Noise on VHF

[johnt]

Does anyone else suffer from broad band noise that is intermittant and cannot be squelched out?

I have been told that it is caused by mobile phone tranmitter towers and is worst close to them (within 5 miles or so).

If it is its going to cause problems as it makes any signal unreadable

My radio is a navico 6300s

 

[Bergman]

Most likely your VHF has a problem, do other radios in the area have the same symptoms? Is it a fixed set or a handheld?

Not likely to be cellular radio transmitters, they transmit on a much higher frequency than VHF and have very stringent EMC standards.

If other sets locally suffer similar things try calling the RA who may be able to help.

Failing that try to contact some local amateurs with 2meter directional antennas who may be able to get a fix on the source.

www.rsgb.org should give you a local amateur radio club who may be a start.

 

[kimhollamby]

Check both the radar (if you have one) and the fridge on your own boat.

Does the problem start after a few hours of operation, especially on warmer days? Know it sounds absurd but had a problem of this kind with a Navico set that was very sensitive to onboard interference; in this case my boat had an older radar fitted that got electrically noisier when it reached a certain temperature. To make matters worse it confined its interference to the same frequency as VHF Ch16, which made dual watch operation impossible.

 

[johnt]

no radar no fridgeand it happens with everything but the radio switched of and its all channels, also straight from switch on, and it doesnt happen offshore! (can you call halfway across the wash offshore?)

 

[kimhollamby]

Sorry the other tips were useless but I would be tempted to get the radio and aerial installation checked anyway, especially if you discover that others around you are not getting hit in the same way. Aerials in particular are a common problem area, although usually that shows up in terms of poor transmission and, in the worst cases, poor reception, rather than constant interference. About eight out of ten VHF problems can be cured by ensuring that the set has good voltage, that the aerial itself is sound and the connections between it and the radio are also sound (soldered plugs for instance rather than loose centre cores as can often be discovered).

It is possible that some very localised source could be bleeding interference across the whole band but everyone else would be getting that too and it should disappear if you leave the immediate area.