[TenTec] Resurrecting Hercules 444 amp

Mike Hyder -N4NT- Mike_N4NT at charter.net
Fri Oct 19 07:23:21 EDT 2012

Hi Pat,

Speaking only from my dim memory of my 444 amp as it was before it caught 
fire, was successfully repaired at Ten-Tec and returned with their note that 
it was the last time a 444 would darken their doors...

I used the 444 with my 546 Omni-C and liked it pretty well except when its 
fan went into overdrive, sounding like a 747 landing with engines in 
full-reverse. Bandswitching on the amp was controlled from the Omni by a 
stepping-switch or stepping-relay in the amp. I asked Larry Wirth (maybe 
Worth) if the Corsair II could be equipped with contacts to operate the 
444's bandswitching and what that modification might cost. He took me into a 
conference room or library and we met with Al Kahn. Larry explained my 
questions about the Corsair II. Al asked what rig I was currently using with 
the amp. I told him of my Omni-C and his response was, "If you've got an 
Omni-C, you don't need a Corsair II."

A year or so later, the amp failed. I saw no flames but, as my Granddaddy 
said, "Where there's smoke..." I drove down to Sevierville and left my dead 
444 with them for repair. When I picked it up, I was told that my 444 was 
the last one they would repair and mine had just had it's last trip across 
their bench.

Without knowing, I surmise that the stepping-switch was probably NOT the 
actual bandswitch but likely actuated various relays to accomplished the 
needed switching. If this be true, then failure of one of the relays might 
explain a trouble which occurs only on 80 meters. I believe there are 
low-pass filters for each band which might also be worth an inspection.

Best of luck. Once Ten-Tec told me my amp would be considered "beyond 
repair" in the future, I sold it... many years ago.

73, Mike Hyder  -N4NT-

----- Original Message ----- 
From: "Pat Moore" <pmoore44 at gmail.com>
To: <tentec at contesting.com>
Sent: Thursday, October 18, 2012 14:37
Subject: [TenTec] Resurrecting Hercules 444 amp

>I was given a Hercules 444 amp, and I have it working on 160, 40, 20, and
> 15. However, on 80 M, the I/V light comes on with any more than 10 watts 
> of
> drive. The amp is stable and produces rated power on the other three 
> bands.
> Any ideas why there's a difference on 80?
> I know TenTec abandoned this amp when the transistors became unavailable,
> but mine still works, and I'd like to get some use out of it.
> Tnx ex 73 de AL7L 

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