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Radio noise at high rpm...

Posted: Mon Mar 24, 2014 1:01 pm
by IceAge
Please, I need some advise with my radio/intercom on the trike................ no a new system is not an option at the moment..

My setup consists of a v-rabit, buzzcom intercom and headsets with a vertex VXA210 radio. I also have a vertex approved charger for the radio to keep charge up.

During warmup and while taxiing (RPM 2800-3500) my comms is crystal clear, ie. communication between pilot and pax is 110% and with other planes 5/5. However, during flight (RPM 4800-6200) the noise in both pilot and pax headsets is at a level that communication is almost impossible and just to hear the other pilots requires serious concentration making flying not very pleasant. I have tried different headsets as well as flying with the charger plugged in/out without any success.

Is there perhaps a loose electric connection somewhere? Where should I look? Why the noise only when rpm's are high.

Any advise (except buying a new system) will be highly appreciated

Re: Radio noise at high rpm...

Posted: Mon Mar 24, 2014 1:07 pm
by nicow
Check/replace your Spark plugs...

Re: Radio noise at high rpm...

Posted: Mon Mar 24, 2014 1:50 pm
by IceAge
Nicow

Thanks for the advise but, I replaced the plugs less than 5 hours ago at 200 hours. However, during this time I replaced all the rubber grommets on the lead wires as well. Maybe there is a bad connection on one of the leads. I will check over the weekend.

This is why I like this forum so much...... good sound advise.

Thanks

Re: Radio noise at high rpm...

Posted: Mon Mar 24, 2014 2:24 pm
by nicow
It can still be a bad spark plug.

Re: Radio noise at high rpm...

Posted: Mon Mar 24, 2014 4:57 pm
by gripen
Have you checked the squelch on the radio?

Re: Radio noise at high rpm...

Posted: Mon Mar 24, 2014 8:28 pm
by vanish
check ur capacitor, if it deformed or cracked, replace

Re: Radio noise at high rpm...

Posted: Wed Mar 26, 2014 7:59 am
by John.com
vanish wrote:check ur capacitor, if it deformed or cracked, replace
Hi Vanish!

Please can you expand on this . . . . what capacitor, where?

I am asking as I have a similar issue! :shock:

Many thanks,

John.com

Re: Radio noise at high rpm...

Posted: Wed Mar 26, 2014 7:57 pm
by vanish
hi john, when opened my pod to upgrade instruments to analog, found the rotax spec capacitor swollen & started splitting open. on speaking to some of our guru's i was informed that was the reason for my average 3/5 radio read, worst was at high revs, find it inside pod, seen them on the windlas open under the motor, size of a d battery. replaced & whala radio 5/5
keep on talking, enjoy the flight
steve

Re: Radio noise at high rpm...

Posted: Wed Mar 26, 2014 8:37 pm
by John.com
vanish wrote:hi john, when opened my pod to upgrade instruments to analog, found the rotax spec capacitor swollen & started splitting open. on speaking to some of our guru's i was informed that was the reason for my average 3/5 radio read, worst was at high revs, find it inside pod, seen them on the windlas open under the motor, size of a d battery. replaced & whala radio 5/5
keep on talking, enjoy the flight
steve
Oh brilliant, thank you! I had always wondered what that large capacitor was for.

Where would one buy a replacement from, Comet? You say that it is a Rotax part?

Thanks again, John

Re: Radio noise at high rpm...

Posted: Wed Mar 26, 2014 8:38 pm
by ZULU1
Been out of action but just picked this up...try one of these fellows across the battery/regulator

http://www.mantech.co.za/ProductInfo.aspx?Item=72M0037

That should work...

Re: Radio noise at high rpm...

Posted: Thu Mar 27, 2014 8:25 am
by nicow
gripen wrote:Have you checked the squelch on the radio?
This can be the problem....

Re: Radio noise at high rpm...

Posted: Thu Mar 27, 2014 8:34 am
by ZULU1
Nico, so correct, but before we add more info, need to confirm the exact radio, if its a 210, dont think they have a ANL function like the others, then it becomes hard work to fix. The VXA220 and the FTA230 and the 300 etc have this function which will nail it.

Re: Radio noise at high rpm...

Posted: Thu Mar 27, 2014 8:36 am
by John.com
ZULU1 wrote:Been out of action but just picked this up...try one of these fellows across the battery/regulator

http://www.mantech.co.za/ProductInfo.aspx?Item=72M0037

That should work...
Greetings and thanks Paul!

For the laymen like myself, would you mind explaining what this capacitor actually does, i.e. HOW it reduces interference?

Many thanks,

John

Re: Radio noise at high rpm...

Posted: Thu Mar 27, 2014 8:56 am
by ZULU1
John and others, if you can imagine a single cylinder compressor or water pump, this will normally be drive by a rotating device such as a motor or enjin etc. it will produce a "pulsed" output, ie spurts of pressurised water or air. We all know that this output is then normally fed to a receiver or water tank. The air or water output is stored as a mass of water in that vessel. Then when we drain that mass of water or air it will be the same pressure as the input, but by means of mass it will "smooth out" the original pulsed input. The sheer mass of material will eliminate the pulses. The capacitor is a similar principle. I think that is the easiest way to describe the basic principle !! Sure there are many other "physics" required but that is the basics. google Capacitor. For info a simple timer in electronics uses a capacitor, the drain rate determines the time, ie draining a water tank and controlling the time by means of a tap.

Other devices to eliminate noise are rf beads, inside a chatterbox there are loads of them, this can be known as a black art and not so easy to fix...

Re: Radio noise at high rpm...

Posted: Fri Mar 28, 2014 8:13 am
by IceAge
Paul,

The 210 does have the ANL option and is always selected. I normally set the squelch on the radio between 6 and 8.We have a radio tower close to the airfield which causes interferance hance the high setting.

I will check all the suggestions made thus far over the weekend and hopefully one will stand out as being my problem......

Fly safe