Scale Soaring UK

There was mention of keeping 2.4ghz aerials away from servo leads but with the FrSky Gr8X the aerials are short and channels 7, 8 come in from the other end onto the board. The result is less chance to get the aerials into clean air. I do get glitching when at short range.

I understand that the exposed aerials are shorter and designed for the RX, can other lengths be used on it to get them away from interference?

M

Futaba sells different length aerials to solve this problem. Actually, it is the same length aerial but on an extended piece of co-ax cable. It clips onto the aerial terminal on the receiver RX board so no soldering required.
I do not know if they will fit the Fr-Sky boards.
AEB

FrSky sell their own longer aerials, they are available from T9.

They do plug on, but I think they may use 2 sizes of plug. Check with T9 before ordering.

Make sure your glitching is dot down to a dodgy servo. One bad one can make them all glitch. Been there done that.



BC

Yes, you will be pretty sure to have the RF link dropout with the Tx right next to the receiver due to swamping (overloading the receiver).
No problems when moved a couple of feet away.
My kit usually reports “telemetry lost” when the Tx is very close & recovers as soon as the Tx is moved a foot or so.

Also, always best to have the Rx itself away from the ESC in an electric power setup as radiated noise from the motor drive/BEC high power switching elements can break into the Rx circuitry, even if not directly via the aerials/front end.

Note that separate SBEC (switching BEC) regulator units may also generate significant RF noise - the ferrite ring on the output lead is there to reduce conducted interference, but it doesn’t stop radiated noise!

The noise power reduction is a square law effect, so doubling the distance reduces signal levels by a factor of 4.

Thanks all, the point I was trying to get across was that the GR8X RX has different length exposed aerials (the unsheathed length is different, from a forum) and is designed so the only onboard software copes with this and due to the design of the board servo leads come onto it from both ends making it hard to get the short aerials away.

Yes I can get longer aerials but as far as I know the exposed section is also longer, Will longer length exposed aerials work the same?

M

Frsky have been using 1/4 wave, 1/5 wave, and 1/6 wave aerials. I will check and see what you need. I have not used Ch 7 & 8 on these Txs yet so have not had your problem. If you take the aerials away to each side that should be far enough. Do you get glitching when you are outside.??

I will check about the aerials.

BC

Thanks Barry, yes the glitching is when I am indoors, I’m not overally concerned it’s just annoying. The issue with the short exposed aerials and trying to distance them from the servo leads must be fairly new. I got one of the first ones, I think. Up till now I have brought the extended ones without the paddles for the other XR8 RX which work well even when I push them out through carbon fuses.

Yes I have seen your link to the longer GrX8 ones.

Do you have florescent lamps indoors?. I used to get glitching in the workshop until I changed the tubes for LED ones.

BC

Yes, but not on during the day.

No, That is Daylight using, Electricity saving.....



BC

Since we've drifted off topic anyway, we switched our fluorescent tubes over to LEDs earlier in the year and they do seem very good. Also the tubes are plastic rather than glass - a point which I appreciated when I clouted it with a wayward wingtip recently! One thing I haven't tried though - will my rev counter work under mains LED light?

Trevor wrote: ↑13 Oct 2018, 09:29One thing I haven't tried though - will my rev counter work under mains LED light?

No it will not, my workshop is still doing 3000 RPM....



BC

Looking forward to your next speedy build then Barry as you're already running at 3000 rpm you must be almost ready for covering !

Geoff

How come you`re not upside down Motley

I am Tony,(just avoiding incontinence "old Bat joke") fortunately I've got access to the forum even in the outback here in good old Aus !

Geoff

S’funny it works here in Italy as well......... the spinning might be down to the wine?

Hi all,after a minor hiccup on recovery road l am finally back in the workshop,though under the eagle eye of the mem sahib ,the B4 is now firmly back on the bench with not too much left to do,but l fear the maiden will be deferred till the warmer spring weather ,l do,however have a question regarding the placement of the antennae....l plan on using dual recievers and battery packs via an frsky RB10 unit,the rx,s will be side by side in a purpose made cradle,therfore l am a little concerned as to the routing of the antennae,l understand that they need to be at right angles to each other,but as l am dealing with four of them in close proximity to each other,l wonder if there may be some problems there ,l am using a pair of xr8 rx,s as they are to hand,l will also be adding a stand alone vario,although l will,in future be using the r-8r with built in vario,many thanks guys,pics of the b4 to follow,jack.

The Spelling Police strike again...

Fluorescent strip lights can cause radio interference, as can LED lights when used with a LED dimmer.
Lights used without dimmers controls will be ok.
You can also get dropouts with some 2.4GHz radio sets if the Tx is very close to the receiver (usually within a foot or so) - which is easy to do during a bench setup.