Eventually the trusty old Beeb succombed to that age-old problem of a worn-out UHF modulator so I set about getting a replacement. Given the problems I had had with the 1770 upgrade, I wanted to be absolutely sure the replacement part would work. The letter above from Watford Electronics is the nearest to confirmation that I got, although I do recall that they sent the wrong one initially, but before long my Beeb was back to normal. I don't recall who fitted the new UHF modulator. It requires soldering so it wouldn't have been me as I didn't go anywhere near a soldering iron back then. I am still terrified of the red-hot poker of death to this day.