Forget about the split-clamp ferrites. Opt for the donut style torroid with
a hole big enough to feed the fone line and connector and wrap at least 4
turns. This kept my 56k modem from hanging up when I was on 80 meters.

RF interactions are a fact of life and you need to know how to deal with it.
Most are easily overcome, except for the irate person who would rather be
irate than face it.

ac6tk

http://tekstuff.freespaces.com

"Chuck Harris" wrote in message
...
gil wrote:
Are tube rigs more prone to giving RFI than newer solid state rigs?

An example, an older Heathkit SB 101 vs an Icom 735, both at 50 watts,
same antenna and ground, which one would be most likely to create more
problems with phone, TV etc ??

Gil


If the phone gets bothered, it is broken. If your CD player/record
player/cassette deck/stereo get bothered, they are also broken. Your VCR
was born broken, as its tape stores frequencies from DC thru the 80m.
Any of the above devices will be affected equally by either rig.

As to interferrence with devices that are intended to be receivers,
the Icom will likely be the worse offender. First, it is broadband
in its drivers and finals, so it will be producing lowel levels of
white noise over a significant bandwidth. Second, it is synthesized,
so it will be making a fair bit of phase noise. And third, it is
digital, so there will be some switching noise too. I find that it is
miserable to work on the same band with a modern SS transceiver in
the very near vicinity (same shack, next door, Field Day..). But the
new ones are much better than they once were.

The tube rig has very sharp tank circuits that resonate each stage
on the frequency being transmitted. It has a PI type loading network
that helps with antenna matching, and acts as an additional filter.
The tube rig will likely emit harmonics of the desired frequency, so
you can expect some interferrence that way. And the tube rig will
have some interesting frequencies that result from the internal
mixing schemes that will produce some hot spots.

All-in-all, it doesn't much matter. Big RF will crunch most
consumer electronics, thanks to the FCC sell out that allowed the
manufacturers to leave the RF filtering off, and only add it back
if the owner can figure out who to ask for it.

-Chuck