SSG 20 notes, in no particular order:

All part numbers are arbitrary and for our reference only.
R52 was missed off the layout and added later on the back 
of the board.  Earlier versions did include this resistor.

When connected as an SSG, pad S is wired directly topad L 
on the back of the board.
The circuitry between pads F and T isn't used in the SSG.  

It is slightly different to the circuitry between P and S, 
which is the same as in the old schematic (VC Slew / S&H).  

I believe the SSG board was used in at least three other 
modules - Random Voltage Generator, V.C.Slew and the 
Dual Rate-Controlled S&H, the latter two being long 
discontinued.  

The F - T circuitry would probably have been used in the 
Dual R/C S&H.

The SSG20 could be used as a dual V.C. Slew by just missing 
out the P - S section and wiring the "hold" input straight 
into pad L.

Steve

Anyone know if the F - T section or the P - S 
section was used in the RVG?