FERRANTI T1505

Really advanced technology here [snigger]. No dual A.C./D.C. mains either, the heaters for the not-often-found-in-tellies 'E' range of Mullard valves having their own heater transformer whilst the H.T. - always a struggle to get enough volts here and hence would really benefit from a mains transformer - is directly rectified from the mains.

You won't find any poncy energy recovery diodes either, something that had become pretty much standard design by other manufacturers during the previous decade. Perhaps that was because Mullard never thought someone would be dumb enough to use the 'E' range in a telly and therefore only produced 'P' versions of boost diodes. Without the energy recovery diode, I'm impressed it managed to get enough power to scan the C.R.T. - pehaps the total lack of any line linearity control that might have sapped a bit of power helped.

One of their top of the range sets this, having as it does a built in radio complete with highly ornate no-expense-spared designer tuning scale. No attempt for any commonality between the TV and radio sections, the radio is a completely seperate unit right down to having its own weenie little speaker (well, you wouldn't want to wear out the thumping great speaker used by the telly now would you). Having said that, by keeping the telly and radio units completely and utterly seperate, you could at least listen to the radio whilst the telly was bust.

And what to do if you can't design a stable circuit ? Simple, make everything easilly accessible from the front of the set. The amount of wear around the width and horizontal hold controls prove how wise a design idea this was and must have been a blessing for the set's original owner ! Still not stable enough ? Well, time to mention that in the perhaps 12 months before the replacement model was introduced, Ferranti tried no less than three different frame timebase circuits. However, in each instance the same frame sync circuit was used; amazingly, a feed was take from the last but one I.F. stage, fed to it's own personal I.F. stage that was demodulated and fed to the frame timebase.

I bet the service engineer also worshiped the ground the set stood on, with such well thought out positioning of serviceable items such as main fuses. Incidently, the service manual shows the metal rectifier mounted directly below the scan coils but it seems in this version some bright spark finally saw the light and thought "hey, wouldn't all that heating of the coils make warm-up drift even worse ? Lets move it somewhere sensible just like almost every other manufacturer in the freakin' world".