Low plate resistance swamps the capacity ;o)
73, Dave, N3HE

"Highland Ham" wrote in message
...
SNIP=================================
Considering that with so many valves (tubes) in parallel operation the
inter-electrode capacitance is multipled accordingly, it would be
intriguing
to know up to which frequency this set-up could be sensibly used.

I have quite a number of 'never used' 807s in the junkbox , pardon me
........NOS box.
SNIP

"David J Windisch" wrote in message ...
Low plate resistance swamps the capacity ;o)
73, Dave, N3HE

"Highland Ham" wrote in message
...
SNIP=================================
Considering that with so many valves (tubes) in parallel operation the
inter-electrode capacitance is multipled accordingly, it would be
intriguing
to know up to which frequency this set-up could be sensibly used.

I have quite a number of 'never used' 807s in the junkbox , pardon me
........NOS box.
SNIP

OK, we are all agreed - EVEYONE has heaps of 807's in the junkbox for
the "one day" project.......
73 de VK3BFA Andrew

This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for Admiral TVs
years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

Fella used to sell 'em in some of the mid-west hamfests, but I haven't seen
him for a while. Think his name is Don, and that he was also in to Racal
receivers.

73, Dave, N3HE

"Andrew VK3BFA" wrote in message
om...
SNIP
OK, we are all agreed - EVEYONE has heaps of 807's in the junkbox for
the "one day" project.......
73 de VK3BFA Andrew

"David J Windisch" wrote in message ...
This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for Admiral TVs
years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

So what kind of base does your mystery tube have?

"David J Windisch" wrote in message ...
This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for
Admiral TVs
years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

So what kind of base does your mystery tube have?

Ah, nevermind. I see now that the "it" in your question is not the
6MJ6, but your mystery tube...

On 19 Jul 2004 15:38:46 -0700, (Mike Silva)
wrote:

"David J Windisch" wrote in message ...
This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for
Admiral TVs
years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

So what kind of base does your mystery tube have?

Ah, nevermind. I see now that the "it" in your question is not the
6MJ6, but your mystery tube...

perhaps it is just a silly request when he has nothing else to talk
about, it might be 6JS6, 6KD6, or perhaps it was 6JM6.... and
6JM6 GE Vacuum Radio Tubes is offered on internet and the
Current Price: $0.99

so, when 100 persons have commented, it might be a better idea to read
the type number on the glass again and tell us which type the question
was about???


http://home.online.no/~la8ak/e81.htm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

The point is, that I don't know what the nomenclature is, and asked for help
with it in the OP.

"Someone" mentioned this tube in a post "somewhere" several years ago. I've
searched archives for faulty-memory-recollections of the nomenclature, to no
avail.

For latecomer Noeding: I'd like to get enough of them to experiment with
no-tune techniques, which might be practical with plate voltage around 600
and plate current of 4 or 5 amps. The "hilarious" comment referred to plain
old thread-wander ;o)

73, Dave, N3HE

"J M Noeding" wrote in message
...
On 19 Jul 2004 15:38:46 -0700, (Mike Silva)
wrote:

"David J Windisch" wrote in message
...
This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for
Admiral TVs
years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

So what kind of base does your mystery tube have?

Ah, nevermind. I see now that the "it" in your question is not the
6MJ6, but your mystery tube...

perhaps it is just a silly request when he has nothing else to talk
about, it might be 6JS6, 6KD6, or perhaps it was 6JM6.... and
6JM6 GE Vacuum Radio Tubes is offered on internet and the
Current Price: $0.99

so, when 100 persons have commented, it might be a better idea to read
the type number on the glass again and tell us which type the question
was about???


http://home.online.no/~la8ak/e81.htm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

On Tue, 20 Jul 2004 somebody from "over there" wrote:


"Someone" mentioned this tube in a post "somewhere" several years ago. I've
searched archives for faulty-memory-recollections of the nomenclature, to no
avail.

It might have been a hoax, or perhaps problem with memory - not the
eyes......


For latecomer Noeding: I'd like to get enough of them to experiment with
no-tune techniques, which might be practical with plate voltage around 600
and plate current of 4 or 5 amps. The "hilarious" comment referred to plain
old thread-wander ;o)


Well, I'd still endorse the idea of using 807, it is not so many other
6.3V tubes with the same socket, so you are more certain which type
goes there, and not at least - it was once mentioned water-cooling
(QST 1951??) - probably a good idea for those of you who like to tune
for very long periods to get the last microwatt into the antenna

73, jm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm

David J Windisch wrote:

The point is, that I don't know what the nomenclature is, and asked for help
with it in the OP.

"Someone" mentioned this tube in a post "somewhere" several years ago. I've
searched archives for faulty-memory-recollections of the nomenclature, to no
avail.

For latecomer Noeding: I'd like to get enough of them to experiment with
no-tune techniques, which might be practical with plate voltage around 600
and plate current of 4 or 5 amps. The "hilarious" comment referred to plain
old thread-wander ;o)

73, Dave, N3HE

"J M Noeding" wrote in message
...

On 19 Jul 2004 15:38:46 -0700, (Mike Silva)
wrote:


"David J Windisch" wrote in message

...

This is hilarious. The OP asked a question. And asks it again:

What's the nomenclature for that sweep tube, produced just for

Admiral TVs

years ago, that's heavier-duty than any of the other tubes?

I thought it was 6MJ6 -- but, no. It has an *octal* base.

So what kind of base does your mystery tube have?

Ah, nevermind. I see now that the "it" in your question is not the
6MJ6, but your mystery tube...

perhaps it is just a silly request when he has nothing else to talk
about, it might be 6JS6, 6KD6, or perhaps it was 6JM6.... and
6JM6 GE Vacuum Radio Tubes is offered on internet and the
Current Price: $0.99

so, when 100 persons have commented, it might be a better idea to read
the type number on the glass again and tell us which type the question
was about???


http://home.online.no/~la8ak/e81.htm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm



It may be best to pick the least expensive "big" sweep tube for which
you have specs, and parallel enough of them to get the impedance where
you want it to be.

You should also be able to run the voltage down a bit at the tube's
rated current. This will reduce your power output but it'll reduce your
impedance at the same time.

If you use a 3:1 step-down on your output you'll load the plate with 450
ohms. This will require a 1.3A peak current with a 600V plate supply,
and should be good for 300W or more PEP output -- may be easier to start
there than at 5A!

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Tue, 20 Jul 2004 08:56:15 -0700, Tim Wescott
wrote:


It may be best to pick the least expensive "big" sweep tube for which
you have specs, and parallel enough of them to get the impedance where
you want it to be.

You should also be able to run the voltage down a bit at the tube's
rated current. This will reduce your power output but it'll reduce your
impedance at the same time.

If you use a 3:1 step-down on your output you'll load the plate with 450
ohms. This will require a 1.3A peak current with a 600V plate supply,
and should be good for 300W or more PEP output -- may be easier to start
there than at 5A!

of course, but still the impedance from each tube is high, and it does
not see 50 ohm or whatever load, and still you may need an antenna
tuner.

But I was pulling the leg, since it is not a problem for any moderate
intelligent ham to tune a transmitter. Since I am electronic engineer
and have been working with transmitters it amuses me to see that
colleagues don't understand about PLATE and LOAD, and have really
difficulties to tune a transmitter, other radio amateurs have
commented about the same. It is odd that you need to be an amateur to
understand how to tune a transmitter, and I have never seen it as a
problem, even when I started with a Starflite TX 38 years ago

73, jm
---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm