>>>>> During a telephone conversation with Mr. Rauch, he told me that he had
>>>>> seen lots of parasitic oscillation damage in SB-220s.
>>>>
>>>>Rich,
>>>>
>>>>I'll speak for myself, since I am here.
>>>>
>>>>I never told you I saw damage from *VHF* oscillations in SB-220's
>
>I don't want to say that I am denying that Tom may have changed his
>story. So, let me ask the question. Maybe we can get to the truth:
>
>Tom: Did you say that you have seen parasitic oscillation damage of
>*ANY* kind in SB-220s?
>
>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.
>
>So Tom, please clarify for all of us what you told Rich.
>
>Rich: In your conversation with Tom, did he *SPECIFICALLY* say that the
>damage was due to VHF oscillations or oscillations in general?
>
[chortle] . . The article I wrote that he telephoned *QST* and me to
complain about was on the subect of VHF parasitic oscillations. As I
recall, I was trying converse with him about bandswitch arcing due to VHF
parasitic oscillations.
The moral to the story is record telephone conversations for the purpose
of impeachment -- if needed. Those who do not adjust things have nothing
to fear.
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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