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. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
