OpenGD77

One simple way to compare radios is to just take the antenna off and "listen" to the termal noise. The meter should be in the -125dbm range iff it goes down to the -140 range it's probably not very accurate, +- couple of dbs

I get on 2m abaut -140 and on 70 cm abaut -124 to -128 dbm on fm, on Fmn abaut 3db better

oh2fhj wrote: ↑

Wed Feb 07, 2024 9:24 pm

Is there any easy way to calibrate the singnal meter ? I been trying to Google it, but haven't yet come across anything...

No. radio chip outputs a value between 0 and 255 and I had to manually work out a conversion between those values and dBm.

We had a Debug version which was able to display the raw values from the TRx chip, so that those values for a range of input signal levels could be plotted on a spreadsheet so that a appoximate line using offset and slope could be implemeted in the code

I'll need to build a Debug version of the MD2017 which displays those values

Does anyone know how to configure the official firmware for true Dual Watch

I've taken my radio apart and soldered wires to the MCU/CPU to try to understand how the 2 internal transceiver chips are controlled.

With the OpenGD77, I can now set each internal transceiver to different frequencies, but I'm having problems if both channels have signals on them, but this doesn't affect the official firmware

But what the official firmware does not seem to do is be able to be receiving on a secondary channel and the switch to the primary channel if a signal is received on that channel

If both channels have no signal then it switches to whichever channel has the signal, but at the moment it does not seem to switch if its currently receiving a signal on either the primary or secondary channel

VK3KYY wrote: ↑

Wed Feb 07, 2024 11:04 pm

No. radio chip outputs a value between 0 and 255 and I had to manually work out a conversion between those values and dBm.

We had a Debug version which was able to display the raw values from the TRx chip, so that those values for a range of input signal levels could be plotted on a spreadsheet so that a appoximate line using offset and slope could be implemeted in the code

I'll need to build a Debug version of the MD2017 which displays those values

Let me know if I can help in any way, I'm going traveling for a while soon, but if you build the code I can install it on my ht and take the measuring points if I only have time before I leave on the trip, otherwise it's going to be on a hold for two months or so

Too late today, but I can send you a special version tomorrow

Or perhaps Daniel can make a special version which displays the Raw values

We need a range of signal values to be sent to the radio and the Raw value recorded for each signal value

Tomorrow works for me too, noo pressure.

I made a quick video comparing 2m and 70cm sensitivity, and at least in my ear its the same. Off course the 70 cm has more loss in the sort cable run and and the meter was calibrated in 02 so there might be a fraction off a difference, also just by ear so it's not possible to tell exact db fraction like if you hock up audio feedback to the meter.

http://kride.dy.fi:83/mesurments/sensit ... d_70cm.mp4

VK3KYY wrote: ↑

Thu Feb 08, 2024 11:19 am

Too late today, but I can send you a special version tomorrow

Or perhaps Daniel can make a special version which displays the Raw values

We need a range of signal values to be sent to the radio and the Raw value recorded for each signal value

I have a Marconi 2022 generator, I can make some signal measurements on the RT-82 if needed.

For the record, I have a version that displays the raw values of the signal and noise.
Since I don't have write access to the storage site, please send me an email, I will send you a build of that version.
Roger will probably make it available widely in his next day.

Cheers.
---
Daniel

F1RMB wrote: ↑

Thu Feb 08, 2024 4:16 pm

For the record, I have a version that displays the raw values of the signal and noise.
Since I don't have write access to the storage site, please send me an email, I will send you a build of that version.
Roger will probably make it available widely in his next day.

Cheers.
---
Daniel

Where do I find your email?

On QRZ.com.