Mobile Repeaters and NAC's

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p1350m
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What radios do you own?: Tait, Quantar

Mobile Repeaters and NAC's

Post by p1350m »

In the way that a Quantar preserves all information like voice frames, Talkgroup ID's and Source ID's and for digital rebroadcast, but can change the Tx NAC from the Rx NAC, are there any mobile or portable products on the market that can perform the same function? I'm looking for a mobile repeater that has the ability to change the NAC but preserves all other data in a crossband application. I've looked at the Pyramid series. From the cable schematic it seems these units double vocode to achieve the result. I'm not sure about the Futurecom series though. Does anyone have any suggestions?
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wavetar
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Re: Mobile Repeaters and NAC's

Post by wavetar »

I've never done it, but the Tweaker software for the Futurecom DVRS definitely lets you set different unique TX & RX NAC codes. Also, the Futurecom unit does not double vocode, it works directly with the P25 data stream. Even encryption passes transparently through it.
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p1350m
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Posts: 18
Joined: Tue Sep 13, 2011 11:48 pm
What radios do you own?: Tait, Quantar

Re: Mobile Repeaters and NAC's

Post by p1350m »

That's good to know. Unfortunately finding documentation for the Futurecom DVRS is not easy. From previous posts on this forum it looks as though Futurecom is very strict as to who obtains their products and documents. Having said this, any purchase from say a well known action site, would be a gamble to actually landing a DVRS in the desired band.. unless someone here has the privilege of holding such information?
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515
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Re: Mobile Repeaters and NAC's

Post by 515 »

Those Futurecom DVRS units can vary quite a bit, as they are pretty much designed for a customer's specified frequency configuration. They often include filters to prevent the mobile radio and mobile repeater from de-sensing each other, so purchasing a used one would be risky. The filters might not re-tune to your frequencies, even though the mobile repeater might be able to be reprogrammed to them.

The Daniels/Codan units are nice too. They don't double-vocode and allow the NAC's to be programmed. But they're expensive and not quite as compact as the DVRS. I think their webpage had pictures of one of their repeaters mounted into a weatherproof enclosure on the roof of a fire truck. I'm not sure what options they have for interfacing their P25 repeater to a P25 mobile radio, though.
Jim202
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Re: Mobile Repeaters and NAC's

Post by Jim202 »

Futurecom is very strict as to who obtains their products and documents.[/quote]

The company is very tight with information due to their agreement with Motorola, but there is not a bunch of love between them. Seems every time Motorola makes a firmware change to their radios or a CPS upgrade, Futurecom has to go back and do an engineering game to get their repeater to play correctly again with the Motorola radios. When the next Motorola change comes out, they have to go through the process all over again.

Having had the displeasure to have had to play with these units, I would not even suggest that any agency consider using them. They are way too expensive for what you end up with. Then there are all the head aches that come with the Motorola software and firmware upgrades to keep the units playing well together. Trying to program the Motorola radios and the repeater so they play well together is a real pain in the lower posterior.

Been in this business for many years and I don't want anything to do with a radio system that even attempts to use this marriage between Futurecom repeater and the Motorola radios.

Jim
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