On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

On Wed, 16 Nov 2011, dave wrote:

On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

That simple, since there's only a few tubes.

9v "transistor" batteries in series. It doesn't take that many to get
reasonable B+ and since tubes are low current, it's reasonable.

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. A
loss of gain, but sometimes that was a good thing.

Michael

Michael Black wrote:


Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

Even rarer were tubes that drew almost no current. They used "cold cathodes"
so they did not need expensive (in terms of current and heat dissipation)
filaments and had low plate voltages.

They came out when transistors where just starting out, but rise of
transisitors was so rapid and transistors were so cheap in comparison, that
it was simpler and cheaper to build a 7 or 12 transistor radio than a 5 tube
cold cathode one.

They showed some promise in the missle and space exploration systems of the
time, because transistors could not stand the temperature extremes or
cosmic radiation they would be exposed to. That also did not last long,
as improved "space grade" transistors came out.

What really killed them was NASA's adoption of the new integrated circuits
(which actually pre-date the "space race").

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM
My high blood pressure medicine reduces my midichlorian count. :-(

On Thu, 17 Nov 2011 07:34:03 +0000, Geoffrey S. Mendelson wrote:

Michael Black wrote:


Of course, towards the end of the life of tubes, one could get some
that ran off 12v, intended for use in car radios. Not so useful now
since they were produced in a limited time span as transistors were
taking over, so quantity is relatively limited.

Even rarer were tubes that drew almost no current. They used "cold
cathodes" so they did not need expensive (in terms of current and heat
dissipation) filaments and had low plate voltages.

They came out when transistors where just starting out, but rise of
transisitors was so rapid and transistors were so cheap in comparison,
that it was simpler and cheaper to build a 7 or 12 transistor radio than
a 5 tube cold cathode one.

They showed some promise in the missle and space exploration systems of
the time, because transistors could not stand the temperature extremes
or cosmic radiation they would be exposed to. That also did not last
long, as improved "space grade" transistors came out.

What really killed them was NASA's adoption of the new integrated
circuits (which actually pre-date the "space race").

Cold Cathode tubes were voltage regulators, displays, etc. I have never
seen a cold cathode amplifier.

Between miniature tubes and solid state there were Compactrons, which
were several tube stages in a single envelope.

On 11/17/2011 5:18 AM, dave wrote:
On Thu, 17 Nov 2011 07:34:03 +0000, Geoffrey S. Mendelson wrote:

Michael Black wrote:


Of course, towards the end of the life of tubes, one could get some
that ran off 12v, intended for use in car radios. Not so useful now
since they were produced in a limited time span as transistors were
taking over, so quantity is relatively limited.

Even rarer were tubes that drew almost no current. They used "cold
cathodes" so they did not need expensive (in terms of current and heat
dissipation) filaments and had low plate voltages.

They came out when transistors where just starting out, but rise of
transisitors was so rapid and transistors were so cheap in comparison,
that it was simpler and cheaper to build a 7 or 12 transistor radio than
a 5 tube cold cathode one.

They showed some promise in the missle and space exploration systems of
the time, because transistors could not stand the temperature extremes
or cosmic radiation they would be exposed to. That also did not last
long, as improved "space grade" transistors came out.

What really killed them was NASA's adoption of the new integrated
circuits (which actually pre-date the "space race").

Cold Cathode tubes were voltage regulators, displays, etc. I have never
seen a cold cathode amplifier.

Between miniature tubes and solid state there were Compactrons, which
were several tube stages in a single envelope.

There were tubes which contained a bit of thorium and required minimal
heater current. The slight radioactivity is a no go, as well as the
potential pollution to the environment ...

Regards,
JS

On Nov 17, 5:18*am, dave wrote:
On Thu, 17 Nov 2011 07:34:03 +0000, Geoffrey S. Mendelson wrote:
Michael Black wrote:

Of course, towards the end of the life of tubes, one could get some
that ran off 12v, intended for use in car radios. *Not so useful now
since they were produced in a limited time span as transistors were
taking over, so quantity is relatively limited.

Even rarer were tubes that drew almost no current. They used "cold
cathodes" so they did not need expensive (in terms of current and heat
dissipation) filaments and had low plate voltages.

They came out when transistors where just starting out, but rise of
transisitors was so rapid and transistors were so cheap in comparison,
that it was simpler and cheaper to build a 7 or 12 transistor radio than
a 5 tube cold cathode one.

They showed some promise in the missle and space exploration systems of
the time, because transistors could not stand the temperature extremes
or cosmic radiation they would be exposed to. That also did not last
long, as improved "space grade" transistors came out.

What really killed them was NASA's adoption of the new integrated
circuits (which actually pre-date the "space race").

Cold Cathode tubes were voltage regulators, displays, etc. I have never
seen a cold cathode amplifier.

Between miniature tubes and solid state there were Compactrons, which
were several tube stages in a single envelope.

There was also the 'Nuvistor'
http://en.wikipedia.org/wiki/Nuvistor

On 11/16/2011 11:34 PM, Geoffrey S. Mendelson wrote:
Michael Black wrote:


Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

Even rarer were tubes that drew almost no current. They used "cold cathodes"
so they did not need expensive (in terms of current and heat dissipation)
filaments and had low plate voltages.

They came out when transistors where just starting out, but rise of
transisitors was so rapid and transistors were so cheap in comparison, that
it was simpler and cheaper to build a 7 or 12 transistor radio than a 5 tube
cold cathode one.

They showed some promise in the missle and space exploration systems of the
time, because transistors could not stand the temperature extremes or
cosmic radiation they would be exposed to. That also did not last long,
as improved "space grade" transistors came out.

What really killed them was NASA's adoption of the new integrated circuits
(which actually pre-date the "space race").

Geoff.



Yes, you hit on the real death of tubes right there, the IC or
integrated transistors and our ability to place umpteen millions on a
single chip ...

Regards,
JS

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. *Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. *Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. *A
loss of gain, but sometimes that was a good thing.



The R392 used conventional tubes selected for performance at 24 volt B
+. 24 volts isn't much but is a lot better than 12. The 12 volt tubes
were space chrge affairs and were current hogs and delicate.

On Nov 16, 4:23*pm, Michael Black wrote:
On Wed, 16 Nov 2011, dave wrote:
On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
*wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

That simple, since there's only a few tubes.

9v "transistor" batteries in series. *It doesn't take that many to get
reasonable B+ and since tubes are low current, it's reasonable.

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. *Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. *Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. *A
loss of gain, but sometimes that was a good thing.

* * Michael

In the 19-teens it was common to run triodes with no negative bias,
and very low V_anode, like 20-30v. It worked, and cuts HT battery
cost, but of course distorts the grid signal.


NT

On Nov 25, 6:28*pm, NT wrote:
On Nov 16, 4:23*pm, Michael Black wrote:









On Wed, 16 Nov 2011, dave wrote:
On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
*wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

That simple, since there's only a few tubes.

9v "transistor" batteries in series. *It doesn't take that many to get
reasonable B+ and since tubes are low current, it's reasonable.

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. *Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. *Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. *A
loss of gain, but sometimes that was a good thing.

* * Michael

In the 19-teens it was common to run triodes with no negative bias,
and very low V_anode, like 20-30v. It worked, and cuts HT battery
cost, but of course distorts the grid signal.

NT

Sounded like ****, IOW.

Common tubes usually start working okay at 45 to 90 volts. The R-392
used selected tubes at 24-28 volts, and works okay, but not as well as
if they had had more. Collins S/Line used 150 volt B+ for what that is
worth.