[G8BBZ]

Hi Cecil,
Nice pics - thank you.
I see that there is a toggle switch on the front panel - below and left of the bandswitch - which is not present on the R50. What is the function of this switch? - I just cannot read the legend on the photo.
It also looks like the audio output transformer is located on the chassis immediately behind the front panel on the left side adjacent to the output valve. This was the original location in the R50 but the output transformer was relocated to the separate power supply chassis very early on (from ser.No.50 maybe) so if this set has the transformer in the original location it may infer that it is very early. Have you found any date codes on any of the components?
I am not sure about that strange serial number. The R153, like the R186 and R50B, was a variant of the production R50 rather than a separate product line in its own right. As such I see no reason why it would have gone through a pre-production stage. Also, the nicely engraved label looks a bit 'posh' for pre-production.
A fascinating bit of kit in exceptional condition.
cheers
Peter G8BBZ