Lynn wrote:



Ken's idea of going to class A might work, but the 245 would be running
in a very inefficient mode.


I can't fathom a 20s xmtr circuit running the PA in Class A.

-ex

Lynn wrote:

"Tio Pedro" wrote in message
...

"ken scharf" wrote in message
...
Even with it's 'hard vacuum' the 01 didn't have as good a 'getter'
as later tubes and would arc over with more than 130 volts or so. It
was used as a transmitter before the type 202 tube became widely
available, but was a QRP thing, less than a watt input.

Will it have enough output to drive a 245?
I doubt it very seriously. I suppose if perfection was achieved in matching
the 01's output to the 245's grid was possible (I, for one cannot do it),
the losses would be enough to tickle it into the beginning of class C.

Ken's idea of going to class A might work, but the 245 would be running
in a very inefficient mode. There is one website showing a couple of
45's running in AB2 (how do you make a sub 2?) . Another website
has some interesting stuff with 245 chatter...... (you may have already
seen it, but just in case..........

http://www.antiquewireless.org/otb/29amp.htm

Old Chief Lynn, W7LTQ and a couple commercials
Actually AB1 would be better. My point was that you don't need driving
power until you start drawing grid current. As long as the final
doesn't draw grid current you are not loading down the oscillator tube.
The question was would the 01A be able to drive a '45. My answer is
yes, but probably not to full output....meaning you won't be able to
supply much grid current.

"ken scharf" wrote in message
...
Lynn wrote:

"Tio Pedro" wrote in message
...

"ken scharf" wrote in message
...
Even with it's 'hard vacuum' the 01 didn't have as good a 'getter'
as later tubes and would arc over with more than 130 volts or so. It
was used as a transmitter before the type 202 tube became widely
available, but was a QRP thing, less than a watt input.

Will it have enough output to drive a 245?
I doubt it very seriously. I suppose if perfection was achieved in
matching
the 01's output to the 245's grid was possible (I, for one cannot do it),
the losses would be enough to tickle it into the beginning of class C.

Ken's idea of going to class A might work, but the 245 would be running
in a very inefficient mode. There is one website showing a couple of
45's running in AB2 (how do you make a sub 2?) . Another website
has some interesting stuff with 245 chatter...... (you may have already
seen it, but just in case..........

http://www.antiquewireless.org/otb/29amp.htm

Old Chief Lynn, W7LTQ and a couple commercials
Actually AB1 would be better. My point was that you don't need driving
power until you start drawing grid current. As long as the final doesn't
draw grid current you are not loading down the oscillator tube.
The question was would the 01A be able to drive a '45. My answer is yes,
but probably not to full output....meaning you won't be able to supply
much grid current

Yor're correct (as qualified, and as usual)
But the 01A is NOT a suitable (satisfactory?) driver
for a 45.

Happy New Year! (Will I see any of you on "Straight Key Night?(

Old Chief Lynn

Lynn wrote:

"ken scharf" wrote in message
...
Lynn wrote:

"Tio Pedro" wrote in message
...

"ken scharf" wrote in message
...
Even with it's 'hard vacuum' the 01 didn't have as good a
'getter' as later tubes and would arc over with more than 130 volts
or so. It was used as a transmitter before the type 202 tube
became widely available, but was a QRP thing, less than a watt input.

Will it have enough output to drive a 245?
I doubt it very seriously. I suppose if perfection was achieved in
matching
the 01's output to the 245's grid was possible (I, for one cannot do
it),
the losses would be enough to tickle it into the beginning of class C.

Ken's idea of going to class A might work, but the 245 would be running
in a very inefficient mode. There is one website showing a couple of
45's running in AB2 (how do you make a sub 2?) . Another website
has some interesting stuff with 245 chatter...... (you may have already
seen it, but just in case..........

http://www.antiquewireless.org/otb/29amp.htm

Old Chief Lynn, W7LTQ and a couple commercials
Actually AB1 would be better. My point was that you don't need
driving power until you start drawing grid current. As long as the
final doesn't draw grid current you are not loading down the
oscillator tube.
The question was would the 01A be able to drive a '45. My answer is
yes, but probably not to full output....meaning you won't be able to
supply much grid current

Yor're correct (as qualified, and as usual)
But the 01A is NOT a suitable (satisfactory?) driver
for a 45.

Happy New Year! (Will I see any of you on "Straight Key Night?(

Old Chief Lynn
Well the original question was would it work, and the answer is yes, but
not very well.

If you want to use tubes from the same era, then I'd pick a '27 for the
oscillator. The 27 is probably the first tube in a chain of evolution
that led up to the 1626 which was used for the same purpose in the ARC-5
transmitters. (though the 1625 is a heck of a lot easier to drive than
a '45!).

"ken scharf" wrote in message
...
Lynn wrote:

"ken scharf" wrote in message
...
Lynn wrote:

"Tio Pedro" wrote in message
...

"ken scharf" wrote in message
...
Even with it's 'hard vacuum' the 01 didn't have as good a 'getter'
as later tubes and would arc over with more than 130 volts or so. It
was used as a transmitter before the type 202 tube became widely
available, but was a QRP thing, less than a watt input.

Will it have enough output to drive a 245?
I doubt it very seriously. I suppose if perfection was achieved in
matching
the 01's output to the 245's grid was possible (I, for one cannot do
it),
the losses would be enough to tickle it into the beginning of class C.

Ken's idea of going to class A might work, but the 245 would be running
in a very inefficient mode. There is one website showing a couple of
45's running in AB2 (how do you make a sub 2?) . Another website
has some interesting stuff with 245 chatter...... (you may have already
seen it, but just in case..........

http://www.antiquewireless.org/otb/29amp.htm

Old Chief Lynn, W7LTQ and a couple commercials
Actually AB1 would be better. My point was that you don't need driving
power until you start drawing grid current. As long as the final
doesn't draw grid current you are not loading down the oscillator tube.
The question was would the 01A be able to drive a '45. My answer is
yes, but probably not to full output....meaning you won't be able to
supply much grid current

Yor're correct (as qualified, and as usual)
But the 01A is NOT a suitable (satisfactory?) driver
for a 45.

Happy New Year! (Will I see any of you on "Straight Key Night?(

Old Chief Lynn
Well the original question was would it work, and the answer is yes, but
not very well.

If you want to use tubes from the same era, then I'd pick a '27 for the
oscillator. The 27 is probably the first tube in a chain of evolution
that led up to the 1626 which was used for the same purpose in the ARC-5
transmitters. (though the 1625 is a heck of a lot easier to drive than a
'45!).


Right again, Ken. Those ARC-5's were sure a lot of fun when new ones
were $5 a crack! Used one for VFO on a BC-375 when the'375 was
$45, new, complete with all tuning units, dynamotor, antenna tuner,
antenna switch with RF ammeter, etc! Glory days of radio. If one didn't
mind a little "yoooooop de yoooop yoooop" on CW, the 211 in the
'375 in MOPA mode made a nice oscillator tube as well!

Old Chief Lynn

"ken scharf" wrote in message If you
want to use tubes from the same era, then I'd pick a '27 for the
oscillator. The 27 is probably the first tube in a chain of evolution
that led up to the 1626 which was used for the same purpose in the ARC-5
transmitters. (though the 1625 is a heck of a lot easier to drive than a
'45!).


I agree Ken. A lot of the early 30s rigs used a tetrode driving a 45.
I'll have to dig deeper. (Looking for retirement projects!)
I saw a neat design using a pair of 30s to drive a P-P pair of 33s in
one battery TX QST ran in 32 or so.

Pete

On Dec 30, 2:54*pm, ken scharf wrote:
Tio Pedro wrote:
"ken scharf" wrote in message
...
* Even with it's 'hard vacuum' the 01 didn't have as good a 'getter' as
later tubes and would arc over with more than 130 volts or so. *It was
used as a transmitter before the type 202 tube became widely available,
but was a QRP thing, less than a watt input.

Will it have enough output to drive a 245?

I'm sure it will drive a neutralized 245 to provide some gain.
You might not get enough drive for full power output from the 245.
(even if the 245 was run in class A, which requires NO driving power
you would still see SOME power gain).

Hmmmm...You think class A at RF requires no driving power??

Cheers,
Tom

K7ITM wrote:
On Dec 30, 2:54 pm, ken scharf wrote:
Tio Pedro wrote:
"ken scharf" wrote in message
...
Even with it's 'hard vacuum' the 01 didn't have as good a 'getter' as
later tubes and would arc over with more than 130 volts or so. It was
used as a transmitter before the type 202 tube became widely available,
but was a QRP thing, less than a watt input.
Will it have enough output to drive a 245?
I'm sure it will drive a neutralized 245 to provide some gain.
You might not get enough drive for full power output from the 245.
(even if the 245 was run in class A, which requires NO driving power
you would still see SOME power gain).

Hmmmm...You think class A at RF requires no driving power??

Cheers,
Tom
Only voltage, no current.
Of course some power gets wasted since resistance isn't zero and some
heat is generated in the coils, etc. I guess there is some power factor
in the grid / cathode capacitance etc. The input impedance of the '45
in class A SHOULD BE infinite. It isn't, but it IS VERY HIGH. So
except for losses, no driving power, only voltage.

Tio Pedro wrote:
"ken scharf" wrote in message If you
want to use tubes from the same era, then I'd pick a '27 for the
oscillator. The 27 is probably the first tube in a chain of evolution
that led up to the 1626 which was used for the same purpose in the ARC-5
transmitters. (though the 1625 is a heck of a lot easier to drive than a
'45!).


I agree Ken. A lot of the early 30s rigs used a tetrode driving a 45.
I'll have to dig deeper. (Looking for retirement projects!)
I saw a neat design using a pair of 30s to drive a P-P pair of 33s in
one battery TX QST ran in 32 or so.

Pete


The 27 is an indirectly heated triode.
Except for the Kellog tube, it was the first one ever made.
(not talking prototypes though).

The 24A is a tetrode. Than might make a nice xtal oscillator to drive
the '45.

On Dec 31 2008, 7:16*pm, ken scharf
wrote:
K7ITM wrote:
On Dec 30, 2:54 pm, ken scharf wrote:
Tio Pedro wrote:
"ken scharf" wrote in message
. ..
* Even with it's 'hard vacuum' the 01 didn't have as good a 'getter' as
later tubes and would arc over with more than 130 volts or so. *It was
used as a transmitter before the type 202 tube became widely available,
but was a QRP thing, less than a watt input.
Will it have enough output to drive a 245?
I'm sure it will drive a neutralized 245 to provide some gain.
You might not get enough drive for full power output from the 245.
(even if the 245 was run in class A, which requires NO driving power
you would still see SOME power gain).

Hmmmm...You think class A at RF requires no driving power??

Cheers,
Tom

Only voltage, no current.
Of course some power gets wasted since resistance isn't zero and some
heat is generated in the coils, etc. *I guess there is some power factor
in the grid / cathode capacitance etc. *The input impedance of the '45
in class A SHOULD BE infinite. *It isn't, but it IS VERY HIGH. *So
except for losses, no driving power, only voltage.

OK, to get an _accurate_ answer with respect to grid driving power,
you need to account for the effects of the electrons going from
cathode to plate as they pass by the grid. At high enough frequency,
this becomes significant. This is quite apart from losses in elements
external to the tube. One reference about this is Terman's "Radio
Engineers' Handbook, section 4, paragraph 9. But just consider that
it takes a certain amount of _energy_ to push those electrons around
and control them, even if they don't actually ever come in contact
with the grid.

Cheers,
Tom