405 Philips - UK Vintage Radio Repair and Restoration Discussion Forum

toshiba tony · 3rd May 2017, 3:26 pm

Iv'e been stepping back in time recently and remembered a tv from the 60's. I feel it was a Philips. The odd thing about it was it had two heater chains, and one of them was a 100ma one. the other was the normal 300ma used in most tv's. I think it was 405 only, why they used to do it that way eludes me, but then again Philips were always odd. Anyone help please.

FERNSEH · 3rd May 2017, 4:09 pm

Wasn't just Philips that had two heater chains, the manufactures that used Mazda valves such as Ekco, Murphy and Ultra employed valves that had 0.2amp and 0.1amp heaters. The two heater chains would merge to supply the 0.3amp heaters of the CRT and tuner valves.
It was the Philips sets made about 1949/50 that employed the three 0.1amp heater chains. The three chains merged to supply the CRT heater.
Models like the 385U employed a PZ30 HT rectifier valve, the heater of this valve was inserted at the "top" of the heater supply.
After 1951 Philips employed the "World Series" valves with 0.3amp heaters.

DFWB.

toshiba tony · 3rd May 2017, 4:28 pm

Thanks for clearing that one up, Iv'e seen a lot of your posts and you certainly are up to it, on old gear I mean! Cheers,
Tony Walker

3rd May 2017, 3:26 pm	#1
toshiba tony Heptode Join Date: May 2006 Location: Accrington, Lancashire, UK. Posts: 978	405 Philips Iv'e been stepping back in time recently and remembered a tv from the 60's. I feel it was a Philips. The odd thing about it was it had two heater chains, and one of them was a 100ma one. the other was the normal 300ma used in most tv's. I think it was 405 only, why they used to do it that way eludes me, but then again Philips were always odd. Anyone help please.

3rd May 2017, 4:09 pm	#2
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: 405 Philips Wasn't just Philips that had two heater chains, the manufactures that used Mazda valves such as Ekco, Murphy and Ultra employed valves that had 0.2amp and 0.1amp heaters. The two heater chains would merge to supply the 0.3amp heaters of the CRT and tuner valves. It was the Philips sets made about 1949/50 that employed the three 0.1amp heater chains. The three chains merged to supply the CRT heater. Models like the 385U employed a PZ30 HT rectifier valve, the heater of this valve was inserted at the "top" of the heater supply. After 1951 Philips employed the "World Series" valves with 0.3amp heaters. DFWB.

3rd May 2017, 4:28 pm	#3
toshiba tony Heptode Join Date: May 2006 Location: Accrington, Lancashire, UK. Posts: 978	Re: 405 Philips Thanks for clearing that one up, Iv'e seen a lot of your posts and you certainly are up to it, on old gear I mean! Cheers, Tony Walker