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Old July 27th 05, 07:02 PM
Mark Zenier
 
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In article ,
David wrote:
On Wed, 27 Jul 2005 03:14:50 GMT, newbieguy
wrote:

When I was a kid, I used to listen to my grandfather's AM tube radio.
It was a breadbox sized Philco, I believe vintage 1940s. It had
excellent reception and excellent sound due to a big old 6x9 inch
speaker on the bottom. I would like to get me a am tube radio. I see
lots on ebay in various conditions, many pretty cheap. But I know
nothing about them, what is good and what is not. Where can I learn
more?

Take plastic knob off the tuner, stand in a puddle, change channels.


The old brown bakelite case with Octal tubes, (RCA, I think), we had in
the kitchen was even better than that. It had a metal set screw on the
volume control. Ouch.

For the OP, there was a low cost design called the "All American 5"
that was the guts to most of the tabletop AM Broadcast band radios
(in North America) from after WW-II through the mid 1960s. It was low
cost because it didn't use a power transformer and the power line was
connected to the chassis. If you had the power plug in the wrong way,
line voltage was present on any metal parts that the user could
accidentally contact.

This is where all the movie scenes came from that show people electrocuted
in the bathtub. It really happened, too. Most radio nuts knew at least
a friend of a friend who got killed. (In my case, a friend of my high
school electronics shop teacher).

Some shortwaves used this design, too. National SW-54, Knight
Star Roamer(?) , Hallicrafters S-38, and the cheapest Heathkit.

And the audio output tube (50C5 or 50L6) was always good for a couple
of burned fingers if you didn't let it cool down before you tried to
take it out of the socket.

A good place to start is to find an affordable copy of the _RCA
Receiving Tube Handbook_.

Mark Zenier
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