Philips FM828/U to 434 Mhz details?

[Don Wilschefski]

I am about to convert a U band 828 to work on 434 Mhz. Does anyone have
details of coil winding changes or component changes required to do this.
The information I have so far is a bit vague. I have full manuals so I
know the component values for each type etc.
If you could email the info to me or mail it, I will pay any costs etc.
My details are:
Don Wilschefski
14 Bramble St
North Rockhampton Qld 4701 Ph home 079 280065 work 079 361500
Fax 079 361414
Any details would be appreciated,

Regards,

Don Wilschefski

[gcol]

My complete file on FM-828 to Amateur Mods.

PHILLIPS FM-828
COMMERCIAL TWO WAY RADIO TRANSCEIVERS

RADIOS COME IN THREE MODELS;
FM-828 25 WATT MOBILE LOCAL OR REMOTE
CONTROL.
FM-814 50 WATT BASE STATION, RACK MOUNTED.
FM-880 25 WATT RADIO TELEPHONE, RACK
MOUNTED.

RADIOS COME IN 8 BANDS;
G BAND 32-40 MHz
E BAND 68-88 MHz
B BAND 132-157 MHz
A BAND 146-175 MHz
T BAND 403-420 MHz
U BAND 450-470 MHz
W1 BAND 470-500 MHz
W2 BAND 500-520 MHz

A BAND AND B BAND WORK ON 2 METRE AMATEUR BAND WITHOUT MODIFICATION

T BAND SHOULD WORK ON 70CM AMATEUR BAND WITHOUT MODIFICATION

U BAND CONVERSION TO 70CM AMATEUR BAND

RECEIVER;
NO MODS.

EXCITER;
ADD 1 pF ACCROSS C85 (VCO CONTROL).

PA;
ADD 3.3 pF CAP ACCROSS.C10.
ADD C25 3.3 pF ?

HARMONIC FILTER;
NO MODS.

W1 BAND CONVERSION TO 70CM AMATEUR BAND (NOT EASY)

RECEIVER;
ALL FRONT END TUNNED RX CIRCUITS NEED EXTRA INDUCTANCE. ADD ABOUT 1/2
TURN TO EACH SLUG.
LOCAL OSCILLATOR ALSO NEEDS MORE INDUCTANCE.

E BAND CONVERSION TO 6 METRE AMATEUR BAND

RECEIVER;
ADD 8.2 pF FROM HOT END OF EACH OF FOUR RF TUNNED CIRCUITS TO GROUND.
ADD EXTRA FERRITE SLUG TO EACH OF THE TWO LOCAL OSCILLATOR
MULTIPLIERS

EXCITER;
SEVERAL EXCITER CIRCUITS NEED EXTRA CAPACITANCE.

PA;
ADD THE FOLLOWING VALUE CERAMIC CAPACITORS ACCROSS THESE TRIMMER
CAPACITORS;
C20 ADD 22pF C23 ADD 56pF
C21 ADD 47pF C25 ADD 33pF
C22 ADD 22pF C24 ADD
1025/03/96pF

HARMONIC FILTER;
ADD 2 TURNS TO L1 & L3. ADD I TURN TO L2.

XTAL OSCILLATOR;
THE SERIES NETTING INDUCTOR NEEDS MORE TURNS, BUT THIS IS FIDDLY.
IT Might BE EASIER TO ADD MORE CAPACITANCE INSTEAD.
INCREASE C2, C6 & C11 (100 pF) TO 390 pF (EITHER BY PARALELLING
270 pF OR REPLACING CAPACITORS. IF CRYSTAL STILL WILL NOT OSCILLATE
ADD 22pF ACCROSS L1, L2 & L3 (OSC. COILS). IF STILL NO GO, REPLACE
THE 680(RESISTOR ACROSS THE XTAL WITH 1.5 k ohms

PHASE MODULATOR;
ADD 39pF ACROSS L4 & L5, OR REPLACE WITH 68 pF FOR EACH.
SOME RADIOS HAVE NEEDED VALUES AS HIGH AS 82 pF.

DIVIDER;
C45 & C46 NEED INCREASING FROM 47pF TO 100pF.
EITHER ADD 47pF OR RPLACE.
C44 & C47 NEED INCREASING FROM 33pF TO 47pF.

TUNED AMP;
INCREASE C54 FROM 1.8 pF TO 4.7 pF.
INCREASE C55 FROM 8.2 pF TO 15 pF.
INCREASE C61 FROM 6.8 pF TO 18 pF.
L6 MAY REQUIRE SOME EXTRA CAPACITANCE OR MAY NOT.

VCO;
PLACE FROM 3.3pF TO 6.8 pF ACROSS L8. TRY LOWER VALUE FIRST.

Thats all I've got on file at the moment. I have done one "U-band" conversion
already for a packet radio link and it worked out OK.

Andrew VK4CRT.