LED anchor light bulb interferes with VHF

Maine Sail · Sep 15, 2011

jviss said:
This year I installed a Dr. LED Pole Star anchor light bulb. I noticed now that when the VHF is on and the squelch set normally, when I switch on the LED, it breaks squelch and pushes noise into the radio. I have to close the squelch about 1/8 to /14 of a turn to compensate.

Anyone else? Comments?

Thanks,

jv

Pretty typical of LED's. If you need to TX just turn it off then back on when done. For interior lights the Sensibulbs have excellent noise reduction circuitry but most nav lights, that I know of, don't..

Rick D · Sep 15, 2011

Yup...

...that is exactly what changed my mind about installing a masthead LED combo running light. I can live with an LED anchor light since I generally don't use the VHF when anchored.

Rich Stidger · Sep 15, 2011

Well, after reading this thread, I just had to try to duplicate the results. I installed a Dr LED two years ago just before they came out with the single LED Polar Star anchor light. So mine is the one with many LEDs- I forget exactly how many.

Anyway, I turned on my VHF - Standard brand about 13 years old, set it to channel 69 and turned the squelch down until it squawked and then up just to silence. I then turned on my anchor light and there was still silence.

Maybe the single LED anchor light is noisier than the older multiple LED model?

Bill Roosa · Sep 15, 2011

Older versions use those resistor things and let the LED dim and brighten with changes in voltage. The newer ones have voltage regulators (with MHz oscillators) and so emit radio waves but do not brighten (but may dim) with changes. some also use PWM to drive the diodes which can also emit radio.
I'm thinking that a cap between the power and ground will solve the problem.

Rich Stidger · Sep 15, 2011

I would believe that there are a number of variables that would affect the amount of electrical noise on the system. Certainly the device itself is a big factor, but so is the ground system and the quality of the connections in the DC system. A poor connection or crimp would present a higher impedance to both AC (noise) and DC signals.

The fact that I don't see any noise, or at least it doesn't affect the squelch on my radio doesn't mean that someone else may not have the problem. I posted my result only to suggest that the newer one-LED design might be a noisier circuit, hence explaining the OP's issue.

FourPoints · Sep 15, 2011

Hmm, I installed the Dr. LED feston star white bulb in my anchor light this spring. Haven't noticed any problems with the vhf yet, but will be sure to check things out before my dad and i go out for a 4 day cruise next week...

edit: the anchor light was pretty much the only bulb on the boat that was not yet converted to LED, all my cabin and NAV lights have been LED for 2 years now and I've never noticed any problem. Cabin are Maine's preferred Sensibulb, and the NAV are all the Dr LED Festoon Star, color appropriate of course.

Benny17441 · Sep 15, 2011

If it is a nuisance, turn the anchor light off before using the radio. Likely not a problem during the day.

Shell · Sep 16, 2011

LED

I' ve used LEDs in my interior and nab/anchor. ever had any noise.

Shell · Sep 16, 2011

Sorry, never had any noise issues.

Fred Villiard · Sep 16, 2011

I have some Dr LED bulbs, Polar Star 40 Tri & White, Festoon Star white, and Polar Star 25 Bi.

I'll bring them into the lab in the next couple of days and run them in the EMI chamber and plot the RF radiation patterns, under different conditions.

I'll post the results when done.

Fred