The question, ‘What defines an RA17 MK2 from a MK1?’ is a common one and anyone could be forgiven for thinking that there must be precise delineating features. However, the more I look into the issue, the more muddy the waters become. BUT, before I go any further and it is pointed out by someone else, some RA17 MK2s do actually state MK2 on the serial number plate as in the picture below. It wasn’t always like that though …
There is even a school of thought that marks the boundary between RA17 and RA17 MK2 thus: ‘those with serial numbers 511 and above are MK2s’. This premise is probably based on the annotation at the bottom of the circuit diagram in early RA17 manuals. See the picture below.
But that ‘argument’ doesn’t hold much water either. A few years ago I was given the
remains of RA17 Ser. N573. It was missing the VFO-
Thus, you would think that here is clear evidence of where a MK2 differs from what
we will call a MK1. But you would be wrong because the photograph on the right is
in fact from RA17 N558 and obviously pre-