OpenGD77

I will repeat my previous post. We are not currently able to support any more Alpha testers. Individually emailing each person takes time that is better spent on other things. The firmware has reached a stage where it is ready for Beta release which will be available to all. This needs additional wo...

I have found a bug in the power calculation for VHF which would account for some of the strange results. The correction should be in the next release from Roger. This should then make the 40W 25W 10W and 5W settings the same (or very similar) to the official firmware. Powers below 5W are not going t...

I think the level of noise probably depends on the resistance of the connections between the panel and the main board. Like Roger, my three radios only have a very slight, almost inaudible, sound in the background. Reseating the cable may well improve things on bad radios. Or maybe fitting an additi...

The eeprom and the flash are used for the codeplug, DMR database and voice prompts. They are used differently by OpenGD77 compared to the official firmware. Using OpenGD77 results in the eeprom and flash being changed. The official firmware may not work correctly if the eeprom and flash are not as i...

I am not sure what you are referring to regards the background? There is a very slight whine if you have the backlight set to less than 100% and this may be worse on some radios than others. it is due to interference between the backlight and the microphone supply. There is not much we can do about ...

Lorenzo,

Pins 7 and 8 of the microphone socket are connected to ground in the front panel. It might be possible to modify a radio and connect those two pins to the USB connections with a short twisted pair cable. I don't think anyone has ever tried to do it.

Colin.

Robert AA3RP..... The closest Log pot that I have been able to find is made by ALPS part number RK09L1140A5E . This is stocked in the UK by R.S Components and is also stocked by Mouser. It is listed as being discontinued on the Mouser site but they still have stock available at the moment. It fits t...

Thanks, that is a useful set of figures. As you can see, at the low power end the adjustment is very critical, especially on 2M. That is why it will most likely never be very accurate. I think you will find that is also changes with power supply voltage and temperature, so if you measure again in th...

I think those figure just show that the power calibration is a difficult subject. The gain of the PA stages varies significantly across the frequency range. The hardware does not have any way of measuring the output power, so the control is by an open loop with no feedback. It will never be very goo...

To AA3RP, Thanks for the offer of a radio for testing. Between the three main developers we already have examples of each of the 3 major radio versions. So at the moment we do not really need another. Hang on to it, there is a chance it may work with the new firmware when it is released. Colin G4EML.