20 Meter Band VCXO Kit (for Universal Receiver)

The parts in this VCXO Kit are designed for 20 Meter reception from approximately 14039 to 14063 KHz.
The Kit includes the following parts/items:

L1 FT37-61 14T#27Green
L2 T37-2 34T#30Red
L3 FT37-61 15T#27Green
T1 T37-2 30T#30Red::4T#27Green
C20,21 120pF NPO marked 121
C6 22pF NPO ...or... 33pF NPO
C8 22pF NPO ...or... 12pF NPO
C14,15,16,17 680pF NPO marked 681
X5 22.118 MHz VCXO Crystal
X1,2,3,4 Matched 8.064 (filter center ~ 8,061.7 Khz)
26 inches Green #27 magnet Wire
40 inches Red #30 magnet Wire

Install all the below parts in the order given.

_____C6: Install 22pF or 33pF VCXO Feedback Capacitor
_____C8: Install 22pF or 12pF VCXO Feedback Capacitor

_____C14,15,16,17: Install 680pF Capacitors - establish crystal filter bandwidth

_____C20,21: Install 120pF BFO Capacitors; because of 0.1 inch lead spaing, install in the left and center holes

Wind and install all Toroid Inductors.  Wind all wires on the toroids clockwise.


_____T1: Install RF Bandpass Transformer.

   Cut 19" of #30 red wire and tightly wind 30 turns on T1, a Red T37-2 toroid
   Cut 6" of #27 green wire and wind 4 turns
   Trim the #30 red wires to one inch.
   Trim the #27 green wires to half inch.

   Tin/solder the wire ends to the base of the toroid using a hot solder pencil.
   Spread the turns over most of the toroid.
   Install T1 with the #30 wires into the outside (upper and lower) holes on the PCB
   and the 4 turns #27 wire thru the center holes for T1.
   Pull the wires tight on the bottom of the PCB and solder, then trim.
   You should be able to straighten the toroid to match the outline on the PCB.

_____L1: Install Series tuned Inductor

   Cut 10" of #27 green wire and tightly wind 14 turns on L1, a black FT37-61 toroid
   Trim the #27 green wire to one half inch.
   Tin/solder the wire ends to the base of the toroid using a hot solder pencil.
   Spread the turns over most of the toroid.
   Install L1 on the PCB
   Pull the wires tight on the bottom of the PCB and solder, then trim.
   You should be able to straighten the toroid to match the outline on the PCB.

_____L2: Install Series Tuned VCXO Inductor (use holes A & C) DO NOT INSTALL IF USING A DDS

   Cut 20" of #30 red wire and tightly wind 34 turns on L2, a red T37-2 toroid
   Trim the #30 red wire to one half inch.
   Tin/solder the wire ends to the base of the toroid using a hot solder pencil.
   Spread the turns over most of the toroid.
   Install L2 on the PCB
   Pull the wires tight on the bottom of the PCB and solder, then trim.
   You should be able to straighten the toroid to match the outline on the PCB.

_____L3: Install Series Tuned BFO Inductor

   Cut 10" of #27 green wire and tightly wind 15 turns on L3, a black FT37-61 toroid
   Trim the #27 green wire to one half inch.
   Tin/solder the wire ends to the base of the toroid using a hot solder pencil.
   Spread the turns over most of the toroid.
   Install L3 on the PCB
   Pull the wires tight on the bottom of the PCB and solder, then trim.
   You should be able to straighten the toroid to match the outline on the PCB.

_____X5: Install 22.118 MHz VCXO Crystal

_____X1,2,3,4: Install 8.064 MHz IF Crystals


_____Experiment with C9 (customer supplied optional) to lower band freq limit; try 1pF, 2p2 or 3pF