OpenGD77

Just wanted to check, re the calibration screens, per the manual they are not applicable to the MD9600. Assuming that is still current is there a method to perform calibration adjustments on the MD9600? I did do a forum topics seach for the word "calibration" but didn't get any hits.

Thanks for any advice/clarification.

Cheers - James.

ZL4JOCO wrote: ↑

Fri Sep 15, 2023 9:54 pm

Just wanted to check, re the calibration screens, per the manual they are not applicable to the MD9600. Assuming that is still current is there a method to perform calibration adjustments on the MD9600? I did do a forum topics seach for the word "calibration" but didn't get any hits.

Thanks for any advice/clarification.

Cheers - James.

Doesn't the version you are using have the calibration screen ?

Thanks for the quick reply. Yes I am running the very latest published firmware and it has the calibration screen. However I was refering to the manuual which says

Calibration screen

This screen currently only applies to the TYT MD-UV380 | Retevis RT-3S | Baofeng DM-1701 | Retevis RT-84.

See link: https://github.com/LibreDMR/OpenGD77_Us ... ion-screen


So I was unsure if the screens would actually do anything or worse do something bad on the MD9600.

Asking as the radio is expected to pull towards circa 18A at full power. On a 25W setting on FM VHF I am not even pulling 4A which seems odd.
I have a suspicion that the the power calibration data is out of whack based on the amperage draw I am seeing compared to the power setting selected which started me wondering about calibration data. It also Has me wondering if I can reload the saved calibration data from the radio from before firmware update from within OpenGD77/CPS.

Cheers - James.

The manual needs to be updated. Both the GD77 and MD9600 have had the calibration screen added a while ago.

Also, the UI for the calibration screen has now been standardised across all radios, with separate pages for each calibration area, i.e Power, VHF freq , and UHF freq


The power calibration is output power, not input current * voltage. Use a Watt meter.

Also, at the same time look at the current, because on some frequenceis these radios can't produce the advertised 40W and increasing the PA drive, in the calibration screen, just results in more current being drawn without any additional power

i.e if you keep turning up the power and the radio will only output 35W, then don't increase the drive any more, in fact, turn the drive down until you see a reduction in output power

These radios are sold as 50W but this is 50 Chinese Watts, and is only achieveable on VHF, some of my radios won't achieve 40W on UHF.

Re the screens - awesome. Thanks.

Re output power, will borrow/buy a meter to measure RF watts. I had been going on the probable max current draw derived from the fuses and what I had managed to find online.
Tests had been done in VHF.

Cheers -J

Never try to calibrate the Output power using the Input current.

Asking as the radio is expected to pull towards circa 18A at full power.

Also your calculations are wildy off for the amount of input current required

18A at 12V is 216W input, for 25W output ??

This would make the effeciency less than 15%

Max current is normally less than 8A for 40W

8A?! That's good to know and starts to feel right re what I am seeing. Mind you having 20A fuses seems odd. That along with what other similar radios delivering 40-50W were documented as pulling at max out is where I go expectations from. Maybe I read things wrong but that is where the ~15A came from. Not and special calcs.

But thank you for the help and guidance. This is all very new to me.

Cheers - James.

4A for 25W output seems about right.

Of that about 1A is used by the radio and driver stages. So let's say 3A is being used by the PA.

3A * 13.8V = 41.4 W DC input.

That's about 60% efficiency which sounds reasonable.

Colin G4EML

Isn't the frequency calibration on MD-9600 inside the radio?
Or can you do it via the software now?

SA0BUX wrote: ↑

Sat Sep 16, 2023 9:51 pm

Isn't the frequency calibration on MD-9600 inside the radio?
Or can you do it via the software now?

Software now.