Motorola PF849M Cellular Preamp

This forum is for the discussions targeted at converting various models of Motorola equipment to operate in the 900MHz Amateur Band.

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fineshot1
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Motorola PF849M Cellular Preamp

Post by fineshot1 »

I have had this old late 1980's cellular preamp around for many years and decided to bench it and see if I could retweek it from the mid 800mhz range to 902mhz and had success. Removing the cover exposes the guts and there is a small open type cavity with two coil adjustments to the left. After using the shop R2670 tracking generator on 902.9625 I was able to move both coils down in there range and get about 10 times out from what I put into the input. The external gain pot also has to be set for maximum. After tweeking it I tested it on a GE TMX9315 (with the 915mhz filters) which is pretty deaf at 902 (takes about .5uV just to open the squelch) and it only took .15uV into the preamp to get a full quiting signal into the old GE. This could of course be usefull in building a repeater which is why I thought I would share with you folks. It is pretty broad banded so you would have to insert a narrow rx filter between the preamp and receiver. I have seen these sold on ebay and on some other commercial equipment supplier web sites but they always seem to be cheaper on ebay. I have several pics I would like to post here but not too sure how to do that. Perhaps someone else could do that for me if I could send them. Thanks...Dan n2aym

PS - I think this preamp is actually made by celwave cause it very closely resembles the celwave line of preamps but could not find any celwave part numbers on it when I had it appart.
Last edited by fineshot1 on Wed Jan 25, 2006 2:48 am, edited 1 time in total.
fineshot1
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VE9MP
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What radios do you own?: FPP Railroad XTL9000 Cleancab

Post by VE9MP »

If you can email me the pics, i'll host them for you....

Nick@p25.ca
-----Nick-----

"I can trip some repeaters in Maine, but I'm not getting any audio into it, is there some type of tone frequency I use? If so do you know what one is for Maine?" - The SMT Machine
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VE9MP
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Posts: 429
Joined: Wed Jan 05, 2005 11:38 am
What radios do you own?: FPP Railroad XTL9000 Cleancab

Post by VE9MP »

Image

Image

Image
-----Nick-----

"I can trip some repeaters in Maine, but I'm not getting any audio into it, is there some type of tone frequency I use? If so do you know what one is for Maine?" - The SMT Machine
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