P440 UHF Preamp Parts List:

The preamp's input is closest to the coil L1.

C1 - 2pF (2) ceramic disc
C2 - 5pF (5) ceramic disc
C3 - 2pF (2) ceramic disc
C4 - 5pF (5) ceramic disc
C5 - 100pF (101) ceramic disc
C6 - 1uF (105) (yellow) monolithic ceramic
C7 - .01uF (103) (blue) monolithic ceramic

R1 - 100k - 5% (brown - black - yellow - gold)
R2 - 470 ohm - 5% (yellow - violet - brown - gold)
Resistors are 1/6 watt.

L1 - 1.25 inch - #24 AWG copper magnet wire.  It is installed by bending it in a U shape.
Tin the ends by burning the insulation off with a soldering iron.  This is done by melting 
solder around the wire.  It takes time, but the insulation will eventually burn off, leaving 
a nicely tinned wire.  Tin a distance of approximately 1/8 inch for insertion into the 
printed circuit board.  DO NOT trim any wire from the length, and insert the coil into the 
silkscreened side of the board with very little sticking through.  Solder the wire into the 
holes, and trim any excess lead length (on the soldered side) as necessary.

Adjusting the coil is done with a dental tool or other hook type of instrument.  Put the 
hook end of the tool into the U and start winding - exact direction doesn't matter.  I go
in a clockwise direction. At approximately two complete turns, you reach the center of the 
Amateur UHF band.  Adjust the wraps to tune the preamp to your desired frequency, or 
best noise figure if you own such equipment.

Adjusting the coil for maximum gain usually results in a little more than 14 dB of gain, 
2 dB noise figure, and around 16 to 18 dB of input return loss (a match of 1.29 : 1 VSWR).


LP - Printed circuit choke (part of the printed circuit board traces)

Q1 - 2SC2570A Transistor

J1 & J2 - SMA female board mount connectors

Masters Communications P440 circuit board