As analog VHF/UHF are close to needing the last rights in my area I have a few questions about Digital voice on VHF/UHF. Is there much simplex traffic ? Are the The repeaters stand alone or are they all connected via the internet ? ( not my thing) Is there a way I can decode Digital voice signals just to give me an idea of the amount of traffic on VHF/UHF in my area ?
Thanks all
Brad
I’d be very surprised if digital voice (non repeater or gateway) was more active than fm. You need to see what repeaters or gateways are active in your area and which modes they support. Are there any local clubs that can advise you?
Dunno about whether you can programme a pc to decode any of the major digital modes - it’s well beyond my IT skills
I’ll be honest and admit I haven’t a clue about the Digital voice modes, I’ve been away from radio for 16 years or so. The VHF and UHF bands are pretty dead in my area and although calling CQ on local repeaters during my daily commute I only seem to get an answer once every two weeks or so. There is only very rarely anyone on and from what I hear it’s as if they have messaged each other before hand. I’m toying with the idea of removing the radio as the car gets left in remote areas when I am out walking with my dogs and this would remove the small risk of someone breaking in to take it. I have tried to listen on local digital repeaters ( on an analog radio) just to see if I hear anything and generally I hear nothing. I wondered if there were any decoding programs for the various modes just to see if I heard anything before spending more money. I’m starting to find radio frustrating rather than a pleasure due to the lack of activity. I have been told by a work friend that here are some nets in my area on AM/SSB CB radio on the legal bands so I may dig out the reciever and string up an antenna to see if I hear anything there !
Hi Brad,
A couple of points, that are often forgotten.
Digital voice (DStar, DMR, YSF etc.) are actually FM transmitters where the audio being sent on them has been digitised.
DV modes can work in Simplex mode and in this mode normally give better audio quality than standard Narrow FM, but can have a shorter range (because of the cliff effect).
The majority of DV conversations happen within Internet-based teleconferencing “rooms”. These are set up based on location or a particular purpose - e.g. one might be for ham radio operators who are also train spotters.
These rooms are accessible via repeaters but the majority of these room users have a DV hotspot in their home or car and transmit from a HT into these “super-mini-access-points” and on over wifi or cell data service into the Internet and to the VOIP discussion rooms.
So your chances of finding a DV transmission “in the wild” will depend upon your location.
Apart from M17, which uses the Codec2 open source transcoder, the other DV modes use a proprietry CODEC for which a licence has to be paid.
A few expensive scanner receivers may have support to decode the signals but your best option will to try to find which of the 4 main standards are in use where you are and buy a HT with scanning capability to listen for the contacts.
If you are lucky enough to have DMR activity in your area, those HTs are generally the cheapest.
There are also Smartphone Apps that allow you to listen into and in some cases join the “rooms” but that is all activity directly within the Internet and not what you are looking for.
Well, that turned out to be a longer explanation than I expected but I hope it answers your questions.
73 Ed DD5LP.
Remember the golden unwritten rule. Always give 2m and 70cm a quick tickle when activating or just out and about /M /P /MM (/AM?). It should be a license-revokable offence if folks don’t!
Or, just go to any web vhf/uhf rx that covers your area. They usually have digital voice option
Virtually nothing around here. Like Ed says, there’s no reason why you can’t do simplex DV.
I’ve had 1 ad hoc DStar contact from a GW/NW summit over to GD, calling CQ for a few minutes on 144.6125 MHz, their first simplex DV contact.
I’ve had a few other contacts on C4FM fusion from summits, but only after spotting myself or if I’m chasing someone else who has spotted.
The local DV repeaters fire up often (I think they’re all Fusion) but they all seem to be connected to Hubnet.
Thank you Ed for your explanation, I now know a hell of a lots more ( which was nothing) than I did before.
The only time I have heard anybody using DV simplex has been for SOTA activations, nobody really uses DV repeaters, especially the ones that churn out Freestar