EDACS system (or something else)?????

[Doogs38]

While I was scanning the 472-474MHz range today, I intercepted the odd voice comms that ended in a series of beeps; three (or four) beeps I think. Not the melodic tones of the firies or ambos, but simple short beeps about 1/2 sec apart. Is this what you would hear with an EDACs system, or is it something else? [I'm guessing that the is 470ish MHz freq range is too low for an EDACs system] Alex

[Phil]

Alex,
i know the noise you mean. some of the frequencies are listed to Vertel however you can run a trunking network on any band if you really wanted to

these is from the Vertel website
Teamtalk MPT
Teamtalk LTR
Teamtalk PMR

[Comint]

While I was scanning the 472-474MHz range today, I intercepted the odd voice comms that ended in a series of beeps; three (or four) beeps I think. Not the melodic tones of the firies or ambos, but simple short beeps about 1/2 sec apart. Is this what you would hear with an EDACs system, or is it something else? [I'm guessing that the is 470ish MHz freq range is too low for an EDACs system] Alex

The only KNOWN EDACS system in Queensland, is/was at Gladstone. And that system changed to a digital system about 12 months ago. Also, Vertel is not known to be operating EDACS systems.

However, and its a BIG however, in NSW and possibly Victoria, Vertel has been migrating some frequencies in the 450 to 500 MHz band, to NXDN. I don't know what NXDN sounds like, but it is a digital system.

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Comint

[Doogs38]

Thanks guys. I couldn't figure out what the beeps were and then read (in many places) that the beeps are typical of an EDACS system. I was aware from these forums that the only *known* EDACS system is/was at Gladstone...hence my question! I'm not suggesting that I have found a new EDACS system but I am very curious about those beeps; nothing else I've listened to in the western Brisbane area has them. The next time I have some scanning fun I'll record the exact freqs. Alex

[Comint]

Thanks guys. I couldn't figure out what the beeps were and then read (in many places) that the beeps are typical of an EDACS system. I was aware from these forums that the only *known* EDACS system is/was at Gladstone...hence my question! I'm not suggesting that I have found a new EDACS system but I am very curious about those beeps; nothing else I've listened to in the western Brisbane area has them. The next time I have some scanning fun I'll record the exact freqs. Alex

If it was EDACS, there would be a Control Channel to be heard.

And while the 'Official' Trunk Radio frequency bands in Australia are:-

165.1875 MHz + n * 0.0125 - where n is 1 to 240

415.5625 MHz + n * 0.0125 - where n is 1 to 200

864.9875 MHz + n * 0.025 - where n is 1 to 200

(source: Radiocommunications Assignment and Licencing Instruction: LM8 dated Dec 2000)

we all know that there are Trunked Radio Systems outside those areas, so it could still be EDACS (new, or previously unknown).

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Comint




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Comint

[Phil]

i have never heard a control channel off any of the vertel with the exception of MPT

[Doogs38]

Thanks guys. I couldn't figure out what the beeps were and then read (in many places) that the beeps are typical of an EDACS system. I was aware from these forums that the only *known* EDACS system is/was at Gladstone...hence my question! I'm not suggesting that I have found a new EDACS system but I am very curious about those beeps; nothing else I've listened to in the western Brisbane area has them. The next time I have some scanning fun I'll record the exact freqs. Alex

Thanks for the info above. I had another quick listen this afternoon and found the following freqs that had the 'beeps', and they're not all Vertel:
472.8000 - (Vertel) Chatter about pickups, addresses etc that made me think I was listening to a taxi service(?).
474.0000 - (Vertel)
474.2500 - I think this was one of the freqs.
474.5500 - Chatter about the 'airport' and 'black and white'; taxi service again?

I'll have to double check these freqs when I get the chance. Also listened to a rescue helo on 473.975 (Vertel)! Alex

[Phil]

472.8000 - Vertel
473.9750 - Vertel - Mt Coot-tha
474.0000 - Vertel
474.2500 - ComGroup - Mt Cotton
474.5500 - ComGroup - Mt Cotton

[Comint]

I had another quick listen this afternoon and found the following freqs that had the 'beeps', and they're not all Vertel:

You might be able to find some explanation of the 'beeps' here, if you haven't already looked.

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Comint

[Doogs38]

I had another quick listen this afternoon and found the following freqs that had the 'beeps', and they're not all Vertel:

You might be able to find some explanation of the 'beeps' here, if you haven't already looked.
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Comint

After doing a little research, it would appear that the beeps at the end of EDACS transmissions are there specifically to foil scanners. The EDACS 'anti-scanner' beeps keep the scanner's squelch open on a particular frequency while the real EDACS conversation switches to the next trunking freq. This foils the scanners ability to easily track an EDACS conversation.

I may well be wrong, however, I'm thinking that the beeps on the end of the Vertel (and other) system transmissions are there for a similar purpose: anti-scanner. How dare they do that! Alex

[Comint]

I may well be wrong, however, I'm thinking that the beeps on the end of the Vertel (and other) system transmissions are there for a similar purpose: anti-scanner. How dare they do that! Alex

It is amazing how when someone comes up with a stupid unbelievable idea about something, it just keeps on getting recycled.

The belief that the EDACS beeps were for anti-scanner purposes, has long being discredited.

With 99.999% percent of the electronics industry not even knowing that radio scanners exist, why would they waste valuable resources incorporating a feature which has no apparent use.

Worldwide, scanner users are of less significance than a single drop of water in the oceans of the world.

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Comint

[Doogs38]

It is amazing how when someone comes up with a stupid unbelievable idea about something, it just keeps on getting recycled.

The belief that the EDACS beeps were for anti-scanner purposes, has long being discredited.

With 99.999% percent of the electronics industry not even knowing that radio scanners exist, why would they waste valuable resources incorporating a feature which has no apparent use.

Worldwide, scanner users are of less significance than a single drop of water in the oceans of the world.

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Comint

Thanks for the feedback Comint - I guess you're telling me I'm wrong . Whatever the beeps are (end of tx notification?) they aren't a major distraction and I'm just curious.

I'm not sure I totally agree with your logic regarding scanner users being an insignificant minority. If we expand that minority group slightly to include all eavesdroppers; if we were really that insignificant then why would police et al need to use modulation/codification/encryption techniques to deny us the ability to understand what is being transmitted (or outlaw the ownership/use of scanners)? The obvious answer relates to the even smaller but socially significant 'criminal' minority who would use the information for ill gain, and a bunch of other reasons related to the transmission of sensitive information. And while the small 'criminal' element isn't representative of the vast majority of us honest folk who enjoy radio scanning, ultimately we're all tarred with the same brush and hence I don't think we're as insignificant as you suggest. Alex