OpenGD77

OZ1MAX wrote: ↑

Sun Aug 13, 2023 8:26 am

GD77 in horspot mode MMDVM:
value 0 - 50mw
5 - 250mw
10- 500mw
15- 750mw
20- 1w
40- 2w
60- 3w
80- 4w
98- 5w

Hi.
I'm using a GD77 in hotspot mode too.
It's connected to a Pi3 using PiStar and works (mostly) fine.

The one thing not working is the adjustment of power levels.
The SW-102 shows the same rating (1W) when setting RFLevel=99 and RFLevel=1... .
Tested several other levels, it's 1W every time.

1W is fine for me, but I'd love to understand why the GD77 doesn't switch the levels.

Using the GD77 without hotspot mode the power levels can be switched WITH impact to the actual power delivered.

73, Christian, DO1BBQ

Does the screen displays the correct output power value ?

You can't really use such SW-102 to measure output power in DMR (because it's pulsed).

If you correcly entered the RFLevel value in the MMDVM.ini file, double check it, as it's up to MMDVMHost to send that value back to the hotspot.

different levels of TX power on the GD77(hotspot) should at least have some effect on the RSSI shown on my RD-5R using the hotspot.
It's always -81dBm no matter if it's RFLevel=1 of RFLevel=99.

The GD77 screen shows 5W with RFLevel=99 and 1W with RFLevel=20. Anything in between is shown on the GD77 like in the manuals table.
This part works fine.

73, Christian

That doesn't work like that.

You have to add attenuator on the RX, as you just saturate the rx chain being nearby. RSSI meter isn't a wattmeter (notice the 'I').

DO1BBQ wrote: ↑

Fri Dec 15, 2023 1:21 pm

different levels of TX power on the GD77(hotspot) should at least have some effect on the RSSI shown on my RD-5R using the hotspot.
It's always -81dBm no matter if it's RFLevel=1 of RFLevel=99.

The GD77 screen shows 5W with RFLevel=99 and 1W with RFLevel=20. Anything in between is shown on the GD77 like in the manuals table.
This part works fine.

73, Christian

Just trust the GD77 screen, if it says 5W it is the same 5W as if you use it as a normal radio.