Am/Fm car radio interference

[mhouse]

My set up is the normal Clarion car type am/fm radio. Via antenna splitter.
Reception is great until I turn on some of the internal LED lights or plug in USB chargers of which I have tried many.

I have a selection of the wrap around ferrite split things from old VHF radios , any suggestions on where to fit these or if they would work would be appreciated.

Ta

 

[earlybird]

I suffer in a similar way. My theory is that the interference is injected onto the boat 12v. supply, hence no real cure. I'd be interested in better informed opinion.

 

[Seashoreman]

My set up is the normal Clarion car type am/fm radio. Via antenna splitter.
Reception is great until I turn on some of the internal LED lights or plug in USB chargers of which I have tried many.

I have a selection of the wrap around ferrite split things from old VHF radios , any suggestions on where to fit these or if they would work would be appreciated.

Ta

My workshop radio reception has been really terrible over the last 2/3 days down near River Alde, Suffolk.
I blame the hot weather, it seems to wander about. Fairly rubbishy wire type ariel.
Could it be the transmitter?

 

[GHA]

I suffer in a similar way. My theory is that the interference is injected onto the boat 12v. supply, hence no real cure. I'd be interested in better informed opinion.

I've had success with cheapo DV buck convertors by putting maplin capacitor on the input and output, forget what size - just experimented with some til a radio sitting next to it sounded OK.

 

[Daverw]

This is a common problem with low quality LED and chargers. Many have badly designed switch mod power supply circuits, led lights with resistor voltage drops fitted don't do this but illumination then varies with battery voltage.

You will find it very hard to filter or suppress, to test if it's 12v circuitry power the radio direct from a small separate battery, suspect you will find its airborne interference

 

[GHA]

, to test if it's 12v circuitry power the radio direct from a small separate battery, suspect you will find its airborne interference

A RTL TV dongle for under a tenner will give you a spectrum analyser to have a good look at whats going on over the airwaves.
Assuming you have a laptop.

http://www.rtl-sdr.com/spektrum-new-rtl-sdr-spectrum-analyzer-software/


Edit- That's fantastic! So this is a cheapo RTL TV usb dongle antenna being moved from almost touching a bedazzled LED strip to about a foot away on the marine VHF frequencies.

 

[neil_s]

I had similar problem with the 12v power adaptor for my Dell laptop. I noticed that the 12v supply for the cig lighter socket originated at the switch board and ran parallel with the supply to the radio. I moved the cig lighter socket to the other end of the saloon and wired it directly to the main power switch (via an in-line fuse). Radio interference now much reduced.