[Amps] Ten Tec HERC II model 420 ---- TSPA

[Jim Brown]

On Fri, 20 Jan 2006 14:02:41 -0700, John T. M. Lyles wrote:

>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.

According to the manual, the 420 (Herc II) is rated 550 watts output CW, 
RTTY, and SSB, 1 kW input; SSB is rated for continuous operation, CW/RTTY 
is rated for a 50% duty cycle with maximum continuous key-down of 15 
minutes. Efficiency and drive required vary a bit from one band to another. 

>From conversations on various email lists, I have learned that many owners 
of the Herc II use it with some P/S other than the TenTec (which they say 
is rated 100A, and designed to run both the amp and the exciter at 100w). 
One popular configuration is a deep-charge battery with a suitable float 
charger. Another is a pair of Astron 70A units (which is what I am using). 
FWIW, it should run just fine on SSB on one of the Astron 70A supplies. 
Because I mostly work CW, I use two. 

Jim Brown  K9YC