( 94. 3 MHz on Channel 60, etc.). I’ll
probably have to go “off the shelf” to
keep it simple for staff to assemble.
I’m told that RCA makes an AV
accessory box for connecting AV
inputs to TVs that only have a coaxial
input. These boxes supposedly have
an output signal tuneable to most
UHF channels. I’ll connect an audio
cable from a radio tuner to the AV
input on this box. But I believe the
boxes may not have a cable input.
How can I combine the AV box output
with the existing cable-ready feed?
Can I use a CATV splitter in reverse?
Could I use one of those adapters for
adding an in-line UHF antenna?
I know that an electrical hobbyist
could easily connect a transistor radio
to an RF modulator to do what I want,
but designing that circuit is beyond
my skill level. If someone could send
me a circuit diagram, I might be able
to convince staff to let me assemble
it on a breadboard (no soldering
irons in here!). Any help would
be appreciated. You may write to me
Canon City, CO 81215-0777
#07056 Sam Graumann
Canon City, CO
[#1054 - January 2005]
Need a lens to convert a
common PC board camera into a
microscope with magnification
between 60 and 150X.
Circle #51 on the Reader Service Card.
I needed something like this also
and found it much cheaper to
purchase an Intel Play QX3 USB
Microscope. It offers magnifications
of 10, 60, and 200x. The best place to
find one of these today is to look on
eBay where they have been selling in
the $10.00 to $20.00 area. A recent
search showed 28 that sold for less
than $20.00 and 17 that sold for less
than $10.00!!! Many of them were
sold new, still in the sealed box. I have
had very good luck with the one I
purchased for $10.00.
K3PGP - John
[#05051 - May 2005]
I have stereo amps — Fisher, H.
H. Scott, and RCA — that use output
tubes ( 6.6-V, 6BQ5, 9199, etc.) that
are no longer available. I would like
to use transistors instead of tubes
NUTS & VOLTS
#1 First, large vacuum tubes are
not extinct. There is an ad in this
magazine ( www.surplussales.com)
that boasts, "over 1,000,000 tubes in
stock." Antique Electronic Supply at
www.tubesandmore.com is a place
I can recommend. A simple web
search for "vacuum tube" comes up
with a couple of million results
including an easy dozen commercial
vendors. Another route is to search