LED VHF Interference

[Lundylad]

Looking to fit LED Nav lights and have read about the interference from them on AIS Vhf and FM radios.
Would be usefull to know what peoples experience of this is and what to avoid if possible.
Thanks

 

[haydude]

Keep the light far from a VHF antenna. Some LED lights are better than others when it comes to interference, so test them first.

In general you can compromise as follows:

BEST OPTION:
Deck Level navigation lights: can be LED no interference problem
Steaming light half mast: can be LED, no interference problem, however not really necessary because you are likely to motor.
Antenna on top of mast next to Anchor light for both VHF and AIS (splitter)
Anchor light on top of mast: if LED it will interfere with VHF, but...do you care about interference when you are at anchor? If you do, then you want a normal light bulb.

ALTERNATIVE:
Tricolor on top of mast: LED bulb NOT ADVISABLE because will be on at the same time as VHF/AIS
Separate AIS antenna on pushpit: install as far as possible from stern light. In any case it is best to use the mast top antenna with a good splitter

 

[William_H]

VHF antennae

I would disagree in that it is best to have an AIS antenna on the pushpit. This can then double as an emergency antenna (especially if the mast is lost) and you don't need really top range for AIS.
Sorry I have no actual experience with LED and VHF interference. Obviously the cheap resistive current limit types will not interfere. The types rated as good for 10 to 15 or 30 v input are the type which may interfere having electronic switching for current control. good luck olewill

 

[youen]

I just had the problem.I put an AIS transpondeur via a splitter to the masthead vhf,as soon as I switch the tricolor mast head led i lost the ais signals.So I swap my old led for a new Mantagua one and its quite perfect now,but I think it remains some interferences for far stations

 

[whipper_snapper]

I have no problems with a lopolight at the masthead, inches from the VHF aerial.


Has anyone tried a ferrite on the wire to the LED? It depends whether the RF is 'airborne' or being transmitted throu the dc wiring. Maybe try powering the led from a self-contained battery for a test and see if that makes any difference. If it stops it completely then a ferrite is likely to work.

 

[Conachair]

I have no problems with a lopolight at the masthead, inches from the VHF aerial.


Has anyone tried a ferrite on the wire to the LED? It depends whether the RF is 'airborne' or being transmitted throu the dc wiring. Maybe try powering the led from a self-contained battery for a test and see if that makes any difference. If it stops it completely then a ferrite is likely to work.

Same here with lopolight. Also I've just tried a handheld touching a bedazzled led lamp with no apparent difference. Maybe cheap circuits are worse.

 

[wooslehunter]

There are two ways to drive LEDs. You can simply connect several LEDs in series until the voltage drop across them is just less than the minimum voltage you have to drive them. Then you add a series resistor to regulate the current. It's not that good at regulating the current if the voltagr changes & not the most efficent in terms of power. But it is cheap & noise free.

On the other hand, a switched mode system can be can be built into the bulb. If desigend right, it's more energy efficient & regulates the current better. But it's more complex, expensive & can be a source of rf noise.

So if you have bulbs with just LEDs & resistors, they will be noise free &n o need to worry. If on the other hand they are switchers then they may cause interference.

Unless you can see what's inside, it's going to be difficult to know what you have. The place you buy them may know or be able to tell you where they're made & the manufacturers could say. But, many of these things are made in China & sourced through multiple hands.

The easy way woudl simply to light up a bulb & hold it next to the VHF antenna. With the bulb off, set the squelch so the radio is just quite. Check all channels. Then light up & do the same.