[R-390] More dweedle-dweedle

[Roger L Ruszkowski]

Hi all,

Confirm that a flat panel monitor is the way to go.  I just had S9+
spikes every 60kHz until I got mine (an el cheapo 12" monitor made in
Taiwan costing around $400 a few years ago.).  I did some tests on
conventional monitors using a scanner and found that there are quite a
few that also have acceptably low levels of RF. Also found my firm's
Dell laptop puts out a lot of sharsh. The R390-A seems to be much less
affected  by computer noise than other radios (A result of the balanced
input ?).

- Bryce
-------------------------
Fellows,

Back before Christmas I was crying about the computer and noise in the RF.
One of the fine fellows here suggested I take the balanced shielded antenna
input
all the way out side to the antenna and not use an un balanced coax line in
the shack.

It was suggested that some CAT 5 line (balanced twisted shielded pairs) be
used.

As life would have it, when I went shopping I found a 100 ft of twin ax at
30 cents a foot
which was cheaper than the cat 5 cable.

Once I put the twinax connector on the coax and got the other end of that
antenna cable
out the door of the shack away from the computer, all the computer crud
dropped several
orders of magnitude. Out side the coax shield is bonded to the ground rod.
I have one
conductor grounded there (a CAP did not act different than a hard DC
ground) and the other
goes to 60 feet of wire up 20 feet in the air. What a change in signals
getting the balanced
shielded line carried far enough away from the computer hash.

I now have a good computer case and power supply. I went through several to
find
a good one that did not make noise. My monitor is kind of OK. Again I have
been through
several to find a quiet one.  My Kamtronix is also a noise source. I had to
install a good
shielded cable between the computer and the Kam with metal back shells and
good
ground bounds all the way through the cable.

Roger KC6TRU.