I just got 3 of these from a discontinued scientific project here. We
are using one to drive a resonator which is used to flip the spin of
ultra cold neutrons which get polarized in a superconducting
solenoid. It is running about 200 watts CW now at 29 MHz, and we
would like to get it up to 500 but the Ten Tec is not rated for 500 W
CW, only SSB or 50% DF I believe. I am looking at another amplifier,
made by Kalmus for the final install. The Hercules II is a nice
little package however. The power supply is not.
73
John
K5PRO
>Message: 4
>Date: Thu, 19 Jan 2006 16:07:01 -0600
>From: "Jim Brown" <jim@audiosystemsgroup.com>
>Subject: [Amps] Ten Tec Herc 444 (original Herc)
>To: "amps@contesting.com" <amps@contesting.com>
>Message-ID: <20060119220710.95E977D44@gw1.nlenet.net>
>Content-Type: text/plain; charset="us-ascii"
>
>On Thu, 19 Jan 2006 12:05:07 -0800 (PST), Dave Haupt wrote:
>
>>The original Hercules I (model 444,
>>ran on 50V, not 12), is no longer supported, due to RF
>>transistor obsolescence. I have one on the bench
>>right now, fortunately the RF devices are fine, and
>>it's a power supply problem.
>
>I've got one too. When I bought it (used), it was wired for
>120V. I rewired it for 240v, and it didn't work -- blew fuses,
>as I recall. What I found was that one of the Molexes was wired
>wrong -- probably built on a Monday morning. Corrected that and
>it ran fine -- except that:
>
>As it warms up, the voltage to which the power supply regulates
>drifts up and causes the protection circuit to engage, which
>prevents it from transmitting. TenTec told me this was a known
>problem, but that since they had to discontinue the amp (thanks
>to Motorola discontinuing the output devices), they had not put
>in the engineering time to fix the drift problem.
>
>Mine is in good shape, but I need to fix the regulator drift
>problem. If anyone knows how, I'd love to hear about it so that
>I don't have to reinvent the wheel.
>
>Jim K9YC
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