On Wed, Aug 05, 2009 at 09:02:58AM -0400, Flying Pig wrote: > The standard solution to this involves chokes (ferrites) on every piece of > antenna and power to all electronics, and copper screening around the > entirety of the reefer compressor. Having a direct connection to the > battery for the reefer also sometimes helps...
To follow up on that, minimum-length, extra-heavy power wiring to both the reefer and the SSB are critical (don't forget to check those connections, either!) Many times, that's all it takes to get rid of interference problems. Since the interference is across the band, by the way, I strongly suspect that it _is_ power-based. The ferrite chokes do no harm, but I've rarely seen them do much good where there was a lot of interference. They seem to be most helpful for a low-frequency (AC) hum; "chirping" doesn't sound like it would be affected much, although you might cut out some of the low-freq effects. If you were going to use a choke, I'd certainly add a couple of capacitors - say, a 1μF tantalum and a .001μF ceramic - in parallel with it, just to catch all the stray high-freq stuff too. I've never seen any measurable effect from a home-built copper screen around an appliance. I'm not saying that it's not possible - Faraday cages are indeed a useful tool for, say, a radio-silent testing room - but it takes a good bit more than the average amateur can lash up, especially in the confines of a boat. One solution that I have seen work quite well is having the SSB on a separate battery circuit from the fridge. The people whose boat this was on got tired of interference problems, paralelled another battery into the circuit for charging, and cut it out of the circuit when they wanted to use the radio. No muss, no fuss, no greasy aftertaste; worked great. -- * Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET * _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
