12v power filter needed to remove noise from autocom

[zerocool]

Where could I get one of these on short notice?

BMW, Halfords, Maplin?

Can anybody recommend one?

 

[Rasher]

www.chainspeed.co.uk assuming next day is quick enough, or you can get to South Wales to collect

 

[hatzyian]

Where is the noise coming from?
If from another unit, ie satnav, make sure that both units are from the same power point. I had very loud interference, changed so that both units were from aux plug, and the noise was gone

 

[newboy]

+1 for Sam at Chainspeed - great guy and knows his stuff

 

[sanqhar]

Ground Loop Isolation

I have routed all aux stuff through a fuse panel (see Nippy Normans) so everything shares the same power and earth source. Not had a problem.

Otherwise you need to look for a Ground Loop Isolator. Autocom do their own.

tom

 

[zerocool]

I have routed all aux stuff through a fuse panel (see Nippy Normans) so everything shares the same power and earth source. Not had a problem.

Otherwise you need to look for a Ground Loop Isolator. Autocom do their own.

tom

thanks Tom,

I hadnt read your post in time but did figure out that it may have been a ground loop. The radio to comms lead needed some isolation so a optocoupler for the PTT, and two 1:1 transformers from 2 old modems, a little perf board, some burnt fingers and swearing later and I have a working solution.

Im still suffering from overdeviation, the Autocom is overdriving the audio a little so im going to fit a voltage divider circuit on the mic line to give me some adjustability on the comms cable. I tried adjusting the internal pot in the autocom but I cant seem to get it right.

I rang autocom twice and I'm dissapointed to say they were useless, sold me stuff which didnt help and gave me poor advice. When I have it running perfectly I will take some time to share with them a complaint and the info that they should have given me so they can help any other poor souls suffering from the same problem.