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Deluxe Memory Keyer with 3072-bit Campacity

Jun 4th, 12:03

WA2FTV

Joined: Mar 3rd 2012, 03:12
Total Topics: 0
Total Posts: 0
Greetings Everybody,

I am wondering if someone could provide some input/help. The following article is an improvement of the famous James Garrett WB4VVF Accu-Keyer. It was written by Robert Cheek (W3VT) in the April 1979 issue of Ham Radio magazine on pages 32-43. The call sign W3VT appears to be a vanity call sign that is assigned to someone else, not Robert C Cheek.

I can get parts from second source suppliers.

I would like to duplicate the keyer portion of this design without the memory portion. The original James Garrett design used two transistors to generate the clock pulses. The W3VT design uses a 555 timer that is located on the memory board. There are two clock signals (CLOCK IN and CLOCK CONTROL).

Does anyone have an idea of how to handle (where to connect) the CLOCK CONTROL signal that originates from the output of a 74123 through a diode on the memory board? The CLOCK IN signal is the output of the 555 on the memory board through an inverter. The CLOCK CONTROL is an output from a 74123 IC on the memory board through a diode. The 74123 is a Retriggerable Monostable Multivibrator.

https://www.americanradiohistory.com/Archive-DX/Ham Radio/70s/Ham-Radio-197904.pdf

Any advice would certainly be appreciated.

Thank You and 73s,

Cedric
Amateur Callsign WA2FTV
Amateur Extra

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