[Premium-Rx] Racal RA1778/9 serials & build dates

[John Nelson]

Having recently been involved in saving a few RA1778s and seeing that they
go to good homes, I'm trying to get to the bottom of a minor mystery. I've
never seen a serial number higher than about 430 for these receivers and the
build dates all seem to be in one of three batches (7904, 7924 and 8048).
With one exception the ones I've come across all have the DE filter set and
an AFC board. 

It's a little difficult to believe that Racal built these receivers in such
small numbers and versions but such seems to be the case. I'd be very
interested in establishing whether anyone owns an RA1778 with a higher
serial number and/or a different filter option and also whether there were
other build dates. 

I'd also be interested in a similar exercise for the RA1779 but these seem
to be even rarer than the 1778!

73 John
GW4FRX