Deflux those boards boys and girls!

[Grant Richter]

Hi all,

Many years ago I picked up some Serge series 76 panel racks.
These were early enough in the game to have been kits
(actually I think they were some of the first 10 - 20 units).
Everything always worked great except for this unpredictable
instability in the NTO's. It was like a flicker noise in the frequency
modulation circuit, and that's what I chalked it up to for years.

Anyway, awhile back I got ticked at it enough to take the racks apart
and look at everything. Guess what, the boards were never defluxed!
So I got out my big glass tray and 90% isopropyl alcohol, went outside
far away from any flames or pilot lights, and cleaned the
living *$# out of the boards. Then blew them off (gently) with compressed
air.

Now the oscillators are like rocks, no drift. Doh!
(They did require recalibration.)

Moral of story: Always deflux printed circuit boards! It does matter!