photo frame #55A & 55B. Take the loose wire from transformer (T3), strip insulation and
insert into the top tab of trim capacitor, bend over and trim as shown in photo frame #56, Do Not Solder.
5, Take the 8” length of #16 Silver/Teflon wire and trim 1/4"of insulation from one end only. Insert the non-stripped
end of the wire into the left tube of transformer (T2), bend down the stripped end and solder to the main board as
viewed in photo frame #57. Wind the transformer in the same manner as you did with transformer (T3), but this time
we only need two (2) winding turns as shown in photo frame #58.
6, Prepare the two 4.7Ω resistors as shown in photo frame #59. Attach and solder the resistor assy. to the top tab of
the trim capacitor as shown in photo frame #60, (Notice the orientation of the resistors to chose the correct lead to
solder). Strip the insulation and wrap the remaining lead of the resistor assy. around the wire exiting transformer (T2)
As shown in photo frame #61. Solder and trim as shown in photo frame #62.
Page 8
Step 6
Parts Needed: Circuit board / heat sink assy.
1 ea. 13” length of #20 Silver/Teflon wire (WIRE-3)
1ea. 100pf Silver Dipped Mica Capacitor (C1)
2 ea. 1/4" x 1/2" Ferrite Core (CHK4, & CHK6)
2 ea. 4-3/4” length of #20 Silver/Teflon wire (WIRE-3)
2 ea. 100Ω 2W Carbon Film Resistor (R8, & R9)
2 ea. 0.01uf Ceramic Disc Capacitor (C11, & C12)
1 ea. 1000pf / 500V Silver Dipped Mica Capacitor (C9)
1 ea. 820pf / 500V Silver Dipped Mica Capacitor (C14)
1 ea. 330pf Silver Dipped Mica Capacitor (C13)
1 ea. 1” length of #16 Silver/Teflon wire (WIRE-2)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Take the 13” length of Silver/Teflon wire and trim 1/4"of insulation from one end only. Insert the non-stripped end
of the wire into the right tube of transformer (T1), bend down the stripped end and solder to the main board as viewed
in photo frame #63. Thread the wire through the left tube from the rear and back through the right tube from the
front. Keep doing this until five (5) winding turns are made, always try to keep the current turn on top of the
previous, however if the windings bundle-up it’s OK, see photo frame #64. Prepare the 100pf capacitor as shown in
photo frame #65. Solder the capacitor to the main circuit board as shown in photo frame #66. Wrap the free
capacitor lead around the stripped wire that exits transformer (T1). Solder and trim capacitor lead, but Do Not trim
the transformer wire as shown in photo frame #67.
2, Take the two 4-3/4” lengths of Silver/Teflon wire and prepare both ferrite cores (CHK4, & CHK6) as shown in
photo frame #68. Take the prepared ferrite core CHK4, and solder the longer lead to transformer (T1), and the shorter
3/4" long lead to the main circuit board as shown in photo frame #69. Take the prepared ferrite core CHK6, and
solder the longer lead to transformer (T3), and the shorter 3/4" long lead to the main circuit board as shown in photo
frame #70.
3, Prepare two (2) harmonic suppression feed-back circuits by using the 100Ω resistors, the 0.01uf capacitors and
following the instructions in photo frame #71. The next process can be a little tricky to hold with your fingers, so we
recommend using a good pair of tweezers. Solder the capacitor end of the feed-back circuit to the forward pill strip,
and then bend the leads as necessary to reach over to the other pill strip. It’s a good idea to line things up before
doing any soldering. Please see photo frame #72A, 72B, & 72C for component placement.
4, Take the 1000pf Silver Dipped Mica Capacitor (C9) and trim both leads down to 1/4". Solder to the front of
transformer T2 as shown in photo frame #73.
5, Take the 820pf Silver Dipped Mica Capacitor (C14) and trim both leads down to 1/4". Solder to the front of
transformer T4 as shown in photo frame #74.
6, Take the 330pf Silver Dipped Mica Capacitor (C13) and trim both leads down to 1/4". Solder to the front of
transformer T3 as shown in photo frame #75.
7, Take the 1” piece of #16 wire and strip 1/2" of insulation from it. Place the stripped portion of the wire on the relay
behind the pins as shown in photo frame #76. Bend pins back, over, and around the wire, solder and trim.
See photo frame #77. Page 9
Step 7
Parts Needed: Circuit board / heat sink assy.
Bottom half of aluminum enclosure (Cabinet)
2ea. Pan Head sheet metal screws
1/4" Stereo Phone Jack (Conn3)
2 ea. 1-3/8” length of #16 Silver/Teflon wire (WIRE-2)
SPST Switch (SW1)
LED Mounting Clip (SCK1)
LED Assy. (D4)
100Ω 2W Potentiometer (VR1)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Mount the 1/4" phone jack as shown in photo frame #78, position so that the solder lugs are clear of the enclosure.
2, Carefully mount circuit board / heat sink assy. in the enclosure using the two sheet metal screws that were used in
step 2, procedure 2, process 3. Please see photo frame #79. Bend the two solder lugs down against main circuit board
assy. as shown in photo frame #80. Solder these two lugs to the main circuit board as shown in photo frame #81.
3, Insert the unconnected lead of the 22pf capacitor (C19) into the center conductor of the left SO239 RF connector
(Conn2) as shown in photo frame #82, trim if necessary. Take one of the 1-3/8” lengths of #16 wire and remove 1/4"
of insulation from both ends, insert one end of this wire into the center conductor of the left SO239 along with the
lead from the capacitor and solder as shown in photo frame #83. Bend the free end of the wire and place as shown in
photo frame #84. Solder and trim as shown in photo frame #85.
4, Take the remaining 1-3/8” length of #16 wire and remove 1/4" of insulation from both ends, insert one end of this
wire into the center conductor of the right SO239 RF connector (Conn1). Solder as shown in photo frame #86.
Bend the free end of the wire and place as shown in photo frame #87. Solder and trim as shown in photo frame #88.
5, Prepare the SPST switch as shown in photo frame #89. Mount the switch as shown in photo frame #90.
6, Insert the LED mounting clip from the front of the enclosure as shown in photo frame #91.
Prepare LED assy. as shown in photo frame #92. Insert LED assy. into LED clip as shown in photo frame #93.
7, Prepare the 100Ω potentiometer as shown in photo frame #94. Install potentiometer as shown in photo frame #95.
See photo frame #96 to install control knob.
Page 10
Step 8
Parts Needed: Amplifier Assy.
1 ea. 4” length of #20 hook-up wire. (WIRE-4)
1 ea. 12” length of #20 hook-up wire. (WIRE-4)
1 ea. 9” length of #20 hook-up wire. (WIRE-5)
1 ea. 11” length of #20 hook-up wire. (WIRE-5)
1/4" x 1/2" Ferrite Core (CHK2)
1 ea. 100Ω 2W Carbon Film Resistor (R2)
1 ea. 4.7Ω 2W Carbon Film Resistor (R1)
1 ea. 8-1/2” length of RG-316 Coax Cable (COAX)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
X-acto Knife
Procedure:
1, Take the black lead of the LED assy. and solder it to the main circuit board as shown in photo frame #97.
Now take the red lead of the LED assy. as shown in photo frame #98 and insert it into the top solder tab of the switch,
wrap around tab, but Do Not Solder Yet.
2, Take the 4” length of hook-up wire and remove 1/4" of insulation from each end. Solder one end of this wire to the
loop that was formed in the cathode lead of the rectifier (D2) as shown in photo frame #99.
Please see photo frame #100 to identify the solder lugs of the 1/4" phone jack that is used with the optional remote.
As shown in photo frame #101, take the free end of the wire that was soldered to D2, and attach it to the solder lug of
the phone jack that will connect to the “Ring” of the phone plug when inserted, Do Not Solder Yet.
Take the 12” length of hook-up wire and remove 1/4" of insulation from each end. Attach one end of this wire to the
same solder tab of the phone jack that the last wire was attached to, solder as shown in photo frame # 102. Route
wire down, and along the heat sink as shown in photo frame #103. Solder this wire to the top tab of the switch along
with the lead from the LED assy. NOTE: When soldering wires to the switch, make sure that it is in the “Off” (Lever
down) position. Also solder wires as quickly as possible, as excess heat on solder tabs can damage the switch.
3, Take the 9” length of hook-up wire and the ferrite core, prepare as shown in photo frame #104. Solder the shorter
of the leads to the 1” x 1” circuit board, and attach the other end to the bottom solder tab of the switch, Do Not Solder
Yet as shown in photo frame #105. Take the 11” length of hook-up wire and remove 1/4" of insulation from each
end. Attach one end of the wire to the bottom solder tab of the switch along with the wire from CHK2 and solder as
shown in photo frame #106. Take the other end of this wire and solder it to the lug on the 1/4" phone jack that will
connect to the “Tip” of the phone plug when inserted, see photo frame #107.
4, Install the 100Ω resistor (R2) as shown in photo frame #108. Install the 4.7Ω resistor (R1) as shown in photo
frame #109.
5, Prepare the coax cable (COAX) as shown in photo frame #110 & #111. Install coax cable by taking the end that is
5 inches from the exposed braid and inserting the center conductor though and bending around the middle tab of VR1,
solder in place as shown in photo frame #112. Take the center conductor of the opposite end of the coax and wrap it
around the remaining pin of the T/R relay (RLY1), solder and trim as shown in photo frame #113. Position the
exposed braid portion of the coax and solder to the main circuit board as shown in photo frame #114.
Page 11
Step 9
Parts Needed: Amplifier Assy.
Rubber Grommet
1 ea. 19” length of #12 Power Cable (WIRE-6)
1 ea. 1/2" x 1/2" Ferrite Core (CHK1)
4 ea. Rubber Feet
Enclosure Cover
3-1/4” Fan Assy. (FAN1)
3-1/4” Fan Guard (FG1)
4 ea. #8 32 x 3/4" Pan Head Machine Screw
4 ea. #8 32 TPI Machine Nut
3 ea. #8 Lock Washer
1 ea. #6 Solder Lug
1 ea. 1/4" x 1/2" Ferrite Core (CHK3)
Tools Needed: Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Install the rubber grommet as shown in photo frame #115. Take the 19” power cable and cut from one end
separating the two conductors for about four (4) inches. Take the black 4” leg and trim off 2-1/2” of it.
Take the red 4” leg and make one loop through the 1/2" x 1/2" ferrite core. Trim 1/2" of insulation from each leg as
shown in photo frame #116. Slide the opposite end of the power cord through the grommet from the inside, and
solder the black wire to the main circuit board as shown in photo frame #117. Solder red wire to the 1” x 1” circuit
board as shown in photo frame #118. Turn unit over and attach rubber feet to bottom of enclosure, one at each corner.
2, Take the fan assy. and remove the 3-pin connector, by cutting the wires as close to the connector as possible.
Completely un-twist wires, and trim off white wire as shown in photo frame #119. Trim back black wire as shown in
photo frame #120. Take the solder lug and bend the inner tangs outward so that one of the #8 machine screws can be
threaded through it. As shown in photo frame #121. Remove 1/4" of insulation from the black wire and solder to the
lug as shown in photo frame #122. Take the red wire and loop it through the ferrite core three (3) times, and then
through the fan mounting hole as shown in photo frame #123.
3, Looking at the inside of the enclosure cover with the cooling vent slots to the right, mount the fan assy. on the
inside, and the fan guard on the outside using the #8 machine screws, lock washers and nuts. When aligning the fan,
make sure that CHK3 is at the lower left, and that the fan grounding lug that will be used as a lock washer is at the
upper right as shown in photo frame #124. After installation, the fan guard should look as that pictured in photo frame
#125. Set the assembled cover to the side, it’s time to test and calibrate your new amplifier.
Page 12
Step 10
Parts Needed: Amplifier Assy.
Tools Needed: -12~20VDC power supply capable of supplying a constant current of 50 amps or better.
-10/11 meter transceiver with a “Dead Key” of 2~4 watts, and a peak envelope power no greater than
35 watts.
-Bird 43 watt meter with “peak reading upgrade” and 1000W/ 25~60 MHz. element or equivalent.
-Coax jumper with PL259 connectors at each end.
-1000W dummy load or antenna system with a good standing wave ratio (SWR).
The following are very useful but not necessary
-Sweep audio generator with an adaptor that mates with microphone plug on transceiver and has a
switch that keys transmitter. (We use a Wavetek model 188)
-100 MHz. oscilloscope (We use a Hitachi model V-1065)
-600 MHz. RF spectrum analyzer (We use a Hameg model HM5006
-Other RF taps and connectors as needed.
Procedure: Basic Calibration & Test
1, Connect amplifier as shown in photo frame #126.
2, Power up transceiver and select a mid-band frequency.
3, Keep amplifier “Off” and peak reading function of power meter “Off”.
4, With the transceiver keyed, and while saying the word “Audio” into the microphone, observe power meter for
forward deflection.
5, Turn amplifier “On”.
6, Key-up transceiver with no audio and slowly increase amplifier gain control to full clock-wise.
Observe power meter for forward deflection.
7, With the transceiver keyed, and while saying the word “Audio” into the microphone repeatedly at 1 second
intervals, adjust VC1 for minimum deflection. This is to mean that when you key-up the transceiver, and during
the one second pause where there is no audio, the meter will have a specific reading. But when there is audio, the
meter needle will deviate forward; adjust VC1 so that this deviation is at a minimum. This is the Root Mean
Square (RMS) output reading. Never operate where the needle swings backwards, as this is an indication of
transistor saturation.
8, Turn “On” the peak reading function of the meter. Key-up transceiver with audio and observe peak output.
9, See photo frame #127 for performance data.
Page 13
Step 11
Parts Needed: Amplifier Assy. / Enclosure Bottom
Enclosure Cover / Fan Assy.
12 ea. #6 32 x 1/4” Socket screw
Self Adhesive Label Sheet
Tools Needed: -7/64” T-handle Allen wrench (Regular Allen wrench may be used)
-Soldering Iron (A good 40~50 watt iron with a 1/16” chisel tip is best)
60/40 resin core solder or equiv. (We use Kester 63/37 @ .031”)
Procedure:
1, Take the enclosure cover/fan assy. and position as shown in photo frame #128. Cut back the fan power wire to the
length necessary to allow the wire to be soldered to the lug of the 1/4" phone jack that carries switched supply power.
Remove 1/4" of insulation and solder to the appropriate lug as shown in photo frame #128.
2, Position cover/fan assy. on lower chassis and install eight (8) #6 32 x 1/4” socket screws as shown in photo frame
#129. If bracket is to be used, install using four (4) #6 32 x 1/4” socket screws as shown in photo frame #130.
3, Take label sheet, cut apart, peel, and place on rear panel as shown in photo frame #131.
Congratulations, you are now the proud owner of a high quality
high performance HF linear amplifier that you built yourself!
Page

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continued in 1X2 "part3"

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parts list and build instructions are listed on 1X2 schematics "page 5"
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continued in 1X2 "part 2"