On Mon, 5 Apr 1999 11:56:13 -0700 Rich Measures <measures@vc.net> writes:
>
>>Well I cant speak for the initial Viewstars. Maybe reducing the HV
>was
>>their way to do a fix.
>
>? Reducing the supply of HV always reduces amplification. Less
>amplification ususally means less chance of oscillation.
>
>>However when B&W bought the rights to the 2500A I did a bit of work
>on them.
>>
>>And yes, the first units I saw had some funny looking stuff in the
>>suppressor area that was Rich's magic fix.
>
>? Mr. F. E. Handy recommended damping VHF parasitics with
>resistance-wire in 1926.
What was VHF in 1926?
>
>
>> They were the first thing that was thrown away.
>>
>>No voodoo at all, no mysterious VHF gremlins.
>
>? Higher VHF Q (less VHF-resistance) dampens VHF parasites better?
A well designed suppressor does suppression period. Most commercial
manufacturers/engineers understand the relationship between resistance
values, and L for a particular tube and/or circuit. Most hams read QST,
etc and assume one size fits all.
>>
>>Just a slight readjustment of the PI-L, changing a few caps, and
>>selecting the proper resistors for the original suppressors.
>>
>? Naturally, the details of these proper changes were omitted because
>
>they are apparently too esoteric for us non-"experts" to understand.
I guess you must have been busy writing one of your canned Hi-Pot
messages the last time I detailed the changes.
Anyone with a B&W PT-2500A Serial # 001 thru 025 contact me for update
info. Many were done here or at the factory once the changes were
approved.
I suspect much is applicable to the Viewstar but I've no idea what
changes they made during production.
73 Carl KM1H
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