[ARC5] Loctal Tubes

[Bill Cromwell]

Hi,

I have accumulated and started using some of the loctal tubes in
projects I intend to accommodate field use. There have been some
comments about them that I would like to address.

Loctal tubes are difficult to remove from the socket. Loctal tubes have
a raised spot on one side. We are supposed to apply sideways pressure
and slightly tip the tune from that side to UNlock them from the locking
ring in the socket. That's why we call them LOCtals. They won't fall
out.

Some oxidation products get on the pins and cause intermittent
connection failures. That is the same as for miniature tubes that have
the same kind of pins. They need periodic maintenance to keep the
contacts cleaned up. The occasional cleaning applies to loctals and
miniature tubes. I have experienced the same thing with octal tubes,
too. There doesn't seem to be a free lunch there.

Voltage levels like everything else vary within specified limits. 6 volt
and 12 volt and 24 volt automotive (or aircraft) battery systems are
only rarely at 6.000000000000000 or 12.0000000000000 or 24.0000000000000
volts. Fully charged batteries vary and are closer to 7 or 14 or 28
volts. The charging systems are necessarily higher. The published heater
ratings I've seen are the same 6.3/12.6 volts as many other tubes. I
haven't seen the tube manual that specs loctals at 7 or 14 volts. I
haven't seen the Taj Mahal either but I believe it exists. Given the
allowable variation in those battery electrical systems 6.3/12.6 would
include 7/14 volts.

73,

Bill  KU8H