Need some help on the R1225... (GR1225 / RKR1225)

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Joined: Mon May 04, 2015 9:07 pm
What radios do you own?: Research Line through XTS/L

Need some help on the R1225... (GR1225 / RKR1225)

Post by YetAnotherMotoUser »

I have been tasked with the maintenance of an existing LTR system that has two dozen low power UHF R1225s in service.
Each one is followed by a 5w in - 100w out amplifier. I'm running out of good spare R1225s.

Does anybody have a extra copy of the paper manual for the HVN9054 RSS/CPS ? I believe that the manual is 68-80904Z93 but I could be mistaken.
I'd be happy with a PDF, but I don't think that Moto ever offered that. Did anybody ever scan one?
I'd like to acquire the paper manual for several reasons, however the main thing I'm after is the correct procedure for pairing a new PA deck to the R1225.
I've been told that the manual could not be ordered separately - that it was part of the HVN9054 software kit.
* * * NOTE TO MOD * * * I'm NOT asking for the RSS, it's already on the shop programming computer.

I have the PDF of the R1225 service manual (6880905Z53-O.pdf) from repeater-builder, but I'd like a paper copy.
Was there ever a later manual? Or is the -O the only one there was?
I'd also like to find a paper copy of the GR1225 manual (68-80904Z90).

Anybody have some known good low power PAs (or even complete low power UHF R1225s) on the shelf that they'd consider selling?

I've been told that a low power GM300 PA will work on a low power R1225.
The PA that I tried did 1 to 14 watts on the GM300 just fine, but only 1 to 4.5 watts on the R1225.
I suspect the issue is the pairing of the PA to the radio, and for that I need the book.

Other than removing the PA transistor from the high power PA, and jumpering the base to the collector
with a silver-mica capacitor what else has to be done to a high power GM300 PA to use it as a low power?
The other mod I've heard of is removing the PA transistor, jumpering base to collector with a length of braid and removing L2650 (couples B+ to the final collector.)

Another item: I'd like to know how to convince the R1225 control board that currently thinks it's a high power
that it's now a low power unit... i.e. make the necessary change so that the Radio Config screen in the RSS says low power instead of high power.
Is there a hidden key sequence that allows a change of a M44GRC control board to an M04GRC - i.e. a high power R1225 into a low power ?
Or how do I trigger a control board re-initialization? (i.e. convince the control board that it's a factory new board?)

Thanks in advance

(PS: I'm also looking for a good VHF low power R1225 PA for a personal project... )
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