On Sun, 25 May 1997 21:52:07 -0500 Phil Clements <philk5pc@connect.net>
writes:
>At 09:41 PM 5/25/97 EDT, you wrote:
>
>I physically observed the "new" 8K's being assembled at the factory.
>The "stability problem" was mechanical. The alignment of the contacts
>on the solenoids that select the doorknob tuning and loading caps kept
>changing, crispy-crittering and welding them. Also, the Q was very
>high
>in the tank circuit on 15-10 meters due to the inter electrode/socket
>capacitance...over 50 pf. Even with no C1 on these bands in the Pi-L,
>this was far too high. Henry designed a new socket for the tube,
>cutting
>total stray capacitance to around 35 pf,
Very good info Phil. Is the "old" Henry socket the same one that is sold
by RF Parts?
Or do you have any comments about that socket assembly? I have one here
and altho the quality looks good, I question the RF performance along
with the metal chimney.
which is passable for "C1" on
>10m. Too bad, they don't make a manual model of the 8K tailored after
>the 4K. IMO the Henry 4K is probably the best box to ever come out of
>L.A.!
That chrome plated inductor sounds like a great idea, altho a mite
expensive for the homebrewer. I also wonder if the chrome is plated over
nickel? It has been many years since I got a car bumper replated but
seem to remember that the layers were steel, copper, nickel and then the
chrome...damn expensive anyway!
Anyway I am pleased to hear that someone else believes in the resistive
material idea. I get tired of reading "black box" mumbo jumbo and refusal
to admit that the actual DC (or 60Hz AC) thru VHF resistance of the
suppressor inductor plays an important part.
Rp, Zp, Rs, and blah blah is all fine in theory but does not cut it in
actual application where loss is of prime importance to De-Q the circuit.
73....Carl KM1H
>
>(((73)))
>Phil, K5PC
>
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>
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