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Radio interference at Bray Head (35 MHz)

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Fergal Gordon:
HI everyone,

A couple of weeks ago I flew at Bray Head on a nice evening with a fresh breeze.  Myself and Ed flew about 500 m south of the cross, as there were 6 para-gliders there.

3 or 4 times during an hours flying I had some glitching.  I have never had glitching before, except for the time I did not extend my antenna before take off.  Initially I though it was severe turbulence, but the wind was not that strong and you would not expect much turbulence coming from the sea.

I landed and did a radio check, all OK.  I switched off the Tx and there was not a sound out of the servos.  Everything seemed OK.

I completed another couple of flights, again with intermittent glitching.  The last incident was close in at eye level and this one was more valiant and at one stage sent the glider towards the sea.  Control was reestablished, followed promptly by a safe landing.

I checked it out at home and all seemed to be OK and have flow since on the slopes in Wicklow without any problem.  At this stage I am guessing that the problem came from the overhead electric cable of DART line.  We we standing back from the edge and were not aware of the trains below, so I don't know if there was a train passing when the glitching occurred.

Here are the technical details of my system:

Tx: Multiplex Royal Evo 9, 35 MHz, synth, operating on Ch 80

Rx: Multiplex Rx-6-Synth light, operating on Ch 80

Servo: Hytec HS82MG x 2, Hytec HS125MG x 4

Ed was flying on 2.4 GHz and had no problems.

Does anyone have any similar experience at this or similar locations?  I presume I should move to 2.4 GHz to fly safely at Bray Head, or is there some other way to address this problem.


Best regards,


Fergal

Alan_Perse:
Hi Fergal. Welcome to the Forum.

Just wondering what model you were flying?

I had similar problems like that before with my DHLG. I think I told you about it before. Thanks to Ralph I have finally solved the problem. My receiver antenna was to close to the mess of servo and battery cables in the fuselage. Just rooting it away solved the problem.
 
I know that you never had any problems before with your models, so this may not help. So it could be an interference problem at Bray.

Alan.

rogallo:
Hi Alan and Fergal

HI Tension Electric Cables CAUSE RF interference, Stay away.

We have power lines scattered across the farm we fly in and suffer from interference on 35mhz near the cables.

Also stay use lower channel numbers (I am on 80 :P  )

Just me twopence worth

Ralph

joe:
Hi Fergal.
Maybe someone was flying at the Shankill club on your channel?
Shankill club is just south west of the sugar loaf. If they had a powerful TX I guess it could cause problem???

JohnPearson:
Hi Fergal

Looked at the possible reasons you give for problems on 35MHZ, here's what I think!!

1. We fly of the beach beside a railway line at castle rock,trains pass close to us, and we have had no interferance on 35 or 2.4.
2. Power lines, I lost a small electric jet on 35, after flying under a local power line a few weeks ago, the model never give me any problems before that day.
3. Running your antenna near other cables can cause big problems, I always place the antenna out side the fuselage.
4. mobile phones can cause problems to 35 using synth system, i.e phone in your pocket when flying, The BMFA do not allow any mobiles on the flight line at any shows in England.

We had a  problem at our club with operating on 35MHZ over the last year, with models crashing for no reason and bad interferance on some channels, we got equipment in to check out the flying site for local transmitters operating near the 35 band and strong transmissions on other freq's, we found nothing, therefore all our pilots fly on 2.4, problem solved.

I think the idea which Joe put forward about shankel may be possible, to check barrow a channel monitor if possible when you next go to bray.

Hope some of this info helps

johnp

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