VERY short telemetry radio range (less than 5 meters)

I think it’s ok now! Need to try it out tomorrow morning if there is no wind! I will keep you updated!

No luck… Same thing!!

I will go outside with my laptop running 3DR radio config tool where I can graph the four values:
image
And record the screen while moving my laptop or the drone!

The weird part of it is that it looses signal in 12 meters away from the drone, but when I’m close to it like 3 meters but behind a wall with the doors closed I still have reception. The noise is very strong no matter where I try!

@Dimitris_Stefanakis Now I tried to use a power bank to power the telemetry instead of the drone and now the issue doesn’t happen. Let me try to connect it back to the drone and test again

Okay, I tried basically everything I could! Change frequencies, net ID’s, channels…
This is what I observed!

  • The problem only happens when connected using mavlink, or trying to connect far away.
  • Tried to use a power bank to power the remote radio, the problem didn’t happen.
  • Tried to connect the power bank and drone at the same time, connected with mavlink, the issue happened again

Any thoughts on this? @Dimitris_Stefanakis @dkemxr @count74 @Allister
Btw sorry for ping guys, just trying to get this issue solved asap, or if not I will return them to banggood and buy from other seller or store.

Not really. Wrong antennas as mentioned maybe. You don’t have to post again about your indoor test, I read that. I probably have 10 sets of these radios and they just work. If you replace them just avoid the units that say 500mw, those are just noise makers. You could update them to V2 firmware I suppose but if the antennas are wrong or the units are just bad that won’t help. If the air radio doesn’t have a USB port you have to do it thru an FTDI adpater.

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It wasn’t an indoor test, but it only works inside as I said. It is V2 that has a USB port on both radios so I will try to upgrade

@dkemxr or @Dimitris_Stefanakis Please explain what is Duty Cycle in telemetry settings.
Because I keep finding things like this in the docs:

Some regions of the world allow for higher transmit power or more frequencies if you have a duty cycle below a given threshold. So for example in Europe you can transmit on a wider range of frequencies in the 433 band if your duty cycle is below 10%. Telemetry traffic is quite ‘bursty’, so the average transmit time is not generally high. When you set a duty cycle below 100% then your available bandwidth will be reduced, so you will find it will only work well for telemetry at higher air speeds.

What should I set it to? It’s now on 100, does it affect range?

That depends on where in the world you are. Each country/region has it’s own rules for radios.

https://ardupilot.org/plane/docs/common-telemetry-radio-regional-regulations.html#common-telemetry-radio-regional-regulations

My experience with these radios is they just work. Use the defaults. Unless you know the ins and outs of radio setup then don’t mess with it.

https://ardupilot.org/plane/docs/common-3dr-radio-advanced-configuration-and-technical-information.html

Or there’s also the chance that your knock-off cheap radios may not be cutting it. Maybe there’s a reason why the mRo units are twice the price as the Bangood ones? Did you fix the antennas with known good 433MHz antennas? Did you change your USB cable?

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I did change the USB cable a couple of times, but I don’t have any other antennas, so I don’t know how to test it

Dear @Yaros1,
Duty cycle is the time frame you transmission uses. i.e. 100 is 100%, so leave it as is for now.

Your tests don’t help much. The fact you connected with a power bank doesn’t mean anything for the quality of connection.

Please go outside at a fixed distance (let’s say 10m). With your drone and a GCS and grab a few minutes log. Then we can compare the onboard log and tlog for Mavlink related info and see whats wrong.

Iam out of lab for weekend, so I can’t check a pair of radios atm.

Oh! If you wish to get really deep in to it, Don’t forget to sent photos of your setup. Which telem port you use, Mav 1 or Mav 2, etc.

Best,
D

I connected the power bank to check if it’s something in my copter that’s interfering with the connection, but that’s not the case. Also I don’t understand why when I don’t connect to mavlink but just turn on both modules the range is much greater.

I will test it with the logs later today, but I think I will just return the radios and buy mRo radios. Because one of the radios randomly goes into bootloader mode (solid red), and other weird stuff like sometimes when I power them one of them blinks like it’s not linked but the other stays green like it’s linked, and it’s not connected to another one because when I power off the other one, it starts blinking green again…