Some final comments and observations …
I have been asked how I would compare the SA.97 to the Samuel & Hutton CT-
I thought it would be interesting to describe the controls on the SA.97. The Brilliance and Focus controls are self explanatory. The Sweep Generator has a single potentiometer control labelled ‘Sweep Centre’. As one would expect, this can be used to adjust the sweep such that the output is symmetrically centred on 40MHz. The pot shaft is slotted so it may be that in practice there was no knob on it. There is nothing behind the blanking cap.
The Lin/Log Amplifier module has a switch for selecting Linear or Logarithmic gain and an adjustable gain control. The latter only appears to be effective when ‘Lin’ is selected.
Along the bottom we have the X-
Then we have the Y-
control signal. For this it is necessary to make appropriate adjustment to the Sweep Centre control on the Sweep Generator. As you can see there is a distinct lack of annotation other than control labels.
I have to admit that I find the SA.97 a rather odd piece of ‘Production Test Equipment’.
I myself am ex-
18 Nov. 2015:
I am indebted to Andy Jackson, G8JAC for identifying the end user as the RAF
by deciphering the legend on the left thus …
Section 10S is electronic test equipment. However, there was an interim period when the "last seven" digits of the Nato Stock Number were used, prefixed by the old stores catalogue section title. Now, electronic test equipment is NSN Class group 6625.
We know that it's British so the Nation code will be 99. Put all that together and
we get: 6625-
Put that into Google and Bingo! You will get cross-
So, your Wobbulator is (a) a Nato coded item and (b) it was used by the RAF.