[Hallicrafters] Technical questions:

[Gerry Steffens]

Hi Skip,  Its been a while.

While I am not at home to check, it sounds like the connection for a 0A2
voltage regulator, although the 135 volts seems too low.  S/B a kick in
voltage around 155 and regulating to about 150 volts as I remember.  A 0B2
has the same connections but kicks in at 115 volts and regulates to 105
volts up to 30 ma if memory serves me (this one I have checked recently).

Gerry


-----Original Message-----
From: hallicrafters-bounces at mailman.qth.net
[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Waldo Magnuson
Sent: Saturday, May 24, 2008 9:50 AM
To: hallicrafters at mailman.qth.net
Cc: Waldo Magnuson
Subject: [Hallicrafters] Technical questions:

Carl (KM1H) said:
Sometimes a little change of pace wakes up a usually dull and dead 
forum.
Im rather surprised that there are so few threads of a technical nature.

So here is a technical question of sorts:  I have a simple power supply 
which has a tube between the output of a 4 diode bridge and the B+ to 
the equipment.  I can not read the tube type on the glass (it's been 
polished off).  The diode bridge connects to pin 1, pin 2 goes to 
ground through a 2.2K, 2W resistor.  pin 5 goes to the output (135 
volts).  No other connections - it is a 9 pin (or 7 pin - I'd have to 
look again) miniature tube.  I would like to know what type of tube it 
is for drawing the schematic.  How do I identify it?  Is there a visual 
tube expert out there that if I sent a close-up picture it could be 
identified from the structure?  I suspect it is a ballast tube but I'm 
not sure.

73,  Skip W7WGM

______________________________________________________________