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[TenTec] Re: Alternate Power Switching

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Subject: [TenTec] Re: Alternate Power Switching
From: royanjoy@ncn.net (Roy Koeppe)
Date: Thu, 12 Aug 1999 17:32:13 -0500
Jerry said:

"But if it was my FET regulated linear supply it
runs about 85% at 20 amps load... Unlike Astrons and the like at under
50% efficiency..."

But the effective duty cycle is real low figuring receiving time versus
xmit time, and the actual xmit duty cycle in SSB or CW. The 50%
efficiency figure dwindles to the point of being of no practical concern
with a nice TT xcvr. The price of using just two cheap car batteries is
the main advantage.

I was thinking also about adjusting the float voltage at the filter
caps. (The poor voltage regulation at this point would have a self
limiting effect on the charging current). However, power diodes could be
used in series with the protective fuse to trim the voltage if necessary
to the batts (and a single diode placed back to back with the trimmer
diodes for discharge function). BTW, I think I recall the voltage at the
caps in my old Heathkit 20A regulated supply is about 28. Haven't
measured a TT supply.

73,     Roy         K6XK

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