Equipment with mixed technologies.

[Peter.N.]

In the early days of transistors there were only germanium ones, they were the ones that I gained my experience on anyway. The technology was similar to early valves with coupling and output transformers, very simple, when silicon transistors came along the circuitry got a whole lot more difficult to work on owing to direct coupled arrangements which meant you didn't know where to start with fault finding.

Peter

[Synchrodyne]

The attached SGS-Ates advertisement from 1976 speaks to the use of germanium transistors in UHF TV tuners well into the silicon era, and also to the polarity issue, in that silicon PNP transistors were developed to do the job.

The highlighted items in the attached page from Wireless World 1965 June illustrate that at the time, development of older, intermediate and new technologies was ongoing. TI had just introduced a range of silicon PNP power transistors whereas Thorn-AEI was introducing both a range of germanium complementary power transistors and a new output valve, the EL506. And at that time, the first consumer-oriented analogue ICs were not far away. So multiple technologies were concurrently current, as it were, although at very different stages of their respective life cycles.

Cheers,

[Hybrid tellies]

An interesting thread. I have always been a fan of hybrid tv's. My Decca Bradford colour tv uses germanium transistors in the UHF tuner, silicon transistors in the IF and Decoder stages, including the three video outputs, one Motorola MC1351 IC in the sound inter carrier stage and 6 valves for the timebase, frame, line and sound output stages. This was common practice in many black and white and colour televisions from the early to mid 1970's.