>On Tue, 17 Mar 98 11:14:14 -0800 Rich Measures <firstname.lastname@example.org> writes:
>>I rarely see a tube with bent filament helixes that exhibits gas
>.........what does that have to do with the single brand new
>tube that you started this discussion with.
Because the tube does not appear to have a gas problem and it
>I sure hate drifty conversations.
You have not explained the mechanism that caused the grid choke to blow,
You have not explained the mechanism that caused the filament helixes to
>>>>By what mechanism does an allegedly defective tube damage the
>>>>parasitic suppressor R and blow the grid choke?
>>>A big bang in an amp without a HV surge resistor.
>>A "big bang" undoubtedly involves some sort of positive hv arc to
>>ground. The path to the chassis can not be through the grid because
>>grid is already connected to the chassis. . How can such an
>>possibly damage the VHF suppressor R, which is paralleled by typically
>>less than 0.001 ohm of copper wire?
>I guess that your version of a failure path and mine differ a lot. The
>DC and the RF enhanced gas paths do differ.
The explanations, please?
>Something I learned as a kid....the path of least resistance....but at age 15
I thought that
seems sorta drifty
>>What is "real proof". Tom Rauch suggested that I faked the
>>photographs of the parasite-toasted bandswitches.
>Who cares what Rauch thinks?
>He may be right or wrong...his opinion is as meaningless as yours without
>proof. "Reportedly" dont mean squat.
Is "squat" a euphemism for "shit", Carl? . . A friend ran the
aforementioned test at his place of employment. If I ran the test
myself, you could claim that I faked the results.
>>>Until that occurs I find it a real stretch to believe that a brand
>>>new 9 year old amp and tubes would harbor a dreaded parasitic at turn-on.
>>- Perhaps it's not all that stretchy. During Final Test, a
>>well-used pair of tubes are typically plugged in whilst the frisky Eimac
>>beauties remain safely tucked away in their factory-sealed boxes. . Should
>>one expect that tired old tubes have as much gain as new tubes? . .
>Maybe in your version of reality. In the real world amps are final
>tested AND shipped with the same tubes.
The 3-500Zs with the TL-922 were in unopened Eimac boxes.
>> I have a tube that was mfg. in 1967, which still works, upon which I
>>will confidently wager a large pizza with 4 toppings and salad bar, that it
>>won't oscillate. .
>A tube....6L6 or what?? I have been thru scores of 3-500Z amps that seem
>to run forever with the original 196x-7x era tubes. It is the later Eimac
>years that fuel the fire....
Thousands of 3-500Zs reportedly filament/grid shorted in early production
SB220s. As I recall, the SB-220 was introduced c. 1969.
R. L. Measures, 805-386-3734, AG6K
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