FS: Ten Tec Centaur Amplifier

[Jim Sheldon]

I have available for sale one TenTec Centaur HF amplifier.  It uses 3 811A
tubes in grounded grid, and has a built-in QSK/sequencer board.  QSK was
factory stock with this amp.  This particular model is no longer being made
by TenTec, but most parts are supposedly still available should they ever be
required.  

This one is in very good condition both cosmetically and electrically.
There are minor wear marks on the cabinet, as would be expected.  According
to the manual, it is supposed to put out 650 watts CW and 800 or so on SSB.
It does RTTY nicely at 400W as well.  This is the TenTec recommended power
setting for RTTY. Power output is within TenTec specifications according to
my Bird 43 with borrowed 500 and 1000 watt slugs into a Microwave Associates
50 ohm dummy load.  The original 3 tubes are still good, and I'll include a
brand new matched set of 3 Ryazan (Svetlana) 811A's as spares.

The way the QSK/Sequencer works is thus:  You plug your key/keyer (solid
state output + keying very low current draw) into the key-in.  The key-out
goes to the Key jack of your rig.  You will have to use an external keyer
here, as it is only key to ground, not 3 wire paddles.  The PTT for SSB
works the same way - so ANY transceiver's solid state amp keying circuit
will work as long as it provides + going to ground type keying.  Very little
current is involved so it shouldn't be a problem.  MY IC706MKIIG works very
well with no buffer board whatsoever.  My K2 is QRP only, so it doesn't have
enough drive to run it.  The sequencer board insures that when you press the
key, first the amp switches the antenna, then removes cutoff bias from the
tubes and finally provides keying to the transceiver.  Switching is
accomplished in approximately 7 milliseconds, so it is certainly fast enough
for QSK to at least 30 WPM possibly even faster depending on the QSK circuit
in your rig.  The amp is wired for 220 VAC operation, and has a 15 amp 220V
plug attached to the cord.  It will plug into a standard 15 or 20A, 220V
window mount air conditioner outlet.  It can easily be changed for 120VAC
operation, but it runs much more efficiently on 220.  Also, due to voltage
drop at the higher current required for 120V, the HV in the amp will be
lower, and it won't put out full rated power.

I bought this amp to help me finish my QRO DXCC and have finally
accomplished this so am going back to 99 percent QRP operation.  I've also
done QRP DXCC, WAC and 160 meter WAS so I'm pretty much done chasing any
paper that would even halfway require more than 100 watts.

I've heard it said that, "Two of the happiest days in a ham's career are
when he buys his first amplifier and when he sells it."  This one is for
sale for $575 plus actual packing and shipping via either UPS or FEDEX.  It
is HEAVY, so be prepared to either pick it up in Wichita, KS, or pay the
shipping hi ... The Tubes are horizontally mounted, and are very securely
mounted.  It was shipped to me with the tubes in place, and they survived.
I can either leave them in, or remove them - your choice.

Jim Sheldon - W0EB
Wichita, KS

Serious inquiries only and please off the reflector.


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