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Connection lost with 3dr Radio

PostPosted: Mon Dec 02, 2013 8:09 pm
by Mlozano
Hello,

I have a 3dr Radio and it works well with distance <30m, but with distance >30m the QGC lost the connection.
In this image it shows the parameters.

https://www.dropbox.com/s/6ntr4vdq4d091 ... Config.bmp

Whats the problem? I expected 1 km of range

Thank you in advance,

Manuel

Re: Connection lost with 3dr Radio

PostPosted: Mon Dec 02, 2013 8:22 pm
by bluuu
check your antena, are you shure you have correct antena to bandwitch ? sometimes standard antennas isn't correct for 433MHz, check RSSI

Re: Connection lost with 3dr Radio

PostPosted: Mon Dec 02, 2013 8:47 pm
by Mlozano
I have this kit: http://www.eforchina.com/product/defaul ... ?id=120961
How can i check if I have the correct antenna?
Please see the images:
https://www.dropbox.com/sh/hrdnvuis0186zt0/lr5BLz-T9i

Thank you.

Manuel

Re: Connection lost with 3dr Radio

PostPosted: Mon Dec 02, 2013 10:59 pm
by bluuu
you have usb ver
As I remember this version has problems (usb converter interferences). But ... try to locate modem as far as you can on the copter, far away reciver and other stuff.
Check connection between PCB and antena connector.
Veryfing antena bandwich isn't easy ... but you can try other antennas
Another way ... try to lowering power.
Do you power up this modems without antennas ? It can burn amplifier on RFM module.

Re: Connection lost with 3dr Radio

PostPosted: Fri Dec 06, 2013 8:30 pm
by Mlozano
I have made some tests and I have seen that the RSSI signal level decreases a lot with the distance, and up to exact 5 meters the level is very low, only 130. With that distance between air and ground modem, if I move the air antenna close to the AQ board the signal level decreased to 110. The ground module always has a higher level of noise than the air module and never is lower than 50, and with the distance the ground module increase the noise more than the air module.
See the images (5 meters, 0.5 meters) : https://www.dropbox.com/sh/1sju8w2g0qr1ez0/hYu7qihwv1

I think that I have never turned on the modems without antennas.

I'm going to replace these antennas and if the problem doesn't dessapear, i will buy another air radio to avoid the interferences. I don't see another way.

Could anybody help me about which kind of 433 mhz antennas are good?

Re: Connection lost with 3dr Radio

PostPosted: Fri Dec 06, 2013 9:37 pm
by skew
Mlozano, Take a ohm meter and see if there is a short between the center conductor and outside ground there should be none if there is thats your problem something is shorting your antenna. I had one radio that there was a little piece of metal on the back of the 3dr that was stuck between the two from manufacture causing no range for me.

Re: Connection lost with 3dr Radio

PostPosted: Fri Dec 06, 2013 10:49 pm
by Mlozano
Hi Skew, I have checked that there isn't a short between the center conductor and the Shielding.

Re: Connection lost with 3dr Radio

PostPosted: Sat Dec 07, 2013 7:19 am
by joebar.rc
It has been reported several times, for example look at http://diydrones.com/forum/topics/range ... 3mhz-radio

Somebody made an X-ray picture from the 433 antennas, it are actually 2.4Ghz antennas. A recommendation for better antenna sources is also there. On the RGC there is a thread too. You probably have also that batch with wrong antennas

Menno

Re: Connection lost with 3dr Radio

PostPosted: Fri Dec 13, 2013 9:35 am
by Mlozano
I have bought two 433Mhz antennas and the problem is not resolved. The RSSI signal haven't changed, is the same than with the older antennas. I will order a new air module for avoid the interfereces. Maybe its a good idea change the information of the Aq Wiki....

Re: Connection lost with 3dr Radio

PostPosted: Fri Dec 13, 2013 12:27 pm
by skew
Something has to be wrong with one of your radios hopefully a new one will fix you up. I have done multiple missions 3/4 mile out and 400ft alt with no loss of connection on my rctimer 3dr 900mhz radios stock antennas. My settings are the same settings as you are using. Your 433mhz should have more range than my 900mhz if they are working correctly.