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2.4GHz Rx position

Posted: 10 Jul 2019, 23:19
by Jolly Roger
Doing my first 2.4 install and need help please.

I hear carbon-fibre reduces 2.4 receiver signal strength. I have a largely grp fuselage with some carbon tow around the canopy frame and cloth reinforcement around the retract/wing joiner. How close could the rx be to this c/f without major risk of signal loss? Are we talking 10cm? 20cm?...

Second question: I'm actually using twin X8R receivers (connected via a redundancy bus). Does it make sense to have the rxs in different parts of the fus to reduce risk they are both blocked at the same time e.g. put one on the fus floor towards the nose and one on the fus ceiling above the wing root?

Sorry for these novice questions. :oops:

Rog

Re: 2.4GHz Rx position

Posted: 11 Jul 2019, 07:11
by Simon WS
I wouldn't worry about carbon tows too much Rog - just don't put the last 32mm of the aerials (that's the active bit btw) next to any bits of carbon. Since it's your first 2.4 install I'd also "remind" you to place the active bit of the aerials of each receiver 90 degrees to each other.
It is also a good idea to put the other receiver somewhere else if your fuselage has lots of big bits of carbon in it but in your case I wouldn't worry - just orientate the aerials in a different 90 degrees.

Simon

Re: 2.4GHz Rx position

Posted: 11 Jul 2019, 20:59
by Jolly Roger
That's really reassuring and helpful Simon, especially about the antenna positioning. I was surprised the Frsky rxs had nothing in their instructions on antenna placement. I guess it's all assumed knowledge now. Anyway, I should be able to keep the antennae at least 10cm from any carbon.

Thanks again.
Rog

Re: 2.4GHz Rx position

Posted: 16 Jul 2019, 21:21
by Nigel Argall
Roger, I am also a Taranis 2.4 New Member - my Grunau Baby was my first installation. I have thick strips of carbon running down the front section of the fuselage - albeit with big gaps. I recently had the model about 1000 feet up and quite along way out at St Agnes without problems. I DID do a very thorough range check (its buried there in one of the menus) walking all round the model at quite a distance and repeating with model upside down, at odd angles etc. If you do that and all is well... you should be ok I think.

Re: 2.4GHz Rx position

Posted: 16 Jul 2019, 23:44
by Barry_Cole
Hi Nigel,
Welcome to the club...

:D :D :D :D

BC

Re: 2.4GHz Rx position

Posted: 23 Jul 2019, 12:59
by Jolly Roger
Thanks for your input guys.

Another question.

With 2.4GHz, does anybody still use ferrite rings in servo-wiring?

Back in 35MHz, I fitted these to models with long servo wiring, just before the wire entered the rx. The idea was that it prevented wires acting as rx antennae and interfering with the RF signal (I never saw evidence the rings helped, but for a few pence, fitted them just in case!)

Rog

Re: 2.4GHz Rx position

Posted: 23 Jul 2019, 13:10
by Peter Balcombe
Roger,
I think you will find that back in 27/35MHz days, the long wing servo wires lengths came out at somewhere near 1/4 wavelength - so picked up anyone’s Tx signals & fed it back to the Rx, causing interference.
Not the same issue with 2.4GHz as the frequency is 100 times higher.
Fit rings if you like, as they will not do any harm.
Peter

Re: 2.4GHz Rx position

Posted: 23 Jul 2019, 16:11
by Jolly Roger
Thanks Peter - that sounds like a pragmatic approach although I'm still wondering if ferrite rings are at all helpful when 2.4 has such a reputation for interference-rejection.

Re: 2.4GHz Rx position

Posted: 23 Jul 2019, 16:43
by Peter Balcombe
Hi Roger,
What I meant was that although I don't think that rings will do anything at all for you at 2.4GHz, they will not adversely affect the radio, so if you already had them & didn't mind the space etc. etc., you didn't need to remove them.

Re: 2.4GHz Rx position

Posted: 23 Jul 2019, 17:34
by Jolly Roger
That's a helpful clarification.

Actually I'm shortening all the servo leads as they'll now run to a redundancy bus, so will remove the rings then. Should tidy up the install a bit. :)

Thanks again.
Rog