>
>> Ä I lost count. -------- Please describe how you remove each type of
>> anode-cooler. What does a ''barnacle'' look like? Is this a common
>> occurrence? > Cheers, Tom
>
>Barnacles are described in many texts. Copper actually grows
>barnacles when in a vacuum.
[chortle] these are long copper filaments that burn away easily. Are
3-500Z anodes made from copper?
>
>This entire topic has been discussed here before.
? We have heard taurine feculance here before..
> Repeating it with
>you will do very little good. You seem to think an ionized path
>inside the tube will always leave an arc point marking that can be
>easily located, and a barnacle will remain long after an arc.
>
I have opened dozens of kaput 3-500Zs from amps that reportedly had a
big-bang. I have yet to see a barnicle.
>Tube faults like that are intentionally removed by controlled arcing,
>and uncontrolled flash will do the same thing.
>
>If the tube repeatedly arcs, it needs to be replaced.
>
>I'm more interested in your claim the grid fails to be a shield in the
>3-500Z at 80 MHz, and the grid capacitors raise that frequency.
>How do you determine that?
>
A dipmeter. If the grid were resonant where you claim, the amplifier
could not oscillate at c. 110MHz.
>If I do a plot of S12 or S21 on a cold tube in a test fixture, would
>you like to put it on your web page and remove the incorrect data?
If no such dips occur in a SB-220 at the frequencies you claim, the
''incorect data'' is not mine.
later, Tom.
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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