Eric -- You need to quote back the lines which you are responding to.
Fairure to do so on a discussion group is not considered to be very
Magnificent.
>I just tried to locate an official data sheet for this tube, but I could not
>find one anywhere. However, my Radio Amateur's Handbook lists this tube as
>having an 'operating range' of 110MHZ, which I assume they took from some
>mfrs. data sheet.
Correct. The spec sheets say full ratings to 110MHz for oscillator and
amplifier service.
If you want a spec sheet I can scan one and send it via e-mail.
>Are you claiming that they sell this tube to the user with full knowledge
>that it possesses a very harmful resonance WITHIN its specified operating
>range?
I have no knowledge of what they know about grid resonance. However,
every grid in this universe has c. 10nH per inch of total conductor
length, and some capacitance to the other elements - which together
exhibit a L/C resonant frequency. Below this resonant frequency, a
grounded grid acts as an effective shield between the output and the
input of the amplifier . Above the resonant frequency, the grid looks
more and more like an inductor. At some point, oscillation may be
possible due to the extant feedback C - which, for a 3-500Z is c. 0.15pF.
- Eimac's W. B. Foote told me that their job is to design and produce
tubes. He said that stability is the job of the engineer who designs
amplifiers.
-- Murphy was right -- "Nothing is as simple as it first looks".
>Like if FORD sold you an car knowing full well that it possessed an
>(undamped) front end resonance that would be excited at 70MPH?
So far, Ford managed to sell Pintos and Crown Victorias with vulnerable
gasoline tanks, numerous gas engine models with electronic ignitions that
would go belly-up on a hot day, and 15-passenger vans which they
discovered had a roll-over problem on the test track. Ford management
concealed the test results. My guess is that this sort of thing goes
all the way back to the Model T. Henry Ford was apparently a steller
example of a man possessed by corporate ethics.
>
cheerz, Eric
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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