Well Carl, that is strange indeed as I never had any of those problems that you
are talking about with my PT-3000A which is very similar to the PT-2500A except
for the 8877 and factory installed qsk. Also, the Hammond power supply had a
much better plate transformer. I don't know what they did wrong in the US when
B&W acquired it but it sure wasn't around very long after that. Fern
----- Original Message -----
From: "Carl" <km1h@jeremy.mv.com>
To: "Dwayne" <863@telus.net>; <amps@contesting.com>
Sent: Wednesday, March 24, 2010 5:12 PM
Subject: Re: [Amps] B&W PT-2500A HF Amplifier
> Ummm, I never said that B&W used a different switch or transformer. AFIK,
> they could have used a US built transformer but I never asked, even when I
> was at the factory.
>
> As far as the Pi-L, I beg to differ as it was a severe problem that went
> thru 2 revisions in the US before it was stable on all bands and under all
> possible conditions such as all out contesting for 48 hours non stop. A new
> parasitic suppressor design was also implemented.
>
> If you read the thread you will see that I was comparing the final version
> B&W amp to other 2 x 3-500 amps on the market and concluded it was the best
> of the breed. Viewstar deserves a good part of the credit.
>
> Carl
> KM1H
>
>
>
>
> ----- Original Message -----
> From: "Dwayne" <863@telus.net>
> To: <amps@contesting.com>
> Sent: Wednesday, March 24, 2010 5:48 PM
> Subject: Re: [Amps] B&W PT-2500A HF Amplifier
>
>
>>
>> ----- Original Message -----
>> From: "Carl" <km1h@jeremy.mv.com>
>> To: "Zeitler, Lane LT, FST-1" <zeitlel@cpr3.navy.mil>;
>> <Amps@contesting.com>
>> Sent: Tuesday, March 23, 2010 4:14 PM
>> Subject: Re: [Amps] B&W PT-2500A HF Amplifier
>> Carl....
>> The PT-2500a Viewstar Always had the Mod #86 band switch.. I've had a
>> number of these amps here and that band switch was common befors B&W ever
>> got it... As well the pi-L tank circuit was never a problem.. What was a
>> problem was that Potter es Brumfield relay timing.. I still have two of
>> these amps and the only mod I've done is a QSK circuit for c.w. Oh and
>> the
>> changes B&W made had nothing to do with inproveing the amp. like the"
>> transformer" change..
>> Dwayne Ve6qx
>>
>>> Yep, Ive seen those in person. The B&W used a massive RSC (now Multi Tech
>>> Industries) Model 86 switch, chimneys, and a healthy transformer.
>>> 160-10M and 1800-2000W out on all bands. I sold about 20-25 as a
>>> distributor
>>> and had a pair of very early models that I did the redesign work on as
>>> loaners for a few years of contesting.
>>>
>>> There is also the Yokagawa P9306 industrial amp that many have converted.
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: "Zeitler, Lane LT, FST-1" <zeitlel@cpr3.navy.mil>
>>> To: "Carl" <km1h@jeremy.mv.com>; <Gary@ka1j.com>; <Amps@contesting.com>
>>> Sent: Tuesday, March 23, 2010 7:04 PM
>>> Subject: RE: [Amps] B&W PT-2500A HF Amplifier
>>>
>>>
>>> Sigma made a 3-500Z amp in the late 70's/early 80's that was very well
>>> done. They apparently did not import many to the states b/c you rarely
>>> see them for sale. I had one about 15 yrs ago, the weak link was the
>>> bandswitch. It was also an absolute nightmare to service.
>>>
>>> Tokyo-Hy Power used to make a "HL2K" that ran a pair of 3-500Zs. It too
>>> was very well done. Not very easy to service either.
>>>
>>> Lane
>>> Ku7i
>>>
>>> -----Original Message-----
>>> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
>>> On Behalf Of Carl
>>> Sent: Tuesday, March 23, 2010 12:08 PM
>>> To: Gary@ka1j.com; Amps@contesting.com
>>> Subject: Re: [Amps] B&W PT-2500A HF Amplifier
>>>
>>> Viewstar was Hammond and since they couldnt crack the US market they
>>> approached B&W.
>>>
>>> The Pi-L tank had a few problems causing lots of smoke and that was
>>> redone.
>>> Its the best of the 3-500 amps but its high price limited sales and it
>>> was
>>> discontinued.
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>>> Tony,
>>>>
>>>> I gave my Dad what I believe was the original version of that Amp,
>>>> the Viewstar PT-2500A made in Scarsborough, Ontario. He uses it
>>>> daily. I've been so wrong before but I think B&W bought the amp
>>>> design from Viewstar.
>>>>
>>>> If you can scan those pages I'd like a copy of them myself.
>>>>
>>>> Thanks,
>>>>
>>>> Gary
>>>> KA1j
>>>>
>>>>> Cleaning out here and came across the "73 Magazine" review of the
>>> above
>>>>> amplifier (3 pages). If you have this amp and would like this
>>> original
>>>>> copy review, I'll be happy to send it along to you.
>>>>> 73
>>>>> Tony, W4FOA
>>>>>
>>>>>
>>>>> Watch your thoughts; they become words.
>>>>> Watch your words; they become actions.
>>>>> Watch your actions; they become habits.
>>>>> Watch your habits; they become character.
>>>>> Watch your character; it becomes your destiny.
>>>>>
>>>>> -Frank Outlaw
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>
>>>>
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>>
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