P25 Ham repeater ?

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phido
Posts: 27
Joined: Thu Oct 06, 2011 2:41 pm
What radios do you own?: XTL5000,XTS5000M3,APX7000XE

P25 Ham repeater ?

Post by phido »

Our group would like to put up a P25 VHF ham repeater and since a Quantar is out of our reach because of price and Range 1 availability
We were wondering if putting 2 PM1500's or XTL5000's together using a ham repeater controller would work. Or is there another option
Thanks Jim K4AJM
jhooten
Posts: 297
Joined: Sat Mar 06, 2004 12:58 pm

Re: P25 Ham repeater ?

Post by jhooten »

Using a subscriber unit for a receiver, taking the decoded audio out then feeding the audio into another subscriber unit as the repeater transmitter?

It will work but not well. The conversion from digital to analog then analog back to digital adds a slight delay to the audio. The multiple conversions causes some loss of audio quality.

If you tap the digital signal from the receiver before it is decoded and feed it into the transmit chain after the A/D converter before the modulator it will work better but you will loose the ability to do mixed P25 and analog.

Not to mention that by the time you buy two XTLs and the controller you are right back up in the price range of a Quantar.

Look for a used Kenwood P25 repeater. They may be a tad cheaper.
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phido
Posts: 27
Joined: Thu Oct 06, 2011 2:41 pm
What radios do you own?: XTL5000,XTS5000M3,APX7000XE

Re: P25 Ham repeater ?

Post by phido »

Thanks for your reply.
First I have been looking for a good Range 1 VHF quantar for a year with no luck and I have a PM1500 and an XTL 5000 in stock as
well as a controller. I know the quality would suffer some, a Quantar's P25 audio is hard to beat But do you think it would be that bad ?
I have not used A Kenwood but I have used an Icom D-Star and I wasn't impressed. Jim
jhooten
Posts: 297
Joined: Sat Mar 06, 2004 12:58 pm

Re: P25 Ham repeater ?

Post by jhooten »

Our local tech spent so much time at the tower site tweaking the set up (Astro Spectras) he asked that a kitchen and full bathroom be installed at the site. The antique Micor repeater is back at the site and working nicely. The club is talking about going to D-Star instead of P25. It seems Icom has some sort of subsidy program going to get more of their stuff on the air. I'm not buying D-Star when I have plenty of good P25 stuff.
tvsjr
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Joined: Fri Nov 28, 2003 9:46 am

Re: P25 Ham repeater ?

Post by tvsjr »

Double-vocoded audio sounds like warmed-over ass in the best of circumstances. Get a Quantar (there are plenty available, if you are willing to drop the coin) or look into one of the repeaters from another vendor - Daniels, Kenwood, Icom, etc.
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phido
Posts: 27
Joined: Thu Oct 06, 2011 2:41 pm
What radios do you own?: XTL5000,XTS5000M3,APX7000XE

Re: P25 Ham repeater ?

Post by phido »

Thanks to all for the advise, we have seen the light. I have been looking for a range 1 Quantar for a while with no luck but then one popped up
on Pbay and I took the plunge. We will see if I made the right move. I hope you guys will help this Quantar nubee on this new adventure.
Thanks Jim
KB2ZTX
was jsikora
Posts: 269
Joined: Wed Jun 11, 2003 9:38 am

Re: P25 Ham repeater ?

Post by KB2ZTX »

I have used suitcase P25 repeaters that are just that, 2 XTL mobiles with a repeater controller. They are fine as a tactical repeater but you loose many of the P25 functions like ID and such. Again ideal for what it was used for. Im sure the Quantar will be the ideal setup for the hill top.
KB2ZTX
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W1HVN
Posts: 417
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What radios do you own?: MX300 w/DVP

Re: P25 Ham repeater ?

Post by W1HVN »

Prior to putting in our Quantar we for a long time ran a pair of GM300s which removed filtering and passed the digital stream and analog audio. See the thread in this forum on it. The subscriber radio does the decoding of pl and nac. A controller wws developed to emit a callsign with delay for activity. It worked remarkably well. A MSF can do the same if filtering is removed so the entire spectrum of the digital stream is passed.

I would do that way before double vocoding.

Then down tbe road as the Q becomes more attainable then you can move to it.

I highly recommend this as your alternative.

"Digital capable repeater using maxtrac specs" is the sticky on this forum...

Good Luck
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