UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Websites (https://www.vintage-radio.net/forum/forumdisplay.php?f=38)
-   -   Philips TV tuner history (https://www.vintage-radio.net/forum/showthread.php?t=142320)

neutronic 19th Dec 2017 10:36 pm

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.

Nuvistor 20th Dec 2017 2:41 pm

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

brunel 16th Jan 2019 10:19 am

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.

G8HQP Dave 18th Jan 2019 2:16 pm

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!

Andrew2 18th Jan 2019 4:20 pm

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.

neutronic 27th Jan 2019 9:06 pm

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.

Nuvistor 28th Jan 2019 7:56 pm

Re: Philips TV tuner history
 
Quote:

Originally Posted by neutronic (Post 1114782)
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.

The web site is well worth a visit, a tremendous amount of research has been done by the author.


All times are GMT +1. The time now is 11:46 am.

Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.