[Heathkit] IM-2420 Freq Counter problem

[Jim Shorney]

It sounds like you are missing a bit between a decade counter and a display
decoder/driver. Reseating all the chips would be a good start. The bits are
weighted 8, 4, 2, and 1 in binary (or BCD in this case) so a missing '4' bit
would cause what you are seeing.

73

-Jim
NU0C


On Thu, 25 Sep 2014 17:41:29 -0400, Alexander N. Gerli wrote:

>Hi, gang!
>
>I'm trying to figure out something. My counter does count, but one digit's
>way off - the x10MHz. For instance, if I key up my HT nearby on 146.34/94,
>the counter displays "106.3400" Off by 40MHz. Now, I can't find any such
>anomaly covered in the "ICOD" section of the Manual (naturally...). I'm
>figuring that I need to recalibrate the 10mHz Oscillator inside its
>styrofoam oven. I have another portable counter I can use and it is right
>on. But if it were off by that much, how come the suffix reading of .340mHz
>comes out on the nose? Anybody have any suggestions? Maybe a divider chip
>could be off, but I have NO idea which one. I guess I could reseat all the
>chips  in their sockets?
>
>73,
>
>
>Sandy AC1Y
>
>
>Alexander N. Gerli, Sr.
>548 Allred Mill Road
>Mount Airy, NC 27030-2202

--
“There’s something out of place – let’s go and poke it with a stick.” – The Doctor, "Amy’s Choice"