FrSky XHT diy 2.4 ghz RF module

Like B&Q for homebrew radios
Martin
Posts: 539
Joined: 16 Feb 2018, 14:11
Location: Warwickshire

Re: FrSky XHT diy 2.4 ghz RF module

Post by Martin »

Here's my reply from the other thread: viewtopic.php?f=62&t=1054&p=10216#p10216
JohnRogers
Posts: 14
Joined: 09 Dec 2020, 10:42

Re: FrSky XHT diy 2.4 ghz RF module

Post by JohnRogers »

Thank you all for your response and help

John
JohnRogers
Posts: 14
Joined: 09 Dec 2020, 10:42

Re: FrSky XHT diy 2.4 ghz RF module

Post by JohnRogers »

Many thanks for the advice and help yesterday which I have followed and now have the set working.

After binding and power down then back up with servo's connected I was not getting the green light on the rx until I touched the tx aerial onto the rx aerial. In fact I have to touch them every time I switch on to get it working. Is this normal? the batteries have a good charge and I have the tx aerial standing vertical. Any thoughts would be appreciated

Thanks in advance John
Martin
Posts: 539
Joined: 16 Feb 2018, 14:11
Location: Warwickshire

Re: FrSky XHT diy 2.4 ghz RF module

Post by Martin »

Do you have the right sort of antenna connected to the XHT module? There are SMA and SMA-RP types which have the male and female parts the opposite way round. Make sure that either the antenna, or the connector it screws onto has a centre pin - it's possible to fasten two female connectors together, and you get a good mechanical connection, but no electrical one! :shock:

What you describe isn't normal. If it's not the antenna, then further investigation is needed. Have you tried a range test? Once you've got a green light you can just leave the transmitter on a table and wander off carrying the receiver (with a battery, obviously). You ought to be able to get at least a quarter of a mile away, on fairly open ground, before you lose the green light. Holding the receiver close to the ground at extreme range you'll lose the green light, but it should come back as soon as you lift the receiver back up in the air. If it doesn't pass the range test, don't fly!
JohnRogers
Posts: 14
Joined: 09 Dec 2020, 10:42

Re: FrSky XHT diy 2.4 ghz RF module

Post by JohnRogers »

Hello Martin,

Thank you for your repsonse The antenna looks ok. I will try the range check tomorrow


John
JohnRogers
Posts: 14
Joined: 09 Dec 2020, 10:42

Re: FrSky XHT diy 2.4 ghz RF module

Post by JohnRogers »

During range checking I believe I have found the problem with the rx not receiving signal from the tx

It will not link unless the tx and rx are 4 feet or more apart. In the old days we used to call this swamping.

During the range check I had walked down the road with the Rx connected to battery and servos and at approx 250 yds and the red light came on, on the rx, as I started walking back it went out and there was a glimmer in the green light. I then switched off and back on and the green light was back on.

With the tx two feet above the ground at the back of the house I managed approx 250 yards with the rx at ground level, I had walked under two sets of power lines.

With the tx in range check mode ( press f/s button for 4 seconds, red light off and green on (although not flashing)) I managed 30 yards in a straight line, only a wooden fence in the path.

I did notice that as you move the two apart the green light starts to glow dimmer, it is not as bright as the red light.

I now need to do a range check with two people to check servo movement although I could use the facility on the encoder.

I hope I am now on my way with the project

Thanks again
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