OpenGD77 - Repeater

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G0FHM
Posts: 17
Joined: Mon May 14, 2018 8:47 pm

Re: OpenGD77 - Repeater

Post by G0FHM » Mon Oct 14, 2019 12:58 pm

Hi Andrew,

Pistar supports the GD-77 as a hotspot (Programming cable from radio to USB on the Pi), with the OpenGD77 firmware.

I have both GD-77's plugged in at the moment, and one is a mirror of the other one currently, so they aren't linked to avoid looping and disrupting any network.

If any member of the dev team wants to SSH in and have a poke around to see what is what, then PM me and i'll give you the IP.

Thanks,

J

PS, I do have a dual board here that I can hook a couple of mobile radios to, but i'm on a tight budget, and would rather not have to shell out on a pair of Motorola radios, which tend to hold their value fairly well! GB7GS is now in the vetting system, and it's going to be a low power repeater (10w ERP) to boost the eastern flank of GB7PE (When it comes back) and to give DMR to the Fens while PE is off. I can achieve the ERP by 1w out, so hopefully things won't get too hot. I have had 1x GD-77 running 1w into a dummy load for a while now, linked to BM & DMR+ simultaneously (so it is rarely quiet), and thermal stability seems to be ok.

ct1dvm
Posts: 163
Joined: Thu Apr 19, 2018 6:34 am

Re: OpenGD77 - Repeater

Post by ct1dvm » Wed Nov 06, 2019 11:54 pm

G0FHM wrote:
Sat Oct 12, 2019 11:30 am
Hi Andrew,

Thanks for a sensible response!

I have a second GD-77 on it's way. I think it could be a popular addition, as you would have a 5w quite easily portable repeater, ideal for RAYNET or other such EMCOMM groups. The downside could potentially be that anybody could start popping up with unlicensed repeaters.....

When I get the second GD-77, I can always plug it in to the Pi, and if a member of the dev team wants too SSH in and have a snoop around (if it will help), then by all means, feel free.

I have an application for GB7GS (70cm DMR) in the vetting system at the moment, and it would be nice if it could be the first OpenGD77 repeater, rather than doing it the "traditional" way.

Cheers,

James
Yes a 2nd mmdfvmhost instance can be added to pistar on custom frequency shift. Using common network connection with different return port, which would act as a repeater. 10 Mhz shit recommended. Radios would need to be TX and RX locked in programming ?

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kd2lh
Posts: 13
Joined: Thu Aug 22, 2019 3:26 pm

Re: OpenGD77 - Repeater

Post by kd2lh » Mon Nov 11, 2019 2:40 pm

Roger Clark has been making steady progress on his OpenGD77 firmware for the Radiooddity GD-77 HT. It is now in beta testing, and is supporting tier 2 DMR. It's in limited Beta distribution while the code is stabilized:

http://rogerclark.net/opengd77-hotspot-mode/

To be clear, this solution uses the GD-77's radio hardware and runs his ported version of MMDVM within the radio itself.

When the GD-77 is plugged into the Raspberry Pi using the USB cable (same as used for CPS programming) Roger's community firmware switches into HotSpot mode (it's simplex only). He currently configures Pi-Star as using one of the "Zumspot" family of hotspots (he specifically used "Zumspot Libre USB" for configuring the Modem type in Pi-Star.

I'd like to see "Open GD77" added to the modem types table available in PiStar with the device description "Open GD77 HotSpot" as the description that is displayed in Pi-Star's dashboard and admin left sidebar.

This solution completely replaces the SDR radio components in boards like the JumboSpot "HsHat" with a 5 watt transmitter and radio receiver running MMDVM firmware within the GD-77 HT radio. It's pretty slick, and I expect we'll see this become a viable and even preferred choice for event hot spots as Roger's firmware reaches maturity.

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kd2lh
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Joined: Thu Aug 22, 2019 3:26 pm

Re: OpenGD77 - Repeater

Post by kd2lh » Tue Nov 12, 2019 2:46 am

I just checked R4.1.0 RC6 with the latest updates, and OpenGD77 is listed as a modem option. Thanks!

G0FHM
Posts: 17
Joined: Mon May 14, 2018 8:47 pm

Re: OpenGD77 - Repeater

Post by G0FHM » Tue Nov 12, 2019 7:29 am

Yes, i've been using it for quite a while now!

IZ4FXT
Posts: 9
Joined: Tue Jun 19, 2018 11:11 am

Re: OpenGD77 - Repeater

Post by IZ4FXT » Fri Nov 15, 2019 11:16 pm

I'm very interested also, in the possibility of connecting two gd77's acting them as a standard not-too-low power repeater!
Coming from two HS Dual Hats, very bad in receiving (yes, worse than the 20mW on TX!!!).

I just leaved a comment in Roger Clark blog asking for that, He and his friends are making some good steps in tier2 mode that is necessary for the repeater mode.
I think pistar also has to be part of the work, having to split the rx side to another usb than tx side, so I'm writng also here.
Thank You in advance
Stefano IZ4FXT

BTW: still nothing about an "openMD380" firmware with hotspot (repeater?) mode?

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