wrote in message
...
All,
After a great many years of poking about, I seem to have
acquired a
Zenith 7S633 tabletop set. It seems to have taken a home
underneath a
Philco 38-10 while I was temporarily distracted by the
animals. In
spite of its age, it is all there and works perfectly.
What should I
expect insofar as performance in SW? I use an indoor
inverted L and an
outdoor long wire won't be available. Should I rely on the
internal
antenna? Were these good performers? I already have fallen
for the
black dial Zenith, so asthetics are beyond question.Any
help or
experience with these beauties would be greatly
appreciated. And
photos are available.
rgds,
Mark S.

I don't have one of these but from its schematic it
should have pretty good HF performance. It has an RF stage
using a 7H7 tube, which is a high gm pentode, somewhat
similar but not identical to the 6SG7 plus Loctal type tubes
have somewhat lower interelectrode capacitances than octal
base tubes, both of which can improve high frequency
performance. The RX goes only to 18mhz and should have good
sensitivity right up to the top.
Unfortunalely the service information on Nostalgia Air
has only schematics for this and the 7S733R (can't see much
difference) with no alignment instructions at all.
As to the antenna, a relatively short indoor antenna
will work on any "short-wave" radio but will not have the
performance of a real antenna. About 15 feet of wire strung
across the room will do but if you want something better you
have to go to an outdoor antenna, in the clear, of the right
length, and as high as you can get it.
Its likely that this RX needs some touching up of its
adjustments, they will have drifted over the years.
--
Richard Knoppow
Los Angeles, CA, USA