>>The reason is that while Tom may have never seen *VHF* oscillation
>>damage, he may have seen damage due to oscillations at *HF*. HF
>>parasitic oscillations can occur in an amp that is not properly
>>neutralized. Especially the two tube variety.
>
>However, in a grounded-grid amplifier, there is no way to neutralize,
>save for within the Conyers, GA, city limits. The good news is that
>below the grid's self resonant frequency, there is no reason to
>neutralize because there is not enough feedback C to support an
>oscillation.
I believe there is some neutralization that can be done in GG amps. The
most important aspect I recall has to do with making sure that there is a
balance between the two tubes. A single tube amp need not worry about
it, but in 2 tube amps there can be a problem. Someone please correct me
if I am incorrect. I don't have Mr. Orr's book handy at the moment.
73,
Jon
KE9NA
ps: Never been to Conyers, GA
--------------------------------------------------------------------------
Jon Ogden
jono@webspun.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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