GD-88, the new Radioddity DMR radio

ve2ugo
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Location: Quebec, Canada

Re: GD-88, the new Radioddity DMR radio

Post by ve2ugo » Thu Aug 11, 2022 6:44 am

W5RAH wrote:
Wed Jul 20, 2022 6:03 am
It looks to be along the same lines as the Kydera DM880UV. Their DB-25G mobile is also derived for the similar Kydera product. I have one of the DB-25G radios and it seems to work fine as long as you use the third party CPS.
Exactly, the Kydera is a true dual band. It can receive DMR or FM at the same time on each side and has independent digital volume control.
They even make an LTE/WiFi version of the same model.
But the DB-25G is not a true dual-band.

I would also like the return of real dual bands with 2 physical volume controls, each with its own Squelch.
ve7mdt wrote:
Mon Aug 08, 2022 7:21 am
Of course I meant cross band repeat that works with DMR mode at least on one side. My first dual band radio was the Standard C550 (Asian version of the C558A, which I also acquired lately as a spare as the old one was getting bad) and it has cross band repeat. I bought it in 1993. It was not that uncommon back then, as a matter of fact, almost all dual band HT models during that era all could do cross band repeat. My other models that I have owned and still owned today, have these: Alinco DJ-580T (owned 2 i diff time frames), Icom IC-24AT (had been having problems), Yaesu FT-51R. I have also owned Yaesu FT-470, iirc, also has that feature.

The Standard C558A was really a good radio for its time.

Cross-band repeat was also interesting in the 1990s. And you could often just plug in a simple 12v power cord to operate and charge the radio. No need for Battery Eliminator and another charger...

It would be interesting if the GD-77 could serve as an interface to connect to the Raspberry Pi for communicate digitally via the Internet on various networks. It couldn't do it in RF given the architecture but could do it otherwise.
A bit like the Node-Ventures and the interface they created that will connect to the Raspberry with a speaker and microphone that will allow you to talk on various digital modes via the internet. We replace the module and take the GD-77.
The tools are already there with among others MMDVM_Bridge and Analog_Bridge from DVswitch.
It would just be necessary for the GD-77 to be able to talk to the computer and the radio could surely do even more without having to make heavy physical modifications.
An idea like that in order to make it evolve even more since it is itself limited, it will then need external tools to do even more in a radical way.

73!
Last edited by ve2ugo on Thu Aug 18, 2022 5:46 am, edited 1 time in total.

VK3KYY
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Re: GD-88, the new Radioddity DMR radio

Post by VK3KYY » Thu Aug 11, 2022 7:35 am

ve2ugo wrote:
Thu Aug 11, 2022 6:44 am
....

It would just be necessary for the GD-77 to be able to talk to the computer and the radio could surely do even more without having to make heavy physical modifications.

There are no analogue audio paths to the CPU in the GD-77, so it would not be possible to do what you discussed without significantly modifying the hardware.

ve2ugo
Posts: 46
Joined: Sat Nov 16, 2019 5:28 pm
Location: Quebec, Canada

Re: GD-88, the new Radioddity DMR radio

Post by ve2ugo » Thu Aug 11, 2022 8:21 am

Would it be possible to do then like a Node-Ventures but with just the DMR function in RX/TX but allowing multimode via the raspberry pi. It could thus in HotSpot mode have access to AllStar, Echolink, YSF, D-Star, NXDN and P25. The only thing is that the input and output will absolutely have to be DMR.

VK3KYY
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Re: GD-88, the new Radioddity DMR radio

Post by VK3KYY » Thu Aug 11, 2022 11:28 am

ve2ugo wrote:
Thu Aug 11, 2022 8:21 am
Would it be possible to do then like a Node-Ventures but with just the DMR function in RX/TX but allowing multimode via the raspberry pi. It could thus in HotSpot mode have access to AllStar, Echolink, YSF, D-Star, NXDN and P25. The only thing is that the input and output will absolutely have to be DMR.
The radio won't support any other digital modes than DMR because its call controlled via a dedicated DMR only chip.

FM is onl via direct paths from the mic to the RF chip and from the RF chip to the speaker

For DMR Tx the DMR chip directly modulates the master reference oscillator, all the RF chip does is produce what it thinks is a silent carrier, because its mic input is turned off.
For DMR Rx, the audio from the RF chip is routed directly into the DMR chip which does the complete decode into the high level DMR data, i.e the Source and Destination ID's and the audio byes etc.

There is no low level access to the decoded 4FSK inside the DMR chip and no way to tell it to modulate a 4FSK bitstream.

ve2ugo
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Location: Quebec, Canada

Re: GD-88, the new Radioddity DMR radio

Post by ve2ugo » Thu Aug 11, 2022 11:51 am

In HotSpot mode, the gd77 receives a dmr signal which sends it to the raspberry pi which is processed via a software suite, including mmdvm. This one does the routing or transcoding according to the command sent at the Pi-star for example. If I dial TG 71083 I communicate in YSF but i'm in dmr. The radio sends and receives in dmr only but transcoded in the desired mode via the raspberry pi. The flux will always remain dmr for the gd77.
By adding some modules, it is possible to add options like dstar, allstar and echolink. The mmdvm and other tools will do the dmr to ysf, dmr to p25, dmr to d-star but passing via internet and not rf.
The mmdvm and dvswitch will simply hook up and transcode the dmr stream to the desired mode.

It will not be possible to use any other radio with the hotspot than a dmr radio. It's clear. But transcoding the dmr in another mode via Internet surely...

The processing has nothing to do with the radio's internal chip. Everything could be done externally and sent in dmr to the radio. It would be a way to cheat to gain access to other modes and networks.

ve2ugo
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Location: Quebec, Canada

Re: GD-88, the new Radioddity DMR radio

Post by ve2ugo » Thu Aug 18, 2022 5:30 am

ve7mdt wrote:
Wed Aug 17, 2022 9:48 am
(...) Moreover, what's being asked above is about development on both the radio side but also the "hotspot" side, which has never been the focus of this development and this forum. I suggest my fellow Canadian ham to seek that level of commitment from the hotspot platform people instead.

And I thought this thread is about the new Radioddity GD-88? Please don't hijack the thread, thanks!
David VE7MDT,
OpenGD-77 has a Hotspot feature that is already part of the project as well as other features that other developers found personally interesting.
The firmware has a hotspot function and the forum has a topic to discuss it. If you judge this negatively, it is your choice but do not decide for the others which functions are at the center or not of the development or which are more relevant than others. Many have repurposed the GD-77 as a Hotspot and mostly like this feature.
It is obvious that if the GD-77 allows to go on D-Star, AllStar link or echolink, to name only those, that the community would greatly appreciate.
The proposal discusses, among other things, the HotSpot function already present since it uses the same connection with the same Raspberry Pi and some identical applications in order to extend the functions of the GD-77 even more.
Firmware suitable for Raspberry applications could extend functions and capabilities to several levels. But you probably already understood that.
Improving the functions of the GD-77 had never been approached from this angle. Why decrease that?
Sincerely sorry for having taken the trouble to answer Roger as best I could, in my second language, in order to make myself understood. Now, Roger and I know that the principle (idea) is possible but that it takes the investment of someone who has the time since it is currently not a priority for him.

You will notice that in this subject the majority of your interventions concern other radios than the GD-88 or even digital radios. :lol: ;)

Thank you for your understanding and respect! Let's stay constructive and positive!


--------------------------------------------------------------------------------------------------


The topic regarding: ''Proposal GD77 Multimode + Web Transceiver'' will continue here: https://opengd77.com/viewtopic.php?f=7&t=2348 in order to respect the initial subject which, inadvertently, branched off to the subject of the development of the GD77 which had not yet been approached from this angle and which is still THE subject of the forum.

Sorry for wanting to clarify this great opportunity in this topic to make sure we all understand each other and thank you for your understanding! Let's stay positive and good development! We will continue elsewhere.


-- Let's continue on the GD-88 or kydera dr-880uv which is the same radio. --


73!

VK3KYY
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Re: GD-88, the new Radioddity DMR radio

Post by VK3KYY » Fri Aug 19, 2022 5:59 am

This thread has been moved to the Off Topic section because of complains from multiple forum members that this is an off topic post and show therefore not be in General Discussions relating to the GD77

This forum is only to help people support each other in the use of the firmware, and for the developers to announce when there are updates to the firmware.

Mostly everything else is off topic, but we do also try to help people who are new to DMR understand how to use their hotspot as well as how to use the firmware.

AA3RP
Posts: 97
Joined: Thu Jun 17, 2021 3:22 am

Re: GD-88, the new Radioddity DMR radio

Post by AA3RP » Sat Aug 20, 2022 6:07 pm

Does anyone know what hardware the GD-88 is based on?

What CPU(s) / DMR / VFO / etc. and if it single or dual rx / tx hardware?

AA3RP

ok1pt
Posts: 167
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Re: GD-88, the new Radioddity DMR radio

Post by ok1pt » Sun Aug 21, 2022 3:40 am

AA3RP wrote:
Sat Aug 20, 2022 6:07 pm
Does anyone know what hardware the GD-88 is based on?

What CPU(s) / DMR / VFO / etc. and if it single or dual rx / tx hardware?

AA3RP
Hi!
I don't know anything about internal details, it's not stated anywhere, but I've got the radio this week, and I can confirm, that it's really dual RX. About the CPU, I have only one trace - the programming cable contains Prolific PL-2303 USB to serial converter, so the CPU is probably different from those we can use for running OpenGD77.

With regards & 73
Pavel OK1PT

DO3HB
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Joined: Tue May 25, 2021 4:38 pm

Re: GD-88, the new Radioddity DMR radio

Post by DO3HB » Sun Aug 21, 2022 8:26 am

AA3RP wrote:
Sat Aug 20, 2022 6:07 pm
Does anyone know what hardware the GD-88 is based on?

What CPU(s) / DMR / VFO / etc. and if it single or dual rx / tx hardware?

AA3RP
Here you can look inside this radio:

https://fccid.io/VO6DR-880UV/Internal-P ... 958935.pdf

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