UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Valve Items - Philips/Mullard Rimlock-to-Noval Transition

kalee20 · 22nd Aug 2019, 6:05 pm

Yes, 'X' and 'Y' were used for 450mA and 600mA (can't remember which way round though).

'7' as first figure is not always wire-ended, sometimes it is Loctal (eg EM71 - one wonders why this was not designated EM21?)

And '5' existed as first figure, B9G (eg EF50). But it was not a common base, though the sheer quantity of EF50's produced rather made up for it!

'B' as second latter didn't always mean diodes sharing the same cathode, EB91 has for instance separate cathodes (there is also an EAA91!!). In the EABC80 it's a moot point whether the 'B' refers to the two FM diodes (one completely isolated, one sharing the triode cathode) and the 'A' the AM diode (which also shares the triode cathode), or the 'A' diode being the isolated diode and the 'B' diodes the (unequal) ones sharing the triode cathode. But I shan't be losing sleep over this...

It's a good system.

22nd Aug 2019, 6:05 pm	#10
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,088	Re: Valve Items - Philips/Mullard Rimlock-to-Noval Transition Yes, 'X' and 'Y' were used for 450mA and 600mA (can't remember which way round though). '7' as first figure is not always wire-ended, sometimes it is Loctal (eg EM71 - one wonders why this was not designated EM21?) And '5' existed as first figure, B9G (eg EF50). But it was not a common base, though the sheer quantity of EF50's produced rather made up for it! 'B' as second latter didn't always mean diodes sharing the same cathode, EB91 has for instance separate cathodes (there is also an EAA91!!). In the EABC80 it's a moot point whether the 'B' refers to the two FM diodes (one completely isolated, one sharing the triode cathode) and the 'A' the AM diode (which also shares the triode cathode), or the 'A' diode being the isolated diode and the 'B' diodes the (unequal) ones sharing the triode cathode. But I shan't be losing sleep over this... It's a good system.