Hey, my SX-42 has been fully restored and has the correct speaker as well as
a cabinet. And it has been touched by Phil Nelson :-) Maybe I should put it
on eBay with a BIN price of $2000+ !

http://www.antiqueradio.org/halli07.htm

Phil

On Fri, 24 Oct 2008, Phil Nelson wrote:

Date: Fri, 24 Oct 2008 12:05:04 -0700
From: Phil Nelson
Newsgroups: rec.radio.amateur.boatanchors
Subject: SX-42 for $2250.00 how did I miss it?

Hey, my SX-42 has been fully restored and has the correct speaker as well as
a cabinet. And it has been touched by Phil Nelson :-) Maybe I should put it
on eBay with a BIN price of $2000+ !

http://www.antiqueradio.org/halli07.htm

Phil


At prices like that, I'd seriously consider building reproductions from
new materials and use NOS tubes.

;-)

Can any one explain the rationale behind using both octal and loctal tubes in
the SX-42?

73

Tony I0JX

Antonio Vernucci wrote:
Can any one explain the rationale behind using both octal and loctal tubes in
the SX-42?

Loctal tubes were really cheap on the surplus market at the time?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...
Antonio Vernucci wrote:
Can any one explain the rationale behind using both octal and loctal tubes
in
the SX-42?

Loctal tubes were really cheap on the surplus market at the time?

I believe the lone Loctal tube was a 7F8; at least this the tube used in my
SX-43. If you want to read more about this particular tube, check out the
volume on components from the MIT Radiation Laboratory series. If memory
serves, this dual triode was rated to much higher frequencies than any dual
triode that had an octal base. These tubes are still available NOS.
However, if you are willing to make an adapter or rewire the receiver, I
believe a 12AT7 can be used. Of course, if you want "museum quality", which
I think is rather foolish, use the 7F8.

73, Dr. Barry L. Ornitz WA4VZQ

NoSPAM wrote:
"Scott Dorsey" wrote in message
...
Antonio Vernucci wrote:
Can any one explain the rationale behind using both octal and loctal tubes
in
the SX-42?

Loctal tubes were really cheap on the surplus market at the time?

I believe the lone Loctal tube was a 7F8; at least this the tube used in my
SX-43. If you want to read more about this particular tube, check out the
volume on components from the MIT Radiation Laboratory series. If memory
serves, this dual triode was rated to much higher frequencies than any dual
triode that had an octal base. These tubes are still available NOS.
However, if you are willing to make an adapter or rewire the receiver, I
believe a 12AT7 can be used. Of course, if you want "museum quality", which
I think is rather foolish, use the 7F8.

73, Dr. Barry L. Ornitz WA4VZQ

This is true, it was a very high performance tube. But it's also true that
after the war a lot of equipment came out using surplus loctal tubes; I have
a Philco table radio that is all-loctal.

Incidentally, Barry.... welcome back. I don't think I have seen your name
on Usenet for more than fifteen years and it's great to see you here again.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...
NoSPAM wrote:
"Scott Dorsey" wrote in message
...
Antonio Vernucci wrote:
Can any one explain the rationale behind using both
octal and loctal tubes
in
the SX-42?

Loctal tubes were really cheap on the surplus market at
the time?

I believe the lone Loctal tube was a 7F8; at least this
the tube used in my
SX-43. If you want to read more about this particular
tube, check out the
volume on components from the MIT Radiation Laboratory
series. If memory
serves, this dual triode was rated to much higher
frequencies than any dual
triode that had an octal base. These tubes are still
available NOS.
However, if you are willing to make an adapter or rewire
the receiver, I
believe a 12AT7 can be used. Of course, if you want
"museum quality", which
I think is rather foolish, use the 7F8.

73, Dr. Barry L. Ornitz WA4VZQ

This is true, it was a very high performance tube. But
it's also true that
after the war a lot of equipment came out using surplus
loctal tubes; I have
a Philco table radio that is all-loctal.

Incidentally, Barry.... welcome back. I don't think I
have seen your name
on Usenet for more than fifteen years and it's great to
see you here again.
--scott

I am not quite sure of the origin of the loctal base
but I think it was Philco. At any rate they made and used
them very widely in their radio sets. Philco was a large
supplier of automobile radios, I think for Ford. Loctal
tubes were supposed to be resistant to shaking loose when
subject to vibration.


--

--
Richard Knoppow
Los Angeles
WB6KBL

"Antonio Vernucci" wrote in message
...
Can any one explain the rationale behind using both octal
and loctal tubes in the SX-42?

73

Tony I0JX

Some locktal tubes had quite low interelectrode
capacitance compared to their octal equvalents due to the
stem seal base with shorter leads than octals. They were
also quite rugged since they were originally intended for
automobile receivers and some had less microphonics.
Remember, locktals predated miniature tubes but had some of
the advantages of miniatures due to the method of bringing
the leads out.
Good engineering practice is to use as few variations
of parts as possible but Hallicrafters never seems to have
been concerned with it. I rather think their philosophy was
that people would use a piece of their equipment until the
new model came out. One can find a lot of advanced
technology in Hallicrafters stuff, like the use of acorn
tubes, beam switching tubes, pentode RF power tubes, etc,
but often not applied very well.


--

--
Richard Knoppow
Los Angeles
WB6KBL

On Oct 25, 10:28*am, "Antonio Vernucci" wrote:
Can any one explain the rationale behind using both octal and loctal tubes in
the SX-42?

73

Tony I0JX

I don't think there was an obvious rationale behind some Hallicrafters
tube lineup choices.

The SX-110 was introduced in 1959 and made through the 60's, but was
using metal octal tubes - reminiscent of the 1930's - when the rest of
the world (and other Hallicrafters models) had switched to miniatures.

Tim.