Bob wrote:
wrote:
Glad to have helped. As people have helped me over the years,
I try to pass my bits of useful knowledge on to those who can
use them.

Thanks again!

In your discussions with Charles Counselman, has he added anything yet
to his document? He had some blank sections that were to come later,
just wondering if he mentioned anything.

Bob

We covered many topics, but it would be hard to extract anything to
post here.
He does intend to post info on his search antenna. A simple 20 turn
loop wound
on a pill bottle will suffice to get you started.

Is your Email valid? I will ask Charles if it is OK to forward you his
B-field noise
sensing diagram.

Depending on how serious, or demented, you are, you might benifit from
rereading
my prior posts on RF hunts. The 20 turn loop is good for finding noisy
devices. A
smaller loop made from a salvaged 100uH axial ferrite inductor is great
for sniffing
around inside a device to find the exact noise source. I built mine in
a old
Sharpie dry marker case. While I added BNC females connectors to all my
probes
because I was in the process of trading for a spectrum anylzer and
wanted to
be able to use my probes with that test gear, a cheaper and more
effective option for
most people would be to use ~3' of RG174 terminated in the coorect
connector for
your noise sniffing receiver. I choose to use a DX398 because I have
one and becuase
it it reasonbly well shielded and does a good job as a sniffer.

Maybe 99% of devices radiate RFI over a very wide frequency range.
Digital noise
tends to be very broadband. Every so often you will find a device that
produces a
strong signal on a specific frequency and does not radiate general RFI.

One common frequency is 3.58MHz, US color refference burst. I had one
early Apex
DVD that I never could quiten down enough to live with. I suppose I
ought to dig through
my notes and list the more common "CPU' frequencies. As NTSC goes away,
and
TV horizontal moves away from 15.73426KHz, (from a grass valley "NTSC
Studio
Timing:") the harmonics that we are used to at ~15.73KHz increments
will vanish.
ATSC can be a can of snakes. (http://www.atsc.org/standards.html)
Butfrom what I
have seen so far ATSC will bigger VHF/UHF RFI issue.

Plasma big screens have their own nasty noise signature. LCDs are cold
cathode
florescent illumintated and the drive oscillators tend to be in the
35~50KHz range
and are fairly well shielded and (most) don't radiate too badly.Perhaps
the best thing
for modern SWLs is the move from over the air TV to cable and
satellite. Older tube
sets had very poor internal shielding and radiated sweep and color
burst back out
the antenna and that 300 ohm ribbon lead made a pretty effective
antenna.

Good hunting

Terry