Wes Stewart wrote:

Hey, if you started using SA's in the 60's it's perfectly natural. [g]
We had one (don't remember the no.) that predated the 141's. Two
boxes that took up about three feet of rack space. Drifted like crazy
and used harmonic mixing so you didn't know what the hell you were
looking at.

I remember using one of those. It had the 140S display unit, a point contact
diode in the unbalanced mixer. The diode was under a cap on the front panel,
so you could tap it to improve its sensitivity, or replace it. Hot stuff
once. Hard to believe that anyone could get useful work out of one. I had
an Ailtech 707 in the same lab, you can guess which one got used.

The Ailtech was nice because other than the logging amplifiers, and the display,
there was nothing custom in the unit. It was a collection of microwave modules,
dbm's, yig vco's, ... all tied together with 141 semirigid hardline.

-Chuck