Wanted to share a simple crystal checker build with you folks in need of testing crystals.
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Simple Crystal Checker
- Thread starter Crossbow
- Start date
That's nice, Crosbow.
Here's my vintage model.
https://nandustips.blogspot.com/2012/07/quartz-crystal-tester.html
73,
Nandu.
Here's my vintage model.
https://nandustips.blogspot.com/2012/07/quartz-crystal-tester.html
73,
Nandu.
Wanted to update this simple crystal checker as there is a part that was not listed on the output. Make sure you add a 0.01 uF cap to it as shown.
Here is a test from a 10.240 Crystal using my Fluke Frequency counter along with using my homemade modified Gooit counter.
Here is a test from a 10.240 Crystal using my Fluke Frequency counter along with using my homemade modified Gooit counter.
I built a little one of these a while back, very similar schematic. It works great!
I was thinking about a v.2 with a few added functions. If there were a switchable capacitor in series with the crystal, it could be used for the G3UUR crystal parameter test. I was also thinking that if I carefully measure the negative resistance of the oscillator and plot that vs frequency, varying that pot would provide the Rm value (turn until it wont oscillate, Rm = Negative resistance + pot value where it quit). I'd have the Rm, Cm, and Lm of the crystal with just that oscillator and a FC. Some day I'll get to it, I hope.
I was thinking about a v.2 with a few added functions. If there were a switchable capacitor in series with the crystal, it could be used for the G3UUR crystal parameter test. I was also thinking that if I carefully measure the negative resistance of the oscillator and plot that vs frequency, varying that pot would provide the Rm value (turn until it wont oscillate, Rm = Negative resistance + pot value where it quit). I'd have the Rm, Cm, and Lm of the crystal with just that oscillator and a FC. Some day I'll get to it, I hope.
Attachments
I took the liberty to make this printable schematic for the archive.
I usually use several programs to rejuvenate large schematics, but in this case it was done with Paint Shop Pro X by copying and pasting the various symbols taken from a template. The fonts and connecting lines is a product contained within Paint Shop Pro. The image is then cropped, reduced to grayscale, and saved without any compression applied. To reduce file size, the saved file is then converted to a jpg with ACDSee v3.1 at 80% compression. I have never found a better jpg compression program than ACDSee. It simply leaves no leftover artifacts like everything else I tried at that compression level.