Ian says:
>For example, with an ideal 100nH/100ohm network, it only takes 29nH of
>series lead inductance to bring the equivalent parallel resistance up
>to 166 ohms at 30MHz [1].
I was assuming (possibly mistakenly) a suitable test fixture, so that the
connecting lead lengths dropped out of the equation.
I presume by 'ideal', Ian means an 'ideal 100nH' and an 'ideal 100 ohms' -
not that 100ohms and 100nH is the 'ideal' network!
In the final analysis, as Ian intimated yesterday, it's basically a process
of empiric eclecticism. I still believe in being gentle with the HV and/or
screen voltage in doing the parasitic search, so as to be kind to the
tube(s), though.
>[1] That calculation took about 1 minute total, using the NETCALC
>program which is downloadable from my web site. (New users can expect to
>take a bit longer :-)
That calculation took under 30 seconds on my HP41, with series parallel
conversion programs! Pity the HP 41 isn't made any more - it's a superb
calculator.
73
Peter G3RZP
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