Original Concept and Images by David A. Cooley N5XMT

Step 1: Remove Exciter PCB and change the following components
to the new values shown:

C430 = 68 pf 5% Silver-Mica

C447 = 10 pf NP0 Disk

C433 = 150 pf 5% Silver-Mica

C448 = 15 pf NP0 Disk

C434 = 120 pf 5% Silver-Mica

C451 = 4.7 pf NP0 Disk

C437 = 22 pf 5% Silver-Mica

C452 = 7.5 pf NP0 Disk

C439 = 22 pf 5% Silver-Mica

C455 = 3.9 pf NP0 Disk

C440 = 47 pf 5% Silver-Mica

C456 = 4.7 pf NP0 Disk

C443 = 15 pf 5% Silver-Mica

C458 = 1.5 pf NP0 Disk

C444 = 12 pf 5% Silver-Mica

C460 = 75 pf 5% Silver-Mica

R429 = 49 - 180 ohm 1/2 watt *see below for more information*

Step 2: Reinstall Exciter PCB and tune in accordance with
Motorola manual.

Exciter should produce approximately 100 mW. If
something other than 100 mW is needed for driving an outboard amplifier,
simply change the value of R429 to obtain the desired drive level.
Don't go below the original value for R429. Usually something around
49 to 75 ohms is needed to produce 200 mW which is needed to drive the
Toshiba SAV-15 properly.

The crystal formula is the same as the original highband formula. The crystal is just higher in fundamental and is not multiplied differently from the highband method. The formula of F/12 is still used, where F is the operating frequency in megahertz. The range of the crystal for an operating frequency of between 222 and 225 will be between 18.5 and 18.75 MHz respectively.

Example: 224.500 divided by 12 is 18.708333 MHz.

Page recreated by: Kevin K. Custer W3KKC

Copyright 1998 SEITS, N5XMT and W3KKC.