radio interference from fridge.

[Bav32]

If I'm listening to my FM radio in poor reception areas, I suffer from interference when the fridge runs.
I've made a quick attempt at fitting a choke in the 12 volt leads and also tried a ferrite ring but no improvement. Proved it was not the fan by disconnecting.
Before I try every choke and capacitor I can lay my hands on, just wondered if any forumites have had success in resolving this.
Fridge is a Coolmatic, Compressor is a Danfoss.
Arial for the radio is via a splitter with AIS antenna.. which both work well apart from this problem.

 

[Billjratt]

If it's a "chirp-chirp" when it starts up it''s the Danfoss controller and we all suffer from that problem. though I've not heard it on VHF, only HF (14.303)
I tried chokes etc. and was going to make an aluminium screen, but the radio is pending repair so I never got round to it. Waeco acknowledged the problem years ago but obviously haven't managed to overcome it.

 

[PotatoNavigator]

There is some good advice here:

http://www.dieselduck.info/machine/03 electricity/radio_interference.htm

 

[Bav32]

All ,
Thanks for the feedback.
I've also been speaking with a fellow yachter who admits to having to switch the fridge off to listen to the radio.
I used to deal with radio frequency interference in a previous life and trust me it's not all science. A great deal of poke and hope with lots of chokes ferrites and capacitors goes on before you get lucky.
I'll contact Danfoss for their thoughts,and to see what changes they made to get the kit through CE approval and feedback any progress.
I'm determined to get this fixed!

 

[GHA]

Nu

All ,
Thanks for the feedback.
I've also been speaking with a fellow yachter who admits to having to switch the fridge off to listen to the radio.
I used to deal with radio frequency interference in a previous life and trust me it's not all science. A great deal of poke and hope with lots of chokes ferrites and capacitors goes on before you get lucky.
I'll contact Danfoss for their thoughts,and to see what changes they made to get the kit through CE approval and feedback any progress.
I'm determined to get this fixed!

I bought the metal cover they do for the control, unit - made no difference. So the fridges gets turned off to receive weatherfax, fm radio is OK though.

 

[rob2]

I'm no expert on RF, but have seen many exemplary installation with neatly bundled wiring which suffered all manner of interference! My two basic principles as a starting point is to ensure the 12V source for the radio is a separate feed from the battery and that neither the antenna feed nor the power feed share a route with that for the fridge.

I once rebuilt/modified a test rig which handled very small signals, all the wiring was simply tossed behind the test bed as a random heap. When I came back grom my holiday, the apprentice had been charged with tidying up and he'd done a superb job of bundling all the wiring into conduits. Unfortunately the rig no longer worked until I cut the cable ties and threw the wires back onto the floor!

Rob.

 

[Bav32]

An update.
Determined to make progress on my problem I spent a wet afternoon poking about.
First thing I tried was using a mains power radio, tuned off station to determine if it was airborne
( radiated) interference. No interference.
Next turned my attention to the antenna which goes via a splitter for the AIS.
Unplugging removes problem. Progress.
Turns out that the "neat" coil of coax from the splitter that I stowed in the compartment behind the radio now had a couple of wires passing through the coil.
My fault of course when re running cables for another job.
Schoolboy error on my part although I realise there should be separation, it's sometimes hard to achieve.
I'll now try a separate FM radio ariel ( car type) and abandon the splitter if that works.
Thanks for the responses and hope my error may help other.

 

[rob2]

Good to hear you're making progress and even better that in reporting back it gives hope and guidance to others. Everyone should take note of the way Bav has thought through the issues and found ways to eliminate each possible source until he found the trouble. Mind you, had the interference come through ikmmediately on the portable radio, ther may not have been a cure!

Rob.

 

[LadyInBed]

Are you mounting your FM antenna outside or just 'laying' it in a cupboard?
Coils of wire are great for picking up interference