channel 80 interference

[SteveGorst]

Hi all
I've installed a new SX35 and thought all was working perfectly until I came to using channel 80 one day in Conwy. There is terrible interference on this channel which I can't remove with the squelch. I only have the one radio on the boat at the moment so I'm not sure whether it was an external problem with someone else transmitting interference or whether it was something to do with my setup.

Is it possible for my set up to be misbehaving on channel 80 only?

Cheers
Steve

<hr width=100% size=1><A target="_blank" HREF=http://"www.nwcc.info">North Wales Cruising Club</A>

 

[Nick_Pam]

Possibly, but it is more likely that there is some air-borne interference on the channel emanating locally that you are picking up.
A lot of equipment these days gives out EMI (Electro-Magnetic Interference) It's one of the things that the CE Kite-mark was set up to deal with.
Nick

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[SteveGorst]

Yes I suppose that could be it but i've checked it again and it's still doing it. There is a new marina being built at the moment near our mooring so I wonder if someone has a dodgy power tool. If that was the case though wouldn't it be across more than one channel...

Thanks.
Steve

<hr width=100% size=1><A target="_blank" HREF=http://"www.nwcc.info">North Wales Cruising Club</A>

 

[malcp]

Does the interference still occur when you only have the SX35 on and nothing else? This would indicate if it's interference from another of your on board electronic systems or is external.

I've experienced interence from my echo sounder on some VHF channels much more than others. What is the nature of the interference, is it pulsed, continuous?

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[SteveGorst]

The interference is more or less continuous, just occasional gaps. I haven't tried turning other equipment off. That sounds like a good avenue to explore so I'll try that this weekend.

Cheers
Steve

<hr width=100% size=1><A target="_blank" HREF=http://"www.nwcc.info">North Wales Cruising Club</A>

 

[milltech]

Also good basic fault finding would be to see if any neighbour boats are currently suffering the same way, especially if they had the same radio.

<hr width=100% size=1>John
<A target="_blank" HREF=http://www.allgadgets.co.uk>http://www.allgadgets.co.uk</A>

 

[misterg]

Steve,

We're in moored in the river, and were around Sat p.m for about 5 hours. I'm 99% certain the VHF was on dual watch with CH80 at the time. Everything seemed normal. I've listened out on CH80 a few times out of curiosity (but yet to hear anything interesting!) - no interference, though.

Connections to antenna all ok?

Andy.

(Mobile incompetence display team)

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[SteveGorst]

Thanks for the reply Andy. That seems to eliminate external interference so I'll investigate other sources this weekend. I had wondered about the connection to the aerial but could that cause interference on only one channel?

Steve

<hr width=100% size=1><A target="_blank" HREF=http://"www.nwcc.info">North Wales Cruising Club</A>

 

[robp]

I wonder if it's something to do with the fact that Ch 80 is not a duplex channel? (You can only hear the marina side). If the set is not tuned correctly, there might be interference from an adjacent frequency. That would need a bench set up by engineers I guess.

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[bedouin]

To be accurate - Ch 80 IS a duplex channel - which means that you can only hear one side of the conversation.

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[robp]

Oops - syntax error!

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[misterg]

Regarding 1 channel only, I'm sure there are as many technical arguments as why it could as there are to prove it couldn't.

However - when I was installing my new echo sounder this spring (with the boat ashore, mast down, just a length of aerial lead on the VHF) it caused tremendous interference on certain channels (maybe 3 or 4??), nothing on others. Once mast was up & aerial connected everything was fine. In this case, the interference stopped when the sounder was switched off, or if the aerial lead was unplugged from the radio. (Radio is old, conventional VHF).

May be of limited relevance!

Good luck,

Andy

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[SteveGorst]

Thanks for the reply Andy. I suppose if the interfering equipment is operating at a fixed freqency then the interference it gives off could be of a fixed frequency and so limited to a channel or two. It could be that I need to make sure the wires from other instruments are kept futher away from the VHF aerial. This could obviously be difficult in the case of the anemometer lead!!

This could give me hours of fun this weekend.

Cheers
Steve



<hr width=100% size=1><A target="_blank" HREF=http://"www.nwcc.info">North Wales Cruising Club</A>

 

[steverow]

GPS the most likely culprit, or Echo sounder.
Mine does it too. SX35 seems a bit prone...but otherwise a good radio.

Have a check through the channels and see if any others have interference.
Also worth a check on the Antenna connections and general earthing on the radio.

Steve.


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