[ARC5] 7V and 14V Tubes

[Mike Morrow]

Wayne wrote:

> Actually the Loctal Tubes with 7V and 14V filaments were indeed meant for
> 7V and 14V filament voltages...

Geoff wrote:

> Loktals are listed at 7 and 14V nominal in Sylvania listings and 6.3 and 
> 12.6 as acceptable. Sylvania was the developer.

AFAIK, only Sylvania claimed that loctal filaments were nominally rated for 7.0
or 14.0 volts, rather than 6.3 or 12.6 volts.  That is reflected in the 1951
Sylvania tube data manual.  But sometime before the publication of the 1959
Sylvania tube data manual, Sylvania appears to have abandoned this pretense.

See these documents at http://www.tubebooks.org/sylvania_tube_manuals_online.htm

A claim that loctals used 6.3 and 12.6 volt filaments seems to be the position
that is best supported by even Sylvania's own manuals, at least by 1959.

Not that it ever made much difference!

73,
Mike / KK5F