I am in the process of getting equipment together to put up a 220mhz repeater. I will be running Motorola CDM1550 mobiles, transmit radio will essentially be an exciter driving a continuous duty repeater amp. I will be interfacing the radios to a pi running asl3 for repeater control and linking capability. Kenwood has had a tri band handheld out for some time that does DSTAR on 220 and they are soon releasing a tri band DSTAR mobile. I am curious if it is possible to add DSTAR to this setup to have a mixed mode repeater. I am under the impression that DSTAR requires hardware to decode as the software decoders do not work well. I have a limited understanding of how this would be accomplished on any other analog repeater, but am unsure if it can be interfaced with allstar in some way.
DSTAR not so easy.
No direct usage/conversion with ASL.
You will need to use DVSwitch and some other hardware stuff if you want quality sound with a hardware vocoder. and patch that to asl.
(with usrp channel driver and analog bridge)
See the folks at dvswitch.groups.io
I know of a couple of repeaters that are analog (Allstarlink) and digital (MMDVM, DSTAR, DMR, YSF) but I don’t know how it’s being done. Obviously, they’ve got an MMDVM board interfaced directly through the repeater, and some way to switch between the Allstarlink controller and the MMDVM board, depending on what sort of signal is received, but that’s about where my understanding ends. I’m guessing they have two physical Raspberry Pi’s connected to the repeater, one for MMDVM, and the other running either HamVoIP or ASL. Don’t know which this system uses. It would theoretically be possible to run MMDVM_Host with an MMDVM board on the same rPi as ASL3, though it would require significant customization of the image.
It is certainly possible to use DVSwitch with an AMBE vocoder dongle (ThumbDV or DVMEGA DVstick 30) along-side ASL3 to translate DSTAR to analog and back, connecting to REF, XLX, XRF or DCS reflectors, then using normal FM radios to communicate to those reflectors, but I’m not sure if that’s what you want, or if you’re wanting the repeater to essentially be a native DSTAR/analog mixed-mode machine. These are quite different things.
I have quite a bit of experience making mixed mode repeaters but they’re not for converting analog and digital back and forth. That’s done in software, possibly off-site, and besides being pointless, always sounds terrible.
To make a repeater that does analog or digital as desired, simply split the discriminator (not line audio) to analog/Allstar and to the digital/MMDVM modem input. Connect PL&COS detect to Allstar’s COS in. Note there is no PL/DPL in digital, so digital will be ignored by Allstar (and analog will be ignored by digital).
Here’s where it gets tricky. Feed audio to the modulator (not mic in) through a DPDT relay, choosing one or the other. This prevents Allstar from munging up D-star, and D-star from ruining analog, should you happen to have both systems connected somewhere.
Use a Pi GPIO to operate the “traffic cop” relay. We can talk about scripts that automate the process. My approach would be NC comes from Allstar and NO comes from MMDVM/digital, common to the modulator. First device to assert PTT wins and holds the mode until done, then back to “scanning” for the next traffic.
Notice that since Allstar and MMDVM are duplex, the presence of a local user causes PTT to come back from the modem/interfaces, so the scan is halted whether or not it’s initiated from RF or the network.
It’s possible to have ASL and Pi-Star running inside the same Pi, but I prefer HamVOIP, so one would have to compile MMDVMHost into it. I’ve combined them both ways, but it’s cleaner and easier to have one Pi for analog and another for digital.
I have a video somewhere on YouTube from 2012 showing off this concept, with IRLP (analog) and MMDVMHost (digital) running both inside a Pi1!
Yes, vary easy. Use Dvswitch.
W2PW
It looks like this board could accomplish what you are talking about via hardware. Any thoughts?
I have done something like that with a couple of 1550’s. Using an STM board, I was able to to get D-star and DMR (one at a time). The 1550’s just repeat the digital coded signal letting the outside radios decode that properly.
I then used a ClearNode to bring D-star over to Allstar. Worked OK, until the CN lost it’s connection to the AMBE stick. You have to be real close to reestablish a connection back to the AMBE… not reliable!
I then got a dedicated Icom repeater to do D-star/Analog (one at a time, not joined).
Icom did a good job in hiding the signals needed to join it to Allstar!
@W8KAN - What specifically do you mean by a “mixed mode repeater”? If you mean a repeater that will respond to analog FM or a D-STAR transmission separately in a multi-mode setup than the MUX-25 you identified is one of the best “turnkey” ways to do it. The one downside to that (and any solution) is that there’s no hang time for a mode. You could have an analog transmission and then immediately have a D-STAR transmission right after it. Both will work, but the other mode can’t see the repeater did something outside of their mode.
If you mean a repeater that will pass audio to both analog and D-STAR at the same time, you’re talking about transcoding and no you cannot do that natively with ASL3 or with one single repeater. DVSwitch Server installed on ASL3 can transcode D-STAR into and out of analog/ASL3 but they aren’t simultanous modes nor can you send D-STAR commands via analog/ASL3 into the D-STAR system.
Yes, I think that board is for that very purpose.
I have an Icom repeater that has “mixed mode.” It repeats analog and it repeats D-star, but will not transcode between the different modes. On analog, you can hear the motor boating d-star signal being repeated.
You can convert a D-star signal and pass it to the repeater using allstar. You would need a Pi with Dvswitch and an AMBE stick… not real hard, but not that reliable…