Astro Digital Repeaters?

[Megahertz]

What is the name of the digital line of repeaters? Quantar? What is the least expensive (how much$) astro VHF and/or UHF repeater?

Can a regular repeater work on a Astro in the Digital mode?

Thanks in advance for anyones help.

[Astro Spectra]

The Quantar is currently the 'Astro' repeater. It can be programmed to repeat Astro transmissions after regenerating them. Note that they do not demodulate Astro transmission to audio you'll need another bit of hardware, the DIU, for that. Quantars are very nice but expensive beasts. How much you'd pay depends on your Motorola contract.

There are a number of ways to avoid big bucks in certain circumstances. For example I've seen 'portable' Astro repeaters built from Astro Spectras and Sabers. HOWEVER these configurations take a lot of knowledgeable engineering and strictly do not have FCC approval because of the modifications.

You don't always need an Astro repeater to carry Astro. A number of existing analog repeaters will happily repeat Astro transmissions with acceptable error rates. The key performance issues are flat audio response (no PL high pass in the TX) and no compression. A good signal strength into the repeater also helps! Lots of people will tell you this isn't possible but that's because there are lots of crappy sounding repeaters out there.

It's OK to have the normal transmitter pre-emphasis and receiver de-emphasis networks in place but slightly better Astro performance can be gained by turning off these off. If you do this you'll need to feed any PL, patch or other audio controller audio thru their own dedicated network(s).

Obviously it is better to use the real thing if you can!

Also note that such a repeater must be carrier operated....

<font size=-1>[ This Message was edited by: Astro Spectra on 2001-11-21 18:28 ]</font>

[Pj]

From what I have gathered, only the Quantar line will pass thru the repeater PROPERLY. In the digital mode, there is no PL/DPL, so normal repeater will not hear the signal. Thats why if you do not have a DVP etc chip, you do not hear the encryption. At the beginning of the signal, it tells the repeater to drop the pl, so that other non-encrypted radios do not hear the data.

There are ways around it, but getting a Quantar is the best bet. My PD is starting to look into a digital system, so as I learn more, ill pass it along.

[/\/\y 2 cents]

Sucks for you and your department...Digital Systems are a waste of money and 80% of the time do not work properly. What I am trying to say is that they are nice feature wise, but reliablity (getting out to your dispatcher) and audio quality need to be improved greatly. Go with a SmartNet II or Smartzone in Analog with Quantars operating in Analog mode, and when Motorola gets their Digital act together, Upgrade.

[aaron_tech]

You only will need a DIU if you are using some sort of console. If you are using the Quantar as a stand alone repeater with no console you won't need it. Also the quantar/quantro needs to use an astrotac comparator if you want to use more then one receive site. All this equipment is very expensive. If you are using more then one receive site you'll also need some way to get the digital audio to the astrotac comparater i.e. rf link, microwave or T-1 lines. I would not recommend the T-1 line we have had alot ofd problems with ours droppping out. I maintain an astro digital conventional simulcast system.

Aaron

[aaron_tech]

The digital from the big M works great most of the time, we have had unexplainable warble and garbeled audio. If you are looking into a new system there are several options. Use the quantars and the astro mobile but go analog with encryptian if want some security. Both those radios can be upgraded to accomodate astro in the future. Smartzone trunking is expensive also and in some case excessive. Depending on your needs a multicast or smulcast voted system may be the trick and will save you some money. Also for the record I was also factory trained on the EDACS system(before I started at my MSS, Ilearned who was rthe best), Their digital is knpw better. THe digital design is weak no matter who makes it.

Aaron