The30L-1 811A holes were dime size and I wish I knew then what I know now
because I would have made some comparisons. I would have set the drive to
get the tubes red hot on my antenna with SWR 20 and then using same drive
and Ip see what happened loading into a 50 ohm dummy and running. Perhaps
someone has done this and can report the results.
tnx

--
73
Hank WD5JFR
"Richard Clark" wrote in message
...
On Tue, 25 May 2004 19:43:42 GMT, "Henry Kolesnik"
wrote:

Good points, my 30S-1 has load and tune still in it and the final a
3CX1500B is ceramic and can't be seen but it never lost it's Eimac
stencil.
However my Collins 30L-1 was a different story. Once or twice I had
811As
with holes melted in their plate structure. They continued to work well
and
I always thought this was from overdriving but now I'm not so sure
because
it ran at the same high swr as the 30S-1. I used the 30L-1 in summer
because the air conditioner couldn't keep up with the heat generated by
the
30S-1 so it was my winter amp.
I notice that Walt Maxwell's Reflections II was published by World Radio
whereas Reflections was by the ARRL. There is some disagreement on
"conjugate match' and probably other things between ARRL and Walt. So
now I
have to wonder if the final tube is dissipative or non-dissipative for
reflections.

Looks like my new thread isn't working but I'm posting this to it just in
case since I don't really know the customary protocol on a long thread
that
sometime digresses.


Hi Hank,

Those pinholes (or larger) that you found in the plates occurred by a
very fascinating display of plasma. If you are really putting the
hurts to it, you will observe a football shaped plasma between the
plate and the cathode where the point terminates (and penetrates) in
the enlarging ruby glow of the plate. This is visible in some tubes,
not others, depending of course on tube structure. I've had students
point out tubes still operating with the glass envelope completely
melted (or jelled rather) and collapsed, hugging the structure!

Hence you have confirmed the dissipation of return power directly -
all mumbling aside from theorists who describe it as virtual. ;-)

As for Walt's publishing house shift, I don't recall him having any
technical issue, but I let that go as he found another outlet and got
to say what he considered was important. I proofed a number of his
appendices and we corresponded quite often about our differences. To
his credit, although I dispute his stand, he maintains an open mind on
the subject and offers he will look into my experiments that reveal
this. He has already measured the value of 50 Ohms, the point of
departure between us is whether this same value absorbs power.

So, you see, you get numbers from those that sit down to the bench and
do it, you get pixie dust from the rest.

And as for new thread or old, this topic has run to 600+ postings in
years past; so opening it as a new topic is fine to allow news readers
(like mine) from pushing the indentations out to the event horizon.
This post is not so deeply nested though.

73's
Richard Clark, KB7QHC