350qx range seems poor?? wants to come home at half a mile

[kevcov30]

Just wondering if any other 350 qx owners have had the same problem. Fly out to half a mile max and it goes into come home mode as the signal is lost. I was expecting a little more distance than this and wondered if this was all i should expect. Have pulled the rx aerial out through a hole i made in the bottom to try and improve things and put new batteries in the tx too. After buying some decent aerials for the fpv kit i now find i'm still limited in range. Any suggestions appreciated though i realise the 350 qx is a basic starter machine.cheers.Kev

[jamesb72]

I had range issues so have extended rx aerial using a bit of thin coax which made a big difference. Range test doubled and I can fly to limit of video range with no loss of control. I stuck pics on helifreak showing mod.

[kevcov30]

What sort of range were you getting before the mod? and how far have you taken it to now? I always thought the aerial length was related to the frequency.

[stevec]

The bit of the antenna that is critical is the bare piece at the end that is about an inch and a half long.  You can buy antennas from frsky for their receivers that you could solder on instead of trying to join one if you don't fancy doing that.

Cheers
Steve

[jamesb72]

Copy/pasted from the thread I posted on helifreak http://www.helifreak.com/showpost.php?p=5664552&postcount=1

Trimming the coax is very easy, just strip a bit of the end, then carefully measure 31.5mm and clip the inner wire at that exact length, only the tip is active (rest is shielded).

I've been really enjoying the 350QX with FPV, but flying further out have had range issues, today I did some thorough testing, and range with QX facing away (so aerial is closest) I am getting good RC range out to where my FPV video signal starts to break up, but when I turn nose in I lose RC much closer, around 2/3 my video range and less flying behind myself, this is very frustrating.

I bought some thin coax cable to make a remote aerial, stripping back using a sharp knife and measuring exactly 32mm then soldered this onto the QX board replacing the original aerial, this gives me an extended aerial so I can run this outside the body and attach to skid leg.

I just completed range tests to verify this, and looks pretty promising.

Std aerial gave me 11 paces range test nose in, 15 paces tail in.

Extended aerial just gave me 22 paces nose in, 30 paces tail in, so looks to have doubled the range based on range test.

http://youtu.be/xCH6sw9X1Ws

Video and pictures attached below show how this is done, the soldering is not as fiddly as I feared, if you have a thin tipped soldering iron and a steady hand this shouldn't be a problem.

I removed the top of body and undid the 4 screws holding the main board, so I could tilt it up to access underside, then desoldered the original aerial, and soldered the extended cable in its place using the red circled pad for ground/shielding.

I made a hole in the underside so I could loop the extended aerial straight down out of the body, then re-fitted the main board and put top back on.

I tested this in flight, I was getting OK range tail in but nose in would lose control about 2/3 distance, since the mod I have flown to the limit of my video with full control in all orientations, so this definitely sorted this for me.

I bought a short length of thin coax on ebay as part of an internal wifi aerial for Nintendo Dsi - it was 99p delivered, so was the cheapest thing on ebay I could find with a length of thin coax I could cut up.

[kevcov30]

Thanks James. Was looking for your post on helifreak but couldn't find it. Was wondering where to earth the shielding but your PIC was perfect. Will upgrade mine and see what I get. Looking forward to taking all those screws out the body again! Lol.