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Old 05-09-2012, 01:53 PM   #13
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Join Date: Apr 2004
Location: Ballston Lake, NY
Posts: 767

1999 SW2
Default Re: PCM generated radio noise on 146.520

Originally Posted by kg6mvb View Post
Ouch...bad clock choice.

Along with the other suggestions, here are a few more.

An HT with the antenna removed makes a good signal sniffer. If you have too much signal, try the third harmonic (439.56).

If you can pinpoint a source, try putting a snap on ferrite core(s) over the lines as close to the source as possible. Shielding the lines can't hurt either. Finally experiment with antenna locations. You may not be able to get rid of it, but maybe you can lower the level a bit.

Good luck and 73
Here's what I found. Holding an HT, no antenna, up to the OBD port S9+60, next to the battery leads 0. Have 2 snapon ferrites on all 4 of the pcm harnesses and reduced signal 2 s-units, still not usable. Signal is radiated from the data/clock lines and what makes it worse is I'm using a scanguage and a ultraguage, all plastic and excellent antennas. This is on a SW2 and antenna is on rear of roof fed with double shielded coax. Just a note, there was a posting on one of the ham boards how a fellows wife's S car would stop his scanner turning into the driveway.


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