Re: 1502 TDR project

Tom Gardner

I've had a "battery eliminator" that worked in one 1502 but not
another. That's one reason I don't like them. Another is that tabbed C
NiCd cells are easily available, so the battery can be reconstructed.
Battery operation is pleasing; I used one of my 1502s last Saturday in
the middle of a field, to diagnose the cable between a glider's
cockpit and antenna.

You may well be right about the source of a (possibly the) problem,
but using a bench PSU is quick, easy, and eliminates one significant

On 10/12/2019, Mark Pilant <> wrote:
Hi Tom.

> I just increased the size of the capacitor in the emulator and she runs
> first time, every time now.

I have a 2200uF cap, per the TekWiki. Works fine for the 1503, so I expect
there is something else going on in the 1502.

> As he said, gotta pay close attention to the "subtleties" of this one!

That's why I'm still scratching my head. I really need to find some (of
rare substance) time to probe with my scope. That way I see what is
(At least I hope :-)

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