[TenTec] Question about a memory keyer ...

[Tom Scott]

Forgive me for asking a question not directly about Ten-Tec, but I picked up
a new keyer this past weekend at a local Hamfest and have a question about
its use (...it is connected to a Ten-Tec, does that count?).

I got an MFJ Grandmaster Memory Keyer at too good a deal to pass up. The
problem is that it seems to be designed to only remember its memories when
the power is applied. Knowing there are a lot of fists on this list, I
thought someone else out there might have experience with this keyer. Is
that how your's behaves?

I thought perhaps there was a memory backup battery that had died, but after
extensive tracing of the circuit, it seems not. It would appear that it can
be either powered from an internal 9v battery or from an external external
power source, but when you turn off the power switch, there is no provision
in the circuit to power the SRAMs that are used for memory storage. So of
course, they come up entirely random. This seems like quite a nuisance! If
I'm correct, and that is how its designed, I think I'll either have to
modify it, or trade it in on a better one.

Anybody have experience with this keyer? Does this seem like reasonable
behavior for a memory keyer? There appear to be a couple of unused poles on
the power switch, so it may not be too hard to make it use the internal
battery as a backup battery. The difficulty comes in when you try to prevent
the control circuitry from writing garbage in ram when that control circuit
is being powering up and down, but even that can be solved.

Thanks! 73's

- Tom
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   Tom Scott     -    Wyle Electronics    -    KD7DMH
   10300 SW Nimbus Ave #PB, Portland, OR 97223
   503-603-1931 - TEL   503-684-6620 - FAX
   503-504-1583 - Cell    503-604-8651 - Pager
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