>
>
>
>On Sun, 4 Apr 1999 21:15:05 -0400 "David A. Pruett" <k8cc@ix.netcom.com>
>writes:
>>
>>Brad, et al:
>>
>>I have a very early Viewstar PT-2500A. It was originally the demo
>>unit at the 1984 Dayton Hamvention and sold to my friend WA8RRR for a
>>discount. Rick used this amp for eight years before selling it to me,
where it
>>has been a workhorse at my contest station.
>>Plate voltage is right around 3800V. 100W drive produces legal limit
>>output.
>>
>>73,
>>
>>Dave/K8CC
>
>Interesting Dave. Looks like Viewstar made the change then. I have both
>the Viewstar and B&W PT-2500A manuals and both state 3500V in standby.
>Wonder if that was the difference between yours and the "A" version?
>
>Its still IMO the best 3-500 amp made. Too bad neither company could
>market it successfully.
>
? Most of the people I knew in CA, NV and AZ who initially purchased
one-tube and two-tube Viewstar amplifiers experienced intermittent
output-bandswitch arcing problems and returned the ampifiers to dealers
for repair. Within months, no dealer in CA, NV and AZ was carrying
Viewstar amplifiers. It is my opinion that reports of bandswitch arcing
can not be overcome by marketing. . . Since the output bandswitch had
a breakdown potential much greater than the anode supply V, there should
have been no arcing problems from the HF potential present.
. Not long after "Parasitics Revisited" appeared in the September and
October, 1990 issues of *QST* magazine, I received a telephone call from
QST-staffer James "Rus" Healy. Rus told me that he had just received a
telephone call from one of the designers who had been involved with the
Viewstar amplifier. Rus said that this designer described mysterious
problems with an under-development amplifier that sounded to Rus like the
problems might be VHF-related. Rus said he recommended that this person
telephone me - which he eventually did. We talked, however, my guess,
based on subsequent events, is that he balked. .
- Free, unsolicited advice from yours truly: When a tube manufacturer
gives ratings for Amplifier or Oscillator Service, it's nothing to sneeze
at.
- cheers
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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