ANTENTOP- 01- 2010, # 012

Some Thoughts on Regenerative Receivers

- The RF gain control is internal. At some point, I might put a 10K Ohm potentiometer on the back panel to replace the internal control, which is accessed through a small hole with a screwdriver. However, I find that with either the Ten-tec 1253 and MFJ-8100 that I rarely have to adjust the RF gain control unless I have a very strong station.

- I found it useful to "tie" the toroid down to the circuit board after final adjustment with a dab of hot glue from a glue gun. Very handy stuff.

Both receivers are sufficiently stable for CW and SSB reception. The Ten-tec 1253 seems to show a small amount of warm up drift. I have no idea why this should be. It goes away in about 10 minutes. The best bet seems to be to run it from an external power supply and leave it running all evening.

I have found that external battery operation (12 volt gel cell for Ten-tec 1253 and 9 volt battery for MFJ-8100) is the best bet. The usual "wall wart" or converted PC power supplies generate too much hash at HF for good clean reception.

Both receivers benefit from the use of an antenna tuner to optimize the matching between the antenna and the receiver input impedance.

For further reading and study, Google is your friend. A very good discussion of regenerative receivers can be found in the paper by Ramon Vargas at

http://cidtel.inictel.gob.pe/cidtel/contenido/Publicaciones.php?autor=rvargas

The seminal article by Charles Kitchen is to be found in the November/December 1998 QST. He has an extensive discussion, and shows both photos and schematics of an excellent complete solid-state regenerative receiver.

Also, some very nice material on direct conversion and Wheatstone bridge regenerative receivers can be found at:

http://mjrainey.googlepages.com/radio

A good source of early books on vacuum tube receivers and the like can be found at :

http://www.pmillett.com/tecnical_books_online.htm

I'd like especially thank Rob Grasing for some suggestions on modifications to the Ten-tec 1253 and the source for some of the links that I have suggested, as well as on-going discussion during the development and writing of this paper. It is always good to have a "second set" of eyes during a writing project.

I look forward to hearing from other members of the group for their insights on a always fascinating topic.

73

/paul w. ross

W3FIS

Russian Military/Spy/Partisan 3- tubes Transceiver "Sever."

Regenerative RX + Xtall TX. Produced: 1940- 1945

Band: RX/TX: 3.62-12.25/3.62-6.25

Credit Line: http://www.cqham.ru/trx/sever.html

http://www.antentop.org/

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