MRK AEGIS with Conventional Repeater

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smart6
Posts: 7
Joined: Fri Mar 07, 2003 8:59 pm

MRK AEGIS with Conventional Repeater

Post by smart6 »

Is it possible to use my MRK radio is AEGIS digital mode with a conventional repeater? I am currently trying to use it on a Motorola GR1225 repeater and every time I key up in AEGIS... it just spits out digital garbage. However, in simplex it works just fine. Do I need to change a setting on the repeater or the radio? Is there a repeater on the market I can get that will allow this to work?
motastro1
Posts: 17
Joined: Sun Dec 14, 2003 9:06 pm

Re: MRK AEGIS with Conventional Repeater

Post by motastro1 »

I ran into this awhile back and was told that there is an additional piece of equipment that needs to be added to the repeater to make it work with AEGIS radios. I can't remember what it is called though. I wanted to do this on a community repeater that I buy air space on. I wound up using voice inversion scrambling through the repeater instead and that works fine but it's not as secure as AEGIS.
mrk
Posts: 49
Joined: Wed Oct 11, 2006 1:12 pm

Re: MRK AEGIS with Conventional Repeater

Post by mrk »

Someone please correct me if I'm wrong, however, I'm pretty sure I understand this correctly. AEGIS is NOT encryption, nor voice inversion. AEGIS is a first generation digital voice codec. You would need a repeater running in AEGIS mode to use with the M-RK. It's the same as ASTRO (IMBE) or ProVoice (AMBE). In order to use a ProVoice enabled LPE-200, you have to run it through a ProVoice enabled repeater. A conventional repeater will just repeater what it "hears", which is digital modulation heard through an analog voice channel.
silverbk
Posts: 52
Joined: Sat Oct 23, 2004 6:05 pm

Re: MRK AEGIS with Conventional Repeater

Post by silverbk »

You are correct Aegis is just digital without any encryption, however with most Aegis radios encryption is possible by simply adding a system key. Ge had two flavors VGE and DES.

I'm sure a Quantar repeater will do it no problem, as will the GE counterpart, but as Aegis has no CTCSS tone it will not open a regular voice repeater.

Provoice is Aegis over EDACS and Opensky is Encrypted Aegis over EDACS, both require proprietary equipment.

I also have a fleet of GE M-PA radios capable of Aegis and encryption. I would like to be able to use them with a repeater, but a Quantar is out of reach for me. Right now I use them in simplex to protect from casual scanning.

If anyone knows what device we need to make a regular voice repeater handle Aegis I would be much appreciative.
N6DRA
Posts: 5
Joined: Sat Jun 16, 2007 10:03 pm

Re: MRK AEGIS with Conventional Repeater

Post by N6DRA »

I don't think you would have much luck running Aegis through a Quantar. The logic on the Quantar station control module wouldn't know what to do with an Aegis signal. The optimum solution would be to use a GE repeater (Mastr II/III) and a GETC (GE logic shelf). The GETC (with the right modem) would be able to demod and remod the digital signal as it should be and give decent range. Neither are overly expensive in this day and age.

Of course, by today's digital standards you would have a system that sounds like ass. Aegis isn't very good on it's best days, and is VERY range limited when used simplex. I have a few M-PA's that talk Aegis and a few M-RKs too but after using more recent equipment they appeal VERY little. Especially encrypted- that doesn't help with the older schemes!

BTW Provoice isn't Aegis over EDACS- that would be "Aegis over EDACS" (the current EDACS if you paid for digital)... Provoice is a totally different thing- a generation newer and much advanced over Aegis. Open Sky is IP routed networking and quite different from EDACS in the infrastructure and they way traffic is passed from site to site- it has nothing to do with encryption. Encryption is a totally different thing- other than doing things in certain ways to accommodate encryption, the repeaters and infrastructure couldn't care less.

Even with a Repeater/GETC there will be range penalties. The older digital just doesn't have the horsepower to provide the level of error correction for good range and fidelity. It would be a fun toy but don't replace an analog repeater and expect to get the same range from Aegis.

Good luck.

Tim
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