Hi,

I recently bought two Meteor 75 Pro. One with FrSky and the other one with ELRS. The one with ELRS has a very weak video signal. After I observed this behaviour I tested the output signal strength with the ImmersionRC RF power meter and it is very low and does not change when I set 25, 100, 200 or 400mW via the OSD. The color of the LED on the VTX is changing but the output power measured at the antenna stays the same. 

My other Meteor 75 Pro with FrSky behaves normal and has much higher signals at the antenna. The measured output levels change in correspondence to my settings. In Betaflight both drones look almost identical besides that the ELRS drone shows in the VTX sheet that it uses Smart Audio 2.0 and the FrSky drone shows just Smart Audio.

Both drones seem to have a new VTX M03 hardware version (v1.2?), as you can see on the attached picture. 

Has anyone an idea why the output power is so low?

Thanks for your help!

(15-Apr-2024, 02:41 PM)quadbee Wrote: Hi,

I recently bought two Meteor 75 Pro. One with FrSky and the other one with ELRS. The one with ELRS has a very weak video signal. After I observed this behaviour I tested the output signal strength with the ImmersionRC RF power meter and it is very low and does not change when I set 25, 100, 200 or 400mW via the OSD. The color of the LED on the VTX is changing but the output power measured at the antenna stays the same. 

My other Meteor 75 Pro with FrSky behaves normal and has much higher signals at the antenna. The measured output levels change in correspondence to my settings. In Betaflight both drones look almost identical besides that the ELRS drone shows in the VTX sheet that it uses Smart Audio 2.0 and the FrSky drone shows just Smart Audio.

Both drones seem to have a new VTX M03 hardware version (v1.2?), as you can see on the attached picture. 

Has anyone an idea why the output power is so low?

Thanks for your help!

Is your VTX locked? What does your VTX table look like? Maybe the VTX is stuck on 25 mW.

However if the color on the VTX is changing you have have a hardware issue. Is the antenna connector on the VTX ok?

I have the same VTX on my Meteor65 but I only fly in the house and I have not checked the actual output. It does change from 25mW to 100 mW on the OSD when I arm though.

There are differences between different versions of Smart Audio.

https://intofpv.com/t-what-smartaudio-version-do-i-have

https://oscarliang.com/smartaudio-tramp-...vtxtables/

Thanks, but I´ve found the reason. 

The amplifier IC (PA5542) on the VTX is physically damaged, as you can see on the attached picture. There is a hole in the upper shell of the IC.  I have never seen something like this before and have definitely not hard landed this drone. After swapping the VTX against a new one, everything runs fine. It took me 2 days of research and a sleepless night to figure it out.

(15-Apr-2024, 08:31 PM)quadbee Wrote: Thanks, but I´ve found the reason. 

The amplifier IC (PA5542) on the VTX is physically damaged, as you can see on the attached picture. There is a hole in the upper shell of the IC.  I have never seen something like this before and have definitely not hard landed this drone. After swapping the VTX against a new one, everything runs fine. It took me 2 days of research and a sleepless night to figure it out.

Yikes!!!! That's definitely a hardware issue.

Could it have been left in a higher power setting for too long ( maybe when setting up, or after a crash before getting too it) without airflow and it overheated and popped it?

(15-Apr-2024, 09:27 PM)Timmyhawk 2 Wrote: Could it have been left in a higher power setting for too long ( maybe when setting up, or after a crash before getting too it) without airflow and it overheated and popped it?

If it was due to that, it's basically the reason i use the "low power on disarm" setting.  If you disarm it goes back to 25mW.

But could be an issue with the newer one. My old M03 works fine without a fan. Had it without a fan for a good 10 mins before I realised.

(15-Apr-2024, 08:31 PM)quadbee Wrote: Thanks, but I´ve found the reason. 

The amplifier IC (PA5542) on the VTX is physically damaged, as you can see on the attached picture. There is a hole in the upper shell of the IC.  I have never seen something like this before and have definitely not hard landed this drone. After swapping the VTX against a new one, everything runs fine. It took me 2 days of research and a sleepless night to figure it out.

Your excellent photo has solved that mystery!  That IC was improperly "placed" between the PCB traces (off-center towards the bottom) by half a pad. If you are a bench guy, you could order a 5542 and replace it. (Nice to have a spare, or put it on another whoop!)