[Michael Dennis]

I'm wondering if anyone can tell me why Philco used certain tubes in some of their radios, specifically, why, for example, in some 1942 models for a nine tube circuit, was there a mixture of an octal, (5Y4G), two sixpin tubes, (type 41), and the remaining being Loctals, or "Loktal" tubes as Philco called them? Wasn't the type 41 by then largely replaced by octal types? I don't know if it had to do with industrial rivalry, marketing of the "Loktal", or to avoid paying license for certain types. Anyone got a clue?

[codefox1]

Probably World War 2 had something to do with it. So they used what they had on hand, or could get.

[Michael Dennis]

Hmmm, maybe so, but this particular set I had in mind was available, as a 1942 model, in dealer showrooms by about August 1941. Maybe they could see what was coming and the "shortage" had already begun before we actually got involved December 7 1941.

[Alan Douglas]

Perhaps National Union had a production line already set up for 41s, so those were cheaper than 6K6s produced by someone else. Or Philco wanted to give NU the business (Philco purchased a controlling interest in NU in 1940).

No factory made every tube; whichever one was geared up for a particular type at the time would make them for any other maker who needed them, with the other maker's logo.

[Michael Dennis]

Thank you, guys. Something to think about. Don't have a tube manual handy right now; I assume the 6K6 replaced the type 41? I had just wondered why so many different tube basings in the same radio. The type 5Y4G is apparently a little older than I had first imagined; after all, some 1938 Zeniths used it before switching to the dreaded 6X5.

[Arran]

I think what others have said probably explains it, they lined up a deal on a rail car full of type 41s and chose those rather then a pair of 7A5s or a pair of 6K6s. Interesting that your set uses a 5Y4 with a pair of 41s, many early 40s Philcos used type 84s, 80s, and 7A4s. I saw a Canadian market Philco Bakelite model that was AC, not AC/DC, that used 2.5 volt tubes like a 58s and a 2A5, and it was from the early 40's, obviously they designed the set around the parts.
Best Regards
Arran

[Ron Ramirez]

I saw a Canadian market Philco Bakelite model that was AC, not AC/DC, that used 2.5 volt tubes like a 58s and a 2A5, and it was from the early 40's, obviously they designed the set around the parts.

Really? Which model was that? Very interesting...Philco never used those tubes in USA models.

[Arran]

I saw a Canadian market Philco Bakelite model that was AC, not AC/DC, that used 2.5 volt tubes like a 58s and a 2A5, and it was from the early 40's, obviously they designed the set around the parts.

Really? Which model was that? Very interesting...Philco never used those tubes in USA models.

I could ask the fellow who owned it, I haven't phoned him in about a year, my Canadian Philco manual ends in 1939 or so.
Best Regards
Arran

[Alan Douglas]

58s and 2A5s could have been available from stock, when more modern tubes were reserved for military equipment.

[Arran]

58s and 2A5s could have been available from stock, when more modern tubes were reserved for military equipment.

It's possible but at the same time they were making large consoles, like the Canadian versions of the 216, 316, etc., that used the more modern loctals and octals. I should see if the set my friend had is in the Radio College of Canada manuals to find out the year, my guess is it's from around 1940-41.
Best Regards
Arran

[Michael Dennis]

Interesting that your set uses a 5Y4 with a pair of 41s, many early 40s Philcos used type 84s, 80s, and 7A4s.

Yes, that's what I thought, curious mixture of an octal, (2) six pin and (6) loctals. Were radios being supplied with the tubes by then? I have a Philco 610 that uses a type 84 rectifier with a type 42 final audio, but since I had the 1942 Philco long before, I thought the type 84 was unusual, never having seen one before.