Radio interference on certain frequencies

[Bumpy]

Hi Demon

I have been experiencing the same thing on my radio (Icom A4) on 124.8 and have discovered that it is my Garmin 296 GPS.
Please explain a bit more about these snap on things, how it works, looks and costs.

Regards

Phil

[Junkie]

SNAP ! - I fitted a 196 about 2weeks ago in place of my GPS3 and *&%^&%$ all hell broke loose on certain freq, didnt matter what i did with Squelch, screening, etc, etc...
My fav AP buddy came along and advised to split the power source for GPS from radio (both on same) and take directly from Battery, which i duly did and VOILA problem solved instantly

Thanks Andre

:D :D

[ZULU1]

I use ferrites also but normally wrap them around the radio infeed line to the intercom box, they are tuned for the frequency required and looks like you aced it first time. I manufacture power supplies for the mainly ICA6/24 range with a voltage regulator and line choke. That also stops a heap of power derived noise. Good idea to angle the antenna forward from the airframe as this also helps...

eish Zulu1

[Bumpy]

Hi Demon

Thanks for that generous offer, could I twist your arm and get you to bring two of them to the Africa Cup this weekend I will fly in on Saturday and pic them up.

Regards

Phil

[John Young]

I will take a pic on the weekend, cost to microlighters members is free, i have about 40 of them

Hi Demon,

Would be really obliged if you could keep a couple back for me 'till we next meet.

Thanks a mil & regards
John ZU-CIB

[Bumpy]

Thank you very much

Look forward to meeting you

[Bumpy]

Hi Demon

Thank you very much, we received the four ferrites at Numbi on Saturday afternoon and tried all Sunday to get it to work.
(We tried various combinations and positions)

Unfortunately nothing seems to help the extreme interference we are getting on our Icom radios (1 x A4 with single jack speak easy intercom) and (1 x A24 with Buzcom intercom) caused by our Garmin GPSMap 296.

Anyone have a suggestion

[Skimmer]

Struggled many years ago trying to silence an old Magellan (including painting the inside of the plastic housing with conductive paint.) What worked was coiling up the power supply lead to the GPS to act as an RF choke and stop RF escaping down the power line. We coiled it on a dowel rod very close to the GPS - maybe try your ferrites on this lead or feed the GPS through small RF chokes close to the GPS. If you have a data lead into the GPS this could be providing an escape route for the stuff. Try running the GPS on internal batteries to see if this is where it is coming from.

The same happens on an antenna lead - RF from the 'electronics bay' runs up the outside of the antenna lead and into the antenna - what helps here is a decently matched antenna with ground plane (or something that serves this purpose). This also stops transmitted RF running back and causing $*&^&* with the intercom.