[PVRCNC] PVRCNC Digest, Vol 76, Issue 6

[Chris Plumblee]

Magic metering, I suppose.

When N4TO passed away ~2 years ago, I helped work a couple of hamfest
tables clearing out his estate. At the time of his death Vic had two
Alpha 78 amplifiers and about 12 high power (2kw) HF wattmeters. We
did one hamfest without testing much of Vic's gear, selling the
equipment as-is. For the second hamfest we tested the amplifiers
against one of Vic's wattmeters. Imagine our surprise when both of
Vic's Alpha 78s, when run very conservatively with >100w drive, output
1200-1300w as measured by Vic's Diawa wattmeter. Intuiting that that
particular wattmeter was defective, we substituted 5 or 6 others from
the stack. Most did not read as high, but all were quite a bit higher
than a Drake WM-4 provided by one of my fellow FCG members. We decided
pretty quickly that Vic had adjusted all of his wattmeters to read
high in order to prevent guest-ops from attempting to drive a 2kw
input amplifier to 1.5kw output. The amp could operate very
comfortably at 900-1000w actual output, while an outboard meter
indicated nearly 1.5kw.

Chris WF3C

On Tue, May 18, 2010 at 12:00 PM,  <pvrcnc-request at mailman.qth.net> wrote:
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> Today's Topics:
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>   1. Alpha 9500 magic (Brian Alsop)
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> ---------- Forwarded message ----------
> From: Brian Alsop <alsopb at nc.rr.com>
> To: PVRCNC <pvrcnc at mailman.qth.net>
> Date: Tue, 18 May 2010 15:21:07 +0000
> Subject: [PVRCNC] Alpha 9500 magic
> Looking at the June QST ad on page 113 for the Alpha amp yielded an interesting conclusion. The amp must be 100% efficient!
>
> The ad shows the amp putting out 1500 watts forward power with a plate current of 600ma and plate voltage of 2500V.
>
> Am I missing something?
>
> 73 de Brian/K3KO
>
>
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-- 
Chris Plumblee
Voice-407.898.2534
Cellular-407.924.1767