[TenTec] Power supply for Hercules II

Katz Ajamas ajamas.rn at gmail.com
Wed May 10 13:06:04 EDT 2017

I am using a battery at present. It works well but but I do not charge
indoors and with an expectation of increased operating time, charging is
going to be a hassle. Also, once past 20% discharge, it's no better than
the SMPS I have.

The 2SC2879 transistors are supposed to run at 12.5V for best intermod
specs. The HP SMPS supply I have now barely makes 12.3V. There is a good
bit of drop in the stock Tentec cable and some more with the inner
connections.. The connector appears to be rated for the current. Bottom
line, the devices are running at about 11.6V for 500W output.

I'd like to find a matching Tentec supply for a reasonable (caps likely
need to be replaced) price.

Looking around at other options, there is a "Meanwell" brand SMPS at Mouser
and Arrow that makes 13.5V-16V adjustable, has voltage sense lines that can
be wired to the collectors, and can be turned on and off with a TTL signal.
It is class B EMI rated.

In trying to get a handle on the class B spec, I find a radio station on
1.5MHz and has a 400uV/m contour at my location is S7. Alas, the class B
spec is for a conducted "limit" and does not make sense at 250uV as this
will be very sensitive to the impedance of the 'antenna'. Is this the
common mode PtoP that is acceptable at the power leads? In OR out?

The supply is $259 with free shipping from Arrow. Same price from Mouser
but plus shipping. $219 plus $30 shipping from HongKong seller. Mouser
looks like the best bet because they have a 30 day return policy. Unless,
someone who has used one of these can tell me about EMI and also about
whether it is reasonable to turn the supply and Hercules on during transmit
and off during receive. I'm not talking QSK rates. Just between exchanges.

What say?

73, -Bob

-do not look into LASER with remaining eye!

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