LED Noise?

[clausont]

Hellosailor - I take your answer as the one to go by - "No". You are correct in my having changed the entire fixture, not just replacing bulbs with LEDs.
Fairbank56 stated what I had in mind when I said that I guess I could understand some noise from the LEDs - but I would not know how much noise an LED could emit. Glad to know that it is the driver circuit.
Shall I say that this thread has been very "enlightening" on LEDs? (Ok, so that is bad)
I truly appreciate everyones input here. I have learned a lot from this. I will do some more testing, contact the manufacturer to see if there is a solution and worst case scenario, replace the fixture once again with a known good (quiet) product.
Thanks all.

[hellosailor]

Ask the maker--with a straight face--how soon they'll be sending someone over to go aloft and change the fixture for you. (Hey, maybe you'll get lucky.<G>)

When they finish having that fit, just remind them that since YOU will be going aloft two more times to replace the problem child, perhaps they could just send you an advance shipment on a replacement--if they have one without RFI problems. It's not totally unreasonable to want to save a trip to the masthead that way.

[clausont]

LOL! I like that! I think I will do just that too.
Maybe I can get it reduced to just one more time up the mast
Thanks

[S/V Antares]

Hmmmm? Microship.... do you think moving the LED driver (Resistive or PWM) down mast and sending the lowvoltage current limited power to an LED aray would help? Is the noise radiating the antenna or is it on the 12 line?

[Microship]

Originally Posted by S/V Antares

Hmmmm? Microship.... do you think moving the LED driver (Resistive or PWM) down mast and sending the low voltage current limited power to an LED aray would help? Is the noise radiating the antenna or is it on the 12 line?

Hi... the worst noise will likely be between the PWM driver and the LED itself; there is some on the input side, but that's pretty easy to fix (if necessary) with a big capacitor close to the driver (that sources current locally instead of requiring pulses all the way from the battery). A low-ESR type like a tantalum should help (keep polarity correct)... value not too critical.

But that may not help; the bigger problem is between the driver and the LED. In most products, that's not much of a distance... they are often built into the same enclosure (the homebrew one that caused me trouble was not, which was my mistake). Killing noise there is much harder, since you're really trying to quiet a train of square-edged pulses, which contain energy at every odd harmonic up into many megahertz.

Hellosailor made an excellent point about the masthead ones being the worst. I have not used any myself, but parking a PWM circuit next to an antenna is almost guaranteed to cause problems unless it was extremely well designed.

Before hauling one up the mast, it is worthwhile to test it on the bench... power it from some long wires, just to keep it realistic, and use a VHF handheld to probe around. This is not the best tool, as the harmonics may not fall on any of the channels; an AM radio will be much more revealing (and an SSB more so). Once you find a birdie (undesirable signal clearly caused by the circuit), you can get a sense of how bad it is, if it yields to capacitors, or if the whole thing should go somewhere besides the near-field zone of the antenna.

Cheers,
Steve

[S/V Antares]

Thanks Steve, Really good info. I have not noticed any "Fur" on my VHF but will check it out tonight.
Will

[S/V Antares]

I have an OGM tricolor with strobe and checked it out last night. I cannot detect any noise when monitoring or transmiting (to a boat in the same marina). OGM does mentiion this issue in their Q & A tech section

Orca Green In The Rigging: Q: I recently read that some LED lights and particularly OGM’s tricolor/anchor LED light causes some problems with VHF interference.

As an aside, I have also seen (heard) noise on others VHF's when their inverter is on , Seems to be a slight Hummm,

[hellosailor]

Am I the only one whose eyes hurt [sic] with striped afterimages after reading that Orca web page?

Will, moving the driver down the mast would be problematic. Power loss in the wiring would be unpredictable unless you knew the wiring and length being used, and that would make precision driving of the LEDs impossible, plus the longer wire would radiate better (more noise!) and be a better entry point for lightning surge damage.

If they've really had only a half dozen problems, it could be something as trivial and difficult to deal with as some components from one supplier being marginally out of spec. (Or maybe those half dozen sailors are the only ones with good antennas.[g])

[Therapy]

Originally Posted by S/V Antares

Orca Green In The Rigging: Q: I recently read that some LED lights and particularly OGM’s tricolor/anchor LED light causes some problems with VHF interference.

From there is

"... If you have already installed one of our TriAnchor lights and do happen to encounter any interference, please contact us and we will work with you to correct it...."

We "armchairers" want to know the definition of "work with you".

Plus they said it is "... (only from customers who have our TriAnchor light), ..."

[colemj]

Originally Posted by Therapy

From there is

"... If you have already installed one of our TriAnchor lights and do happen to encounter any interference, please contact us and we will work with you to correct it...."

We "armchairers" want to know the definition of "work with you".

Plus they said it is "... (only from customers who have our TriAnchor light), ..."

We have an OGM trianchor. No problem with RFI, but for grins I called and asked about that type of problem and what to do if I experience it. They overnight shipped me two ferrites - one to install on the wire leading into the light (trip up mast), and the other in case I dropped the first one overboard.

The tech guy I talked to was very pleasant and helpful. Although I had difficulties getting any response from them by email, they answered the phone promptly and connected me straight to engineering.

Mark

[Therapy]

Originally Posted by colemj

We have an OGM trianchor. No problem with RFI, but for grins I called and asked about that type of problem and what to do if I experience it. They overnight shipped me two ferrites - one to install on the wire leading into the light (trip up mast), and the other in case I dropped the first one overboard.

The tech guy I talked to was very pleasant and helpful. Although I had difficulties getting any response from them by email, they answered the phone promptly and connected me straight to engineering.

Mark

Outstanding!!!

[S/V Antares]

I have no noise on my VHF with the OGM on or off. Even the strobe does not appear to generate noise. I wonder if antenna quality is part of the equasion.

[colemj]

Originally Posted by S/V Antares

I have no noise on my VHF with the OGM on or off. Even the strobe does not appear to generate noise. I wonder if antenna quality is part of the equasion.

The tech guy at OGM told me they have traced it down to one or two specific models of VHF radios.

Mark

[Microship]

Also, with the squelch and capture effect of FM VHF, low level noise may not be at all noticeable. If you open the squelch and check all channels, still hearing nothing, then you're probably fine (noise may still exist, but have its harmonics conveniently out-of-band).

SSB will be more sensitive, especially with a backstay sloper.

Steve