I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front
end tubes with some GaAs semi circuits, done on a pcb board and serves
as a direct replacement for the tubes--except for the need of filament
current, they are "work-a-likes" ... gawd, bet those old boys wish they
would've have had those when they engineered the rigs ... I just love
the look of these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Now, this post might NOT be "right on topic" for antennas, but darn
close, we DO have to consider what our antennas feed, right?

Warm regards,
JS

"John Smith" wrote in message
...
I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front end
tubes with some GaAs semi circuits, done on a pcb board and serves as a
direct replacement for the tubes--except for the need of filament current,
they are "work-a-likes" ... gawd, bet those old boys wish they would've
have had those when they engineered the rigs ... I just love the look of
these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Now, this post might NOT be "right on topic" for antennas, but darn close,
we DO have to consider what our antennas feed, right?

Warm regards,
JS

Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a friend
who wanted them for his S line. They were plug in replacements for the
tubes.

Dale W4OP

Dale Parfitt wrote:
"John Smith" wrote in message
...
I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front end
tubes with some GaAs semi circuits, done on a pcb board and serves as a
direct replacement for the tubes--except for the need of filament current,
they are "work-a-likes" ... gawd, bet those old boys wish they would've
have had those when they engineered the rigs ... I just love the look of
these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Now, this post might NOT be "right on topic" for antennas, but darn close,
we DO have to consider what our antennas feed, right?

Warm regards,
JS

Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a friend
who wanted them for his S line. They were plug in replacements for the
tubes.

Dale W4OP

Wes Hayward had a picture of a KWM-2 partly protruding from a bin
labeled "Old Junk". I believe he included it in his _Solid State Design
for the Radio Amateur_. The explanation is that it had been modified by
replacing well designed, high dynamic range tube circuits with much
poorer solid state circuits by someone who didn't understand the
principles of high dynamic range circuit and receiver design. The result
was a receiver with very poor intercept values and consequent severe
problems with intermod and other spurious responses. The well-meaning
modifier had turned a very good receiver into Old Junk.

Roy Lewallen, W7EL

"Roy Lewallen" wrote in message
...
Dale Parfitt wrote:
"John Smith" wrote in message
...
I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front
end tubes with some GaAs semi circuits, done on a pcb board and serves
as a direct replacement for the tubes--except for the need of filament
current, they are "work-a-likes" ... gawd, bet those old boys wish they
would've have had those when they engineered the rigs ... I just love
the look of these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Now, this post might NOT be "right on topic" for antennas, but darn
close, we DO have to consider what our antennas feed, right?

Warm regards,
JS

Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a
friend who wanted them for his S line. They were plug in replacements for
the tubes.

Dale W4OP

Wes Hayward had a picture of a KWM-2 partly protruding from a bin labeled
"Old Junk". I believe he included it in his _Solid State Design for the
Radio Amateur_. The explanation is that it had been modified by replacing
well designed, high dynamic range tube circuits with much poorer solid
state circuits by someone who didn't understand the principles of high
dynamic range circuit and receiver design. The result was a receiver with
very poor intercept values and consequent severe problems with intermod
and other spurious responses. The well-meaning modifier had turned a very
good receiver into Old Junk.

Roy Lewallen, W7EL

I'm not surprised to hear this Roy. I also believe the tubistors were a
short lived product- sought after by BA collectors.

Dale W4OP

Roy Lewallen wrote:

...
Wes Hayward had a picture of a KWM-2 partly protruding from a bin
labeled "Old Junk". I believe he included it in his _Solid State Design
for the Radio Amateur_. The explanation is that it had been modified by
replacing well designed, high dynamic range tube circuits with much
poorer solid state circuits by someone who didn't understand the
principles of high dynamic range circuit and receiver design. The result
was a receiver with very poor intercept values and consequent severe
problems with intermod and other spurious responses. The well-meaning
modifier had turned a very good receiver into Old Junk.

Roy Lewallen, W7EL

True, I have never seen a fet(s)/MMIC do anything a tube, or a few
tubes, can't do--the solid state devices just do it better ...

Regards,
JS

Dale Parfitt wrote:

...
Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a friend
who wanted them for his S line. They were plug in replacements for the
tubes.

Dale W4OP



Your text brings the old nuvistors back to mind ... hot devices, for
their time. As I remember, whether correctly or not, they were offered
by the tube manufacturers in an attempt to compete with transistors--a
failed attempt ...

Regards,
JS

On Wed, 12 Dec 2007 18:47:42 GMT, Dale Parfitt wrote:

I also believe the tubistors were a
short lived product- sought after by BA collectors.

Dale W4OP

ITYM Nuvistors ?

I have both a 6M and 2M converter made by AMECO that are populated with
Nuvistors. I use them with an NC-303 (have 2 of'em) during periods of
manic nostalgia.

No _there's_ a boat anchor: The NC-303! When I was a much younger man I
could actually lift it up onto the workbench all by myself...

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: http://jonz.net/ng.htm

In message jCU7j.17771$dX.3491@trnddc08, Dale Parfitt
writes

"John Smith" wrote in message
...
I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front end
tubes with some GaAs semi circuits, done on a pcb board and serves as a
direct replacement for the tubes--except for the need of filament current,
they are "work-a-likes" ... gawd, bet those old boys wish they would've
have had those when they engineered the rigs ... I just love the look of
these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Now, this post might NOT be "right on topic" for antennas, but darn close,
we DO have to consider what our antennas feed, right?

Warm regards,
JS

Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a friend
who wanted them for his S line. They were plug in replacements for the
tubes.

I remember them from the 1970's as "Fetrons" Similar devices I think.

I also know from experience it wasn't a good idea to replace the valve
HT rectifier with silicon diodes, without a dropper resistor.

Brian GM4DIJ.
--
Brian Howie

Dale Parfitt wrote:
"John Smith" wrote in message
...
I have gotten back into SWL'ing lately ... (ain't like it used to be
either!)

Got a couple of old Hallicrafter receiver rigs and replaced the front
end tubes with some GaAs semi circuits, done on a pcb board and serves
as a direct replacement for the tubes--except for the need of filament
current, they are "work-a-likes" ... gawd, bet those old boys wish they
would've have had those when they engineered the rigs ... I just love
the look of these old "solid" rigs! (solid as in "weighs a ton!)

I am interested in anyone else who has "tweaked" old rigs with various
"kludges" and gotten good results? Comments? Advise? Construction?
Results? Ideas? Unique construction? Anything? ...

Some years ago, I worked on a project to replace tubes in a receiver with
fetrons. The problem was that the fetron had to be designed for a
particular spot in the radio. For example, we couldn't find a design for a
5763 replacement that would work in any socket in the radio that used a
5763. We had to design a fetron for every circuit use--rf amp with agc, rf
amp without agc, etc. even though the tubes could be taken from stock and
plugged in any hole. In the end, some of the circuits remained with tubes.

You will have a lot of fun doing that conversion, but it will be a lot of
work to get optimum performance.

Hi John,
You might want to post in the boatanchors group or the shortwave group
also.
I well recall collecting "tubistors" at Dayton some years back for a
friend who wanted them for his S line. They were plug in replacements for
the tubes.

Dale W4OP

Wes Hayward had a picture of a KWM-2 partly protruding from a bin labeled
"Old Junk". I believe he included it in his _Solid State Design for the
Radio Amateur_. The explanation is that it had been modified by replacing
well designed, high dynamic range tube circuits with much poorer solid
state circuits by someone who didn't understand the principles of high
dynamic range circuit and receiver design. The result was a receiver with
very poor intercept values and consequent severe problems with intermod
and other spurious responses. The well-meaning modifier had turned a very
good receiver into Old Junk.

Roy Lewallen, W7EL

Thinking back, one seldom heard terms like BDR or IP3 knocked around with
respect to amateur receivers of that day. Sensitivity and selectivity was
about it from an advertising standpoint. Amateurs were so determined to get
hold of the new solid state or hybrid gear, that Collins S lines and Drake 4
lines with better specs than the new gear could be had outrageously cheap.

Dale W4OP