VHF + LEDs = Noise?

[farotherside]

Hey folks,

My old 'Horizon Titan+' VHF finally died, so yesterday I went down to WestMarine and picked up their 'VHF650' radio, on sale.

I hooked it up last night in exactly the same space as I had the old VHF, using the same antenna as before and first the same electrical wiring as before, but later switching to the wire that was included with the new radio as a test.

My problem is that my salon is done entirely with lovely new LED lighting - the fresh new stuff from China, cheap, bright and completely indistinguishable from halogen lighting in warmth. I have five 3w fixtures in my salon currently and plan to expand that by another seven fixtures in the near future.

With the old radio, everything worked great. With the new radio, as soon as the LED lighting is on, the noise goes way up. Because the noise is somewhat inconsistent, the squelch control doesn't do much, and the radio just happily crackles and pops through the squelch.

Before I take this radio back to West Marine, does anyone have any suggestions about what I could do to fix this problem?

[aboon]

drew23,
This may not help you directly with your problem, but I have found that some LED globes do ceate radio interference on HF, less so on VHF. I'm guessing that some have switching regulators to provide a constant current source for the LEDs, which will give them constant brightness as the battery voltage varies, also extend their working life. The interference radiated is less than a fluorescent light fitting, but it is noticeable.

Try wandering around your cabin with a VHF handheld and see if the mute opens as it gets close to the LED lights.
Did your old radio have a metal case? Is the negative power lead connected to the case in old or new radios? Any other differences? Is the braid of your antenna coax still connected to the body of the connector which plugs into the radio?

Good luck with it.

Andrew

[Roy M]

Check out Panbo- The Electronics Weblog for some discussion on this subject: Panbo: The Marine Electronics Weblog: LED nav lights, a fast moving target. It's apparently a common-enough problem that needs to be addressed before switching to these dandy units.

[Kefaa]

I did find the part at Mouser 0431167281

aboon has summerized it nicely. My favorite line from the OGM FAQ page was Older radios or less sensitive radios don't seem to have any issues with interference, so the issue is very isolated as we can tell. So...stop buying new equipment?

As for a test fix - $3 + shipping seems to be worth it. If you do try, I and others would be interested in hearing the results. LEDs are the future for lighting but they are evolving at the same time.

[donradcliffe]

The ferrite chokes and a capacitor across the supply may help if the interference is coming through the power cord. Wiring the VHF directly to a battery (with a fuse) will probably do more.

[Paul Elliott]

Originally Posted by donradcliffe

The ferrite chokes and a capacitor across the supply may help if the interference is coming through the power cord. Wiring the VHF directly to a battery (with a fuse) will probably do more.

Putting ferrites and capacitors as close to the fixture as possible will reduce both conducted (through the power cord) and radiated (through the air) interference. If the suppression components are at a distance from the interference source then the wiring acts as an antenna, turning conducted noise into radiated.

I agree with the suggestion to walk around with an unsquelched VHF receiver to help locate the interference sources. When I install new gear I often do a channel-by-channel VHF check, first noting any noisy channels (which may be the quiet-sounding ones) when the power is off, using this data as a baseline. I then turn on the power to the new device(s) and repeat the test.

[GordMay]

A really cheap portable AM radio is also an excellent RF (& lightning) detector.