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Using MMDVM to jury rig multi-mode digital transceiver

kb5udf

Member
Joined
Apr 7, 2004
Messages
523
Location
Louisiana
Hi all,

I was wondering if any one has successfully interfaced an MMDVM/pi combination type setup to an analog radio
to use for every day simplex and to talk to repeaters. I am not looking to build a repeater, mere to cobble
together my own multi-digital mode compatible radio as a hobby project. All of the internet material on the
subject I have seen has been about building a repeater. I just want an everyday transceiver, and I have a monoband
or two commercial uhf I could dedicate in the interest of experimentation (both a CDM and a Maxtrac, both of
which seem to work with MMDVM).

Any thoughts?
 

ergbert

Member
Joined
Feb 6, 2018
Messages
48
Location
FN22
I think what the OP is asking (correct me if I'm misunderstanding) is whether the MMDVM could be used to make an analog transciever into a multi-mode digital transciever, as opposed to creating a "megaspot", basically a hotspot using an analog transciever as the hotspot's RF section.

If it's the former, I'm very interested to hear more. I've already got the latter running.
 

kb5udf

Member
Joined
Apr 7, 2004
Messages
523
Location
Louisiana
Ah ok, got it, the mmdvm passes along that which has already been vocoded by other radios.

bummer...
 

ergbert

Member
Joined
Feb 6, 2018
Messages
48
Location
FN22
I think a MMDVM +vocoder board would be marketable. Way beyond any technical ability of mine, but I’d buy more than one. Turning an otherwise unused analog transceiver into one capable of several digital modes would be amazing.
 

KA1RBI

Member
Joined
Aug 15, 2008
Messages
485
. Turning an otherwise unused analog transceiver into one capable of several digital modes would be amazing.
OP25 has built-in software vocoders for d-star, ysf, and dmr as well as p25. I've used it along with an old 1980's Icom transmitter to, among other things, check into a weekly net on a local digital repeater. There are some differences in quality in d-star (d-star suffers from a lack of available documentation), and some operational issues (dmr mobile stations can't currently be done due to the difficulty of implementing TDMA) ..

passes along that which has already been vocoded by other radios.
There are other projects that offer decode (dsd for example), but to my knowledge only OP25 has transmit (encoding) built in...

Max
 

kb9mwr

Member
Joined
Apr 8, 2003
Messages
129
Location
Green Bay, WI
I think what the OP is asking (correct me if I'm misunderstanding) is whether the MMDVM could be used to make an analog transciever into a multi-mode digital transciever, as opposed to creating a "megaspot", basically a hotspot using an analog transciever as the hotspot's RF section.

If it's the former, I'm very interested to hear more. I've already got the latter running.

One of the first things Johnathan, G4KLX wrote was a D-Star client software. It would be nice if someone wold take this and add a few other modes. The other option is what Max mentioned, op25 has some primitive starts for client end use. Both require a knowledgeable person to further develop them. Anyone willing should raise their hand, so others can contribute to your beer fund :)

Digital_Voice-20130203.zip
tx\apps\gr-op25_repeater\op25 - op25 - Osmocom OP25
 
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