[Lowfer] frequency counter calibration

[Zack Widup]

The version of the counter I built used an ICM7216DIPI counter chip. This
chip is long obsolete and hard to find these days. I would go fomr
something more modern these days.

73, Zack W9SZ


On Fri, Jan 25, 2013 at 2:34 PM, Douglas D. Williams <kb4oer at gmail.com>wrote:

> I am not going to give Optoelectronics close to $100 to turn a screw.
>
> Time for them to "build a bridge to the 21st century", to coin a
> phrase from Bill Clinton. :-)
>
> 73, Doug KB4OER
>
> On Fri, Jan 25, 2013 at 3:13 PM, KD7JYK DM09 <kd7jyk at earthlink.net> wrote:
> > : > After contacting Optoelectronics, they want $75 plus return shipping
> to
> > : > calibrate it. "Calibrating" it simply involves supplying it with a
> known
> > : > frequency standard of 10 MHz or greater and turning a small screw on
> the
> > : > front of the unit. It doesn't even have to be opened up.
> >
> > I just went over this with them...
> >
> > I need a new calibration variable capacitor.  I tried to cal mine about a
> > decade ago and the part went crunch.  Trying to get a new part from
> > Optoelectronics, it's $5 off the book, $20 or more on the book, $75 to
> have
> > them do it, solder two leads and turn a screw...
> >
> > I got a handful of new parts just by asking around.
> >
> > Haven't repaired mine yet, but I did run it on a stable source, though
> off,
> > it did dance around in the 100 Hz place at 470 MHz.
> >
> > Kurt
> >
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