[hagtech]

Oh my, talk about a boneheaded move.  I discovered an error in the UFO schematic (from two years ago), that causes it to operate at twice the frequency it should.  In short, all UFOs are operating at 150Hz!  They still work, but the strobe pattern is not as visible as it should be.

The fix is simple.  And it works far better.  Those tiny little dots become much more clear.  All you have to do is remove pin 14 from U1.  Then tie the pin 14 hole to pin 15 with a small jumper wire.  That's it.  Manual has been updated.

jh

[analog97]

Thanks for the correction as I thought I may have been missing something in my UFO.  My problem is my skill/understanding level to fix.  It appears as if I must de-solder U1, then identify pin 14 and cut it off the chip.  Then re-solder the chip.  Then solder a thin wire on underside of PCB to connect pins 14 and 15.
1.  Is this correct?
2.  I can't identify these 2 pins from the circuit posted.  Using the U1 chip notch on the bottom as a reference, where are pins 14 and 15?

Thanks for help.

[hagtech]

Do NOT desolder U1.  That's way too much work.  Just chop off pin 14 leg right at the body of the chip.  Use a razor blade or small nipper.  Then heat the solder joint and pull pin out the top.  Once the pin is removed, you can remove solder from hole.  This makes it easy to add jumper wire.  Solder wire into hole, then bend over and solder to existing pin 15.

U1 is the CD4060 oscillator/divider.  The one next to the crystal.  Pin 1 has the square pad.  All others are round.

jh

[analog97]

Thanks!  Re:pin numbering, I just downloaded an EE course outline from Notre Dame that showed me how pins are numbered.  I now understand fully (that's dangerous)

[analog97]

I just finished and tested the de-bugged UFO.  Now I see what it is supposed to do and like it very much.  The outer band of strobe spots (for 33.33rpm) appears solidly fixed, i.e. the dots do NOT appear to move.  Thanks for posting the "bug" and the "fix".