MD9600 Remote Head.

G4EML
Posts: 942
Joined: Sat Nov 16, 2019 10:01 am

Re: MD9600 Remote Head.

Post by G4EML » Tue Sep 12, 2023 10:37 pm

It sounds like you probably have the latest version already.

I did consider adding an amplifier at the head end but didn't try it as I prefer to use the mic connected to the radio.

Colin.

ZL2FL
Posts: 29
Joined: Mon Sep 14, 2020 6:26 am

Re: MD9600 Remote Head.

Post by ZL2FL » Tue Sep 19, 2023 3:00 am

Righto gents, my first attempt to get this working has unfortunately failed. Symptoms are just a blank screen and no controls working. Not sure if there is supposed to be a heartbeat led on the Pico? The radio started up with the normal morse code jingle. Mic buttons appear to do things plugged into the radio, but hard to know with no display.

I've checked all the soldering, especially for the ribbon connectors and that all looks clean and solid. Cat 6A cable of around 3m used for the first test.

Any pointers on fault finding will be much appreciated.

Latest firmware installed and works fine with the standard radio, not sure if there is a setting in the menus I should be looking for?

Colin
ZL2FL

VK3KYY
Posts: 7622
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: MD9600 Remote Head.

Post by VK3KYY » Tue Sep 19, 2023 3:05 am

ZL2FL wrote:
Tue Sep 19, 2023 3:00 am
...
Latest firmware installed and works fine with the standard radio, not sure if there is a setting in the menus I should be looking for?
...
No special settings needed.

I think Colin G4EML will need to answer with some suggestions

ZL2FL
Posts: 29
Joined: Mon Sep 14, 2020 6:26 am

Re: MD9600 Remote Head.

Post by ZL2FL » Tue Sep 19, 2023 3:08 am

I figured it was probably his wheelhouse :)

First bit of debug - powering up the pico with usb power does give me the "MD9600 remote head" message - good start! Which i guess means I should look at power supply to the head first.

ZL2FL
Posts: 29
Joined: Mon Sep 14, 2020 6:26 am

Re: MD9600 Remote Head.

Post by ZL2FL » Tue Sep 19, 2023 3:36 am

Working!

Not 100% sure what the issue was, I re-seated the ribbon cables and tried a new extension cable and we were away. Went back to the first extension cable and that's fine too. So I'm guessing one of the ribbon cables was the issue.

On first use it does have a couple of quirks around processor noise with FM squelch open and the volume control is kind of 'stepping'. I'll use it for a while and see how it sounds in use on digital.

Thanks guys for the work you've done to get this up and running.

Colin ZL2FL

G4EML
Posts: 942
Joined: Sat Nov 16, 2019 10:01 am

Re: MD9600 Remote Head.

Post by G4EML » Tue Sep 19, 2023 11:46 am

Glad to hear you managed to get it working.
I am not sure why it didn't work first time. The raspberry pi pico in the head has to 'remember' the power on/off state, and this has to be in sync with the state of the main processor. It could be that takes a few power cycles to get correct.

The MCP4023 volume control chip only has 64 possible settings, so the volume control will move in steps. If you normally use the radio in a quiet environment you could change the zero ohm resistor on the radio board to a larger value which would reduce the maximum volume and spread the 64 steps over the lower range.

Noise pickup is down to the way TYT designed the front panel, the ground connection is shared by the audio and the display. Fitting the volume control chip at the radio end of the cable reduced the noise pickup. However the ground is still common through the short ribbon cable to the radio. On my radio the noise is barely noticeable but that may vary between radios. The ribbon cable has some resistance so it might be worth adding a short extra wire directly from the radios ground to the ground of the new PCB.

Colin.

ZL2FL
Posts: 29
Joined: Mon Sep 14, 2020 6:26 am

Re: MD9600 Remote Head.

Post by ZL2FL » Tue Sep 19, 2023 7:42 pm

Thanks for the info Colin

Yes, unfortunately the background processor noise on receive on my radio is very high, to the point of annoying on DMR. I'll experiment a little with earthing as you suggest and see if I can improve it any. I've also found the maximum volume to be somewhat lower with the remote head - but I've also done the mod to tame the rather sensitive volume control on the standard radio so that may have some impact as well.

I think as you suggest it did take a couple of cycles to sync the radio and remote, although the initial problem must have been no power as I would have expected the the MD9600 remote head message even if nothing else worked?

Colin
ZL2FL

pu4aap
Posts: 2
Joined: Sun Mar 03, 2024 7:25 pm

Re: MD9600 Remote Head.

Post by pu4aap » Tue May 21, 2024 10:58 pm

Hello goodnight!
How do I get the program modified from openGD77 to the MD9600? I didn't find it in the archives.

G4EML
Posts: 942
Joined: Sat Nov 16, 2019 10:01 am

Re: MD9600 Remote Head.

Post by G4EML » Tue May 21, 2024 11:05 pm

No special firmware is required.
Remote head support is included in the standard firmware.

pu4aap
Posts: 2
Joined: Sun Mar 03, 2024 7:25 pm

Re: MD9600 Remote Head.

Post by pu4aap » Thu May 23, 2024 3:57 pm

Thank you very much!! Strong 73!!

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