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Unusual clicking sound

Posted: Thu Feb 14, 2013 4:38 pm
by interference
Hi all,
Can anyone recognise this clicking sound coming through on VHF Hi Band? It comes through as 5 groups of 4 clicks followed by 1 click by itself, then repeats again. Ignore the line hum in the background. This doesn't come through the receiver, it was part of the final recording.
http://chirb.it/fPmNhK

Any suggestions if it is Amateur, telementry, switching, relay, gps, marine related, data etc?

Thanks

Re: Unusual clicking sound

Posted: Thu Feb 14, 2013 6:04 pm
by robbage
My first thought is a spark gap noise such as a relay contact switching. Unusual pattern though. Have you tried a different location (eg walk to the other end of your street)? Never heard that one with amateur, gps, aeronautical or marine.

Re: Unusual clicking sound

Posted: Thu Feb 14, 2013 6:29 pm
by interference
G'day, it can be heard for about a 8 square km area.

Re: Unusual clicking sound

Posted: Fri Feb 15, 2013 3:09 am
by Blinky
Is it on all frequencies in VHF Hi band or spot frequency and can you say which suburb, then if someone is driving by they can have a listen and see if they hear it and perhaps if have a sig strength meter can see where it is strongest. Good foxhunt practice considering it could be restarting sometime although clicks could make it difficult.

:wink:

Re: Unusual clicking sound

Posted: Fri Feb 15, 2013 6:02 am
by robbage
interference wrote:G'day, it can be heard for about a 8 square km area.
Unlikely to be a relay at that range.

Re: Unusual clicking sound

Posted: Mon Dec 30, 2013 4:37 pm
by interference
Hi all,
The interference has been limited over winter but Summer has started it up heavier than usual. It occurs mainly at night so I think it is VHF ducting bringing it from a distance, maybe North of Ocean Reef. It is blocking 156.675 MHz regularly so if anyone is cruising along the coast North of Perth between Ocean Reef and Jurien Bay please feel free to scan around the 156 MHz area and see if you can "Fox Hunt" the location of the transmission if possible. Any help would be appreciated.
Here is a clearer piece of audio of the interference.

http://chirb.it/vqrEw6

Thanks