[Test-Equipment] MAX-100 frequency counter info (by CSE or Global Specialties)

[Steve]

At 12:52 PM 1/17/2010, you wrote:
>A particular problem, the high order (left most) digit always stays lit and
>is normally the same value as the low order (right most digit) making it
>impossible to read any frequency above 9.999.Mhz.  If anyone can help with
>either of these items I would be most grateful.

Are the digits 7-segment LED displays? If so, normally, what goes bad 
is the driver/decoder chip for that digit. It can affect other, 
higher-reading digits if the driver/decoders are daisy-chained such 
that an overflow then drives the next higher driver/decoder. Try 
replacing that driver chip; install a socket instead of putting the 
chip in the board for easier replacement in the future.

Why do those driver/decoders go bad so often?? I don't know but have 
seen it on just about every older freq counter that no longer 
displayed properly but was still counting.

Steve, K0XP



>Thanks
>
>Brian VE7BGC
>
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