are: channels 2-6 and channels 7-13
— the length of the downlead isn't
critical. If you decide to put it in
your attic, I suggest using PVC water
pipe as a form for holding the shape
of the antenna. The pipe will also
let you rotate the antenna for
maximum signal strength.
Whether you use the house
wiring or twin-lead dipole, I'm
assuming you don't live in a building
with concrete walls or a metal
skeleton (many commercial buildings
and an increasing number of
residential structures use galvanized
steel studs rather than wooden
two-by-fours). If you live in a building
with metal in the wall, only an
outdoor antenna will work.
WARNING: Under no circumstances should you attempt to
directly connect the household
electric wiring to the antenna
terminals of a TV or VCR. If you do,
you risk damage to the equipment,
fire, and/or electrical shock.
Moreover, the software isn't limited to troubleshooting and repair. PC
users can use it, too, to fine tune their
Reader feedback: Thanks! This
is perfect. It works perfectly on an old
notebook PC I had laying around,
making it a portable test instrument.
Regarding the "Subwoofer Filter"
circuit in the September 2003 issue,
thanks very much. It was exactly
what I was looking for. I look forward
to reading your column every month.
Q. I'm looking forward to retiring
and would like to spend my time
fixing things like PC monitors. To get
a raster, though, you have to hook it
up to a computer. Is there something
that you can plug the monitor into to
test it, other than the computer? Can
it be made?
A. I guess I could design a circuit
for you, but it would require a
signal generator, power supply, and
Even then, all you're going to get
is a raster. What I recommend is
obtaining an old PC — even a 286 will
work (you can buy them every day on
eBay for a song) — then get a copy of
DisplayMate software (www.
DisplayMate not only provides a
raster, but also gives you test patterns
that actually troubleshoot the
Circle #152 on the Reader Service Card.