Fred Hopengarten wrote:
>
> From:
> Fred Hopengarten, K1VR
> Six Willarch Road * Lincoln, MA 01773-5105 * 617/259-0088
> e-mail: k1vr@juno.com or k1vr@k1vr.jjm.com
> Big antennas, high in the sky, are better than small ones, low.
>
> I threw K7FD's question about getting into the speakers of an Aptiva at
> an RFI engineer for Stratus Computer. He's a friend of K1EA and a friend
> of mine. His reply:
>
> From: Owen Gallagher <oweng@oweng.com>
> To: k1vr@juno.com (Fred Hopengarten)
> Subject: Re: k7fd@netbridge.net (John Nicholson): "Contester" interferes
> w/ pc: Help!
>
> Does it have "ce" mark on it? That means it was tested to 3 volts per
> meter.
>
> Try line filter for 3 a 120 vac on each speaker lead grounded to chassis
> and
> same on modem tel line also grounded to chassis.
>
> I know it sounds strange, but power line filters make good audio and
> telcom
> line filters. Cheap and readily available at hamfests.
>
> Also, use a line filter on the power line, grounded to chassis. This is 4
> line
> filters screewed to the chassis.
>
> At 21:00 12/02/1997 EST, you wrote:
> >Owen:
> >
> > Not all RFI problems are all bad.
> >
> >Fred Hopengarten, K1VR
>
> >--------- Begin forwarded message ----------
> >From: k7fd@netbridge.net (John Nicholson)
> >To: CQ-Contest@tgv.com
> >Subject: "Contester" interferes w/ pc: Help!
> >
> >I know there may be better places to post this, but the smartest
> >hams hang out on this reflector & I need advice, so here goes:
> >
> >My neighbor 300' away had an Aptiva 120MHz pentium. No matter
> >what I did, I still got into her computer speakers. Being a good
> >ham (let's pretend I didn't notice her long blonde hair, ok?) I
> >offered to come up with a solution. With that in mind,
> >I put .01 caps on the speaker leads, wrapped the speaker
> >leads around RF choke torroids, and put a brute force telephone
> >filter on her modem. But the speakers STILL picked up my ssb and cw
> >(I run 200w out...3 el Quad up 60'). I even switched out speakers
> >and have had the same problems. The good news is...
> >
> >...in the meantime, she fell in love with me, moved in, learned the
> >code, is taking her Tech Plus this weekend...and we are getting
> >married in July!...
> >
> >...but he bad news is I still haven't found a solution to the Aptiva!
> >Does anyone have any experience with this pc...and what I can do next?
> >As you can see, I'll go to any extent to get this problem solved... :)
> >
> >
> >John K7FD and Annette (KC7U??)
> >
> >
> >--------- End forwarded message ----------
> >
> >
> Owen Gallagher
> Postal Escargot: Internet: Phone + Fax:
> 21 Richardson Rd. oweng@oweng.com +(1) +(508) 568 0320
> Hudson, MA 01749 199.232.57.34
> USA http:/www.ultranet.com/~oweng
Fred, I didn't see the original post, but here is a solution that worked
for me. I added three snap-on ferrite chokes (Radio Shack part #
273-105; $4.99 each, ouch!) on each speaker lead, at the speaker. That
made my 10M SSB negligible at each speaker. This problem was on my
neighbor's PC, located in his house about 200 feet from the tower.
I think if he added another one to each speaker, he couldn't hear it at
all.
Bill, N3RR
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