Hi all,
I've just uploaded the first part of my effort to trace back the history of Philips and Mullard TV tuners. It covers the VHF tuners till 1959.
http://www.maximus-randd.com/tv-tuner-history-pt1
For the next part I'm bumping into the next question:
Mullard was very late with the introduction of frame grid valves into their tuners; whereas all continental tuners introduced the PCC88 in 1956, Mullard only introduced the PCC89 in 1959/60. The likely reason, based on the discussion on this and other forums, is most likely the desire of Mullard to continue using remote cut-off concepts in the RF AGC, which meant they had to wait for the variable-mu PCC89, still in combination with the PCF80.
However, almost immediately the PCC189 (a differently pinned identical valve) and the PCF86 were introduced in 1960. So my question: what did Mullard do? Did they also switch to the PCC189-PCF86 valves like the rest of Philips, or did they stay with the PCC89 and switched to the PCF86 for the mixer-oscillator?
Who knows the Mullard tuners, their valves and the sets in which they were used?
Cheers, Pieter