[ARC5] Loctals in Type 12 Receivers

[Robert Eleazer]

Loctals were of course somewhat less likely to fall out of their sockets than octal tubes (anyone who has ever cursed while trying to get one out could see why).  And rated at 14V were supposedly more suitable for mobile and aircraft 14V/28V DC power systems than 6V and 12V tubes.

I would guess that the Loctals were considered "The Next Thing" after the octals and could use a very similar chassis to the WWII sets.  Note that the BC-620 and BC-659 of WWII used loctals, although not the same ones as the Type 12's, as did some of the BC-1206 sets.   

But as for why they were used in the R-15 and R-19, I think it is because the R-11A and the BC band sets used exactly the same tubes in the IF.  Easier to design and easier to maintain, commonality in service and probably interchangeable chassis during manufacture.

Interesting that the WWII version of the APR-4 used octals in the IF and acorn tubes in the tuners.  The 1951 version, APR-4Y, used miniature tubes.   

Wayne