[Hallicrafters] Loctal tube line up - whatzit

[Mike Everette]

In many AA5 radios the pilot lamp is connected across
a portion of the heater in the 35Z4 or 35Z5 rectifier.
 Look at the pin-out for the tube and you'll see three
pins for the heater; one of them is marked "dial lamp"
or some such.  And if the dial light is out, or if one
with the wrong current rating is used, the life of the
rectalfire is greatly shortened.

I've never worked on an S-38 (I'm not anxious to be
electrocuted) but I'd bet the dial lights are so
connected.

The older acey-deucey Hallis like the S-22/22R used a
ballast tube that provided series resistance for part
of the heater string,and the dial lights, rather than
connect the lamps across part of the rectifier
filament (besides the 25Z5s used in these sets don't
have tapped heaters....).  

ALWAYS use an isolation transformer when operating any
acey-deucey set, especially one with a metal cabinet! 
If you don't, you may find the Grim Reaper breathing
down your neck....

73

Mike
WA4DLF



__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com