Hi Chris,
The R109 I have has a grossly modified power supply. The vibrator and
transformer have been ripped out and two 240v mains transformers fitted, one
delivering 6v and the other providing HT.
Fortunately the original HT rectifier is still there.
I have removed all the non-original power supply components. I have managed
to obtain a 4-pin vibrator socket.
I have an unused vibrator transformer for a Wavemeter Class D, it is marked
with a 6-0-6 volt primary and a 0 -140v secondary.
I wonder if this will work in the R109?