Philips TV tuner history
I found these interesting links at the Dutch antique radio forum:
Two parts: https://www.maximus-randd.com/tv-tuner-history-pt1.html and: https://www.maximus-randd.com/tv-tuner-history-pt2.html Jard N. |
Re: Philips TV tuner history
Pieter is writing up fantastic articles about the subject, we are all waiting for part 3.
See these links to forum posts. https://www.vintage-radio.net/forum/...d.php?t=141472 https://www.vintage-radio.net/forum/...d.php?t=142298 |
Philips TV Tuner History pt1 1945-1960: Valve-based VHF Tuners
https://www.maximus-randd.com/tv-tuner-history-pt1.html
4 pages, you might have to change pt1 pt2 pt3 pt4 as some of the links appear to be faulty. |
Re: Philips TV tuner history
A minor mistake in part 1 is where he says that 6U8 is PCF80; it is actually ECF82. He probably meant to say 9U8 = PCF82 - the 300mA version.
He says that the coil in a cascode between the lower anode and the upper cathode forms a tuned circuit, which is tuned to the middle of the frequency band for Band III. It might be more accurate to regard this as a short section of lumped transmission line. Its role is basically to compensate away the valve capacitances so they don't shunt the signal away. Part 2 explains something which always puzzled me: why is there both PCC89 and PCC189, with almost identical characteristics? The answer is that PCC89 has the same pinout as PCC84, which was preferred in the UK. PCC189 has the same pinout as PCC88, which was preferred in much of the rest of Europe. Maybe an example of Mullard reminding everyone that although it was owned by Philips it did not have to think like Philips in all matters? He also explains the difference between PC88 and PC86. When talking about noise figure he says that a passive network will not add noise but merely attenuate the signal. This is not true; a passive network will add thermal noise. Anyway, a fascinating and valuable source of information. If only there were more websites like this! |
Re: Philips TV tuner history
Absolutely wonderful reading. Obviously a huge amount of work has gone into the research and presentation. I was particularly interested in the transistor UHF tuner section, as I had quite a collection of 'liberated' ones with which I poked about on UHF by altering the tuning range to tune above or below their normal coverage. A 35 MHz IF amp was followed by a mixer/osc with a second IF at a few MHz (can't remember now!). Using this connected to the rooftop TV aerial I discovered the local radio station's studio to transmitter link on something like 900 MHz and of course lots of interesting stuff around 450 MHz. Keeping it on-tune was interesting. Happy days before we had scanners! Around 1974 I think.
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Re: Philips TV tuner history
The next two articles with semiconductors.
pt3 : https://www.maximus-randd.com/tv-tuner-history-pt3.html and : pt4 : https://www.maximus-randd.com/tv-tuner-history-pt4.html but in fact it is more decent to visit the website of the author, who earns all the credits for these publications to show the full range of his knowledge and interests. https://www.maximus-randd.com/ Jard N. |
Re: Philips TV tuner history
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