Philips FM-828E (E-band) Conversion Mods for 6 metre Amateur band

Created 13th November 2002, updated 14th December, 2012.

Modifications to a Philips model FM-828E to convert its operation from commercial VHF
low band to 6 metres HAM band This is a crystal controlled transceiver, which came in various
versions for different bands.
The FM-828 range is very popular for building repeaters, it has a high duty cycle and
is very reliable, being xtal locked is not a viable option for multi-channel mobile radio
therefore it is ideal for repeater use or a single channel mobile radio.

Crystal Oscillators.

C2 100pf add 180pf or replace with 270pf
C6 Same
C11 Same
Add 22pf across L1, L2 & L3
remove 680 ohm across crystal and replace with 1K5

Phase Modulators

C19 22pf add 39pf or replace with 68pf
C28 Same


C45 47pf add 47pf or replace with 100pf
C46 Same
C44 33pf add 12pf or replace with 47pf
C47 Same

Tuned Ampl

C54 1p8 add 3p3 or replace with 4p7
C55 8p2 add 6p8 or replace with 15pf
C61 6p8 add 10pf or replace with 18pf

Place 3p3 across L8

Power Amplifier
C21 trimmer and C26 in parallel. Add 47pf or replace with 82pf
C22 trimmer add 22pf
C23 trimmer add 56pf
C25 trimmer add 33pf
C24 trimmer add 10pf

Output harmonic filter
Add 2 turns to L1 and L3
Add 1 turn to L2

Add 8p2 across each RF front end tuned circuit : L1 to L4
Add slugs to oscillator doubler coils : L10 and L11


E-band Xtal calcs:

TX: f(carrier)  /8
Philips spec 9681 Type Q16A

for a 10.7 MHz IF

f(carrier) +10.7  /2
Philips spec 9691  Type Q16A

for a 10.8 MHz IF

f(carrier) +10.8  /2
Philips spec 9691  Type Q16A

NOTE: only licensed Amateur Radio operators can operate this modified equipment on assigned Amateur frequencies/bands.

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