"Mark Keith" wrote in message
om...
-

A friend of mine used one of those as his first receiver. This was
back when we were in jr.hi school...We built homebrew 6v6 transmitters
to yik yak on 40m cw. I used to go over and operate on his setup
sometimes...The S-38 had an annoying quirk when working CW...If you
hit the table with your knee, the radio suddenly jumped off down the
band, never to return unless you got lucky... Not the most stable
thing I've ever seen...Many times we would start working people, but
hit the table, and never find them again....

That was probably caused by those goofy cut plates on the bandspread part of
the tuning capacitor. The plates have the profile of the linear frequency
type used on the some of the old TRFs. I have no idea why they used such an
unbalanced plate design for the radio's bandspread. It doesn't even work as
a linear type with all the capacitance of the main tuning cap in parallel.
The tuning rate gets faster as the bandspread cap is closed.


He finally upgraded to
a halliscratchers sx-40, which was fairly decent in comparion. I've
got an old National receiver which is very similar to a S-38 in basic
design and coverage.
But I've never plugged it in to see if it works, even though it's been
sitting here for years...I just keep it around as a decorative room
object. :/
MK

Probably real easy to recap! Not much else goes wrong with these type of
radios.

Frank Dresser

The recap was very easy plently of room to unsolder/solder as
everything was basically on the chassis. I did make one additional
purchase an EICO (remember them?)
Q Multip0-lier that I had my dad help me figure out how to install.
The one thing that I learned to do was replace the dial cords, as they
freyed with heavy use. The stability in AM/CW/SSB left alot to be
desired but its a fun set, the dial had all thode countries printed on
it, but with no particular point to set the dial marker to. The newer
digital rreceivers make tuning a frequency next to impossible to botch
up unless you cant read numbers.

Regards
Chaz

In article ,
(Charlie B.) wrote:

The recap was very easy plently of room to unsolder/solder as
everything was basically on the chassis. I did make one additional
purchase an EICO (remember them?) Q Multip0-lier that I had my dad
help me figure out how to install. The one thing that I learned to do
was replace the dial cords, as they freyed with heavy use. The
stability in AM/CW/SSB left alot to be desired but its a fun set, the
dial had all thode countries printed on it, but with no particular
point to set the dial marker to. The newer digital rreceivers make
tuning a frequency next to impossible to botch up unless you cant
read numbers.

Yes I remember EICO. They made kits and test equipment. My first
oscilloscope as a teenager was an all tube EICO kit. This single
channel baby had a huge 4.5 MHz bandwidth and round electrostaticly
controlled CRT!

--
Telamon
Ventura, California

"Frank Dresser" wrote in message ...
"Mark Keith" wrote in message


Probably real easy to recap! Not much else goes wrong with these type of
radios.

Frank Dresser

Yea, I wouldn't be surprised if it worked. Maybe with a little hummmm
though...
But I never had much use for it, so never have bothered with it. I
sometimes wonder how the MW might be on it, but when you have usual
newer radios, and also a 58 TO, and a big 48 RCA console, it starts to
look a bit lackluster..I notice the chassis will be hot with line
voltage on that old thing...Probably a good subject for a isolation
tranny to make it safe. MK

"Mark Keith" wrote in message
om...

But I never had much use for it, so never have bothered with it. I
sometimes wonder how the MW might be on it, but when you have usual
newer radios, and also a 58 TO, and a big 48 RCA console, it starts to
look a bit lackluster.

It's an "All American Five" with shortwave bands, so it won't be any better
than they were.
http://www.plexoft.com/SBF/mounted/5tube.html

.I notice the chassis will be hot with line
voltage on that old thing...Probably a good subject for a isolation
tranny to make it safe. MK

Excellent idea.

"PM"

"Mark Keith" wrote in message
om...


Yea, I wouldn't be surprised if it worked. Maybe with a little hummmm
though...
But I never had much use for it, so never have bothered with it. I
sometimes wonder how the MW might be on it, but when you have usual
newer radios, and also a 58 TO, and a big 48 RCA console, it starts to
look a bit lackluster..I notice the chassis will be hot with line
voltage on that old thing...Probably a good subject for a isolation
tranny to make it safe. MK


There's an alternative to an isolation tranformer, if you want to save a
little money and space. If the chassis is truely hot, that is with one
conductor of the power cord connected to the chassis and the steel cabinet
isolated on grommets, you can rewire it for a 3 wire cord. Connect the
cord's ground wire to the cabinet, the neutral wire to the chassis and the
hot wire to the switch. A bit of rewiring may be necessary, because these
radios typically connected the hot wire to the B+ rectifier and heater
string and switched the neutral to reduce hum pickup on from the power
switch on the back of the volume control. In practice, it doesn't usually
make much difference in hum if the wires at the switch are hot or neutral.
It's easy to rewire for the three wire cord, and it's almost impossible to
accidently touch anything that's electrically hot. I rewired my S-38 that
way, and it works fine.

Most AC/DC radios from about 1950 or so used a floating ground bus. There
was no direct connection from the power cord to the chassis. This is a
safer design than the true hot chassis, but it can also similarly be rewired
for a theee wire cord, or a polarized two wire cord. Either works, and is a
further safety improvement.

I always like to add a terminal strip and a1/2A pigtail fuse in these
radios, too. The fuse is redundant because there's a pinched down area in
one of the wires inside the rectifier, which serves as the radios fuse.
However, these tubes are getting a little expensive, and I'm convinced the
fuses I've added once saved me a rectifier tube.

I won't recommend this if you don't enjoy doing this kind of work, though.
These kind of radios are decent SWL radios, but nothing special. They do
have decent non-fatigueing audio, and you can listen for hours and only get
annoyed with the programming. Good for a shop radio.

Frank Dresser