Old receiver - preselector/antenna tuner
 

Sounds like a great idea. A lot of people would love to have those
components !



"HankG" wrote in message
...
I have a WWII, tube-type, military receiver which stopped working some
years
back. The radio is built like a tank. It has a large variable cap with a
precise planetary drive (no bandspread). A resistor burned out and I
suspect it needs to be recappled also, which I'm not about to do.

My current radio is an RX-320 which far exceeds what the above radio was
capable of delivering (digital tuning, stable side-band, etc.). I'm using
2
antennas; a folded dipole inside my roof, and a 100+ foot longwire
(outside
on a fence).

The dipole seems to be less sensitive at the lower and upper ends of the
SW
band, which is the area where I use the longwire. I was thinking about
the
possiblilty of using the variable cap/coils as a (non-amplified) antenna
tuner or pre-selector.

Anyone care to comment on this idea? Thanks.

HankG

If you have a good circuit design, of course. There are folks here who can
help you out very much in getting it right.

"Warpcore" wrote in message
ink.net...
If you have a good circuit design, of course. There are folks here who can
help you out very much in getting it right.

Let me clarify things a little. My intent, since the radio is not
functional, was to use the variable cap and associated coils (tank
circuit?), without any power applied. This would be 'the circuit'.
ANTENNATANK CIRCUITRECEIVER. The remainder of the radio would be 'out
of the circuit'.

HankG

Original post: Evaluate using non-functional SW receiver (variable cap and
coils, only) as an antenna tuner or preselector. No amplification.

"HankG" wrote in message
...

"Warpcore" wrote in message
ink.net...
If you have a good circuit design, of course. There are folks here who
can
help you out very much in getting it right.

Let me clarify things a little. My intent, since the radio is not
functional, was to use the variable cap and associated coils (tank
circuit?), without any power applied. This would be 'the circuit'.
ANTENNATANK CIRCUITRECEIVER. The remainder of the radio would be
'out
of the circuit'.

HankG

Which radio do you have? You might get it to work as a preselector by
hooking up the antenna to the mil radio's antenna terminals and taking the
output from the grid connection of the RF amplifier. If the radio uses grid
cap tubes, this would be pretty easy. However, the impedences might be all
wrong. Trying to use the coils and cap as an antenna tuner would involve
butchering the radio, with no guarantee of success. Have you considered
selling the radio and buying an antenna tuner?

Frank Dresser