[RFI] telephone rfi tidbits
David O Hachadorian
Sat, 10 Nov 2001 18:41:06 +0000
I had a neighbor complain of telephone rfi during a contest
last weekend. My XYL took the usual step of handing out
a Radioshack 43-591 phone, but for the first time ever, it
didn't solve the problem.
I got around to working with the neighbor yesterday,
and, to make a long story short, the problem turned out to be
her RCA Directv Satellite Receiver, which is always connected
to the phone line. The receiver modem was actually rectifying the
20 meter RF and putting an extremely loud crackling noise, which
didn't sound at all like the SSB test signal, onto her telephone
line, wiping out all her phones and computer.
I put a Radioshack telephone interference filter on the
satellite receiver, and the problem was solved.
Incidentally, Radioshack has lowered the price on these filters
to $10.99 in their 2002 catalog. The filter attenuation curve
and general appearance is identical to the K-Com unit, which
sells for $16.95 plus shipping.
In conducting the test, the XYL and I communicated
using little Motorola Family Radio units that are available from
Wal-Mart for $32 a pair. They worked great, and didn't experience any
QRM from the 1500 watt transmitter. I just told the xyl when to
transmit, and she pressed the play button on the voicekeyer.
Dave Hachadorian, K6LL