PYE MASTERTOUCH

NOTES	A most unusual design from Pye. The usual push button or rotary tuner is replaced by a motorised unit allowing the channels to be changed via a remote control unit. The one and only control on the front is a push button for channel changing. The remote control unit, which also includes the volume and brightness controls, can be attached onto the side of the set when not in use. Unusual, yes, innovative, maybe, well designed - no ! The huge heavy motorised tuner assembly is attached by three or four bolts onto the front of the cabinet. However there is no sideways support which is a shame really since the lever (indicated by an arrow in the above pictures) that opperates the 405-625 system switch also opperates sideways onto the main chassis. I can imagine after a while instead of moving the system switch the lever simply rocked the tuner assembly from side to side ! Other poor design points - and Pye certainly aren't alone in this - is the lack of retaining clips for the valves which are mounted sideways and are just asking to fall out of their sockets. Fair enough on a set that never moved, however this is supposed to be a transportable set. Since this set only uses 8 valves instead of a usual complement of 13 or 14, the series connected heater chain is run via a half-wave rectifier, a method used by many manufacturers. If this rectifier fails short circuit then everything in the heater chain would be damaged, particularly since the set would still appear to be working. A very simple circuit can be used such that this fault could be made to cause loss of frame lock - the viewer would then know something was wrong. Trouble is the boffins at Pye were probably so busy with the tuner unit that they didn't have the time to d*ck about with trifling little protection schemes.
SERVICE DATA	I'm pretty sure the main chassis is the same as that used in the Pye model 40F, which is covered by the Trader seheet 1781 although there is no mention of the thumping great tuner unit. Some obvious differences though are the 40F uses an auto-transformer for mains voltage selection whereas this set uses a set of dropper resistors.
CURRENT STATE	The odd bit of trim and woodwork needs re-glueing, nothing serious. However by far the worst bit is the sad remains of the remote control. I think there would have been a push button running the full with of the top of the unit which would be the channel step button. I'm also pretty sure that the metal sticking out the side was protected by something, since after all it is the mains on/off switch !. The tube may well be duff as I believe it has a label attached to it that those in the trade used to attach to duff tubes as a warning to fellow traders. These labels warned of "Much Air, Zero Display, Avoid !" usually just abbreviated to the five letters 'M', 'A', 'Z', 'D' and 'A' ;-)
WHERE FOUND	December 2005 auction at Wotton Bassett for £2. Not bad as there was at least two quids worth of polystyrene chips stuffed in the back !? Even now I often find another chip lurking somewhere.

With the design nearly complete, the boffins in Pye's design department
popped the cork off the champagne and congratulated themselves on
their extremely clever motor-operated tuner. Then the cleaner came in:-

This probably explains why they were then too busy to design in some
valve retaining clips for the valves which in turn explains why one of the
valves fell out AGAIN after I'd already put it back in once. Grrrr.