[Hallicrafters] HA-1 issues...

[Kenneth G. Gordon]

I have an ancient Hallicrafters T.O. Keyer, HA-1 which has 
been giving me fits lately.

First of all, I think there is an error in the manual (from 
BAMA) on page 12, section 7-4, which is the  voltage table 
for the various tubes.

>From what I can tell in the circuit, the voltage at pin 1 of V-
2, listed as 1 volt in the table, should actually be +10 volts 
instead.

There is -10 volts on pin 7, which is on the other side of the 
balance pot.

If someone would be so kind as to verify, or not, my 
suspicion, I would be grateful.

Pins 1, 2, and 3 of V-1 are around 20 to 30 volts low,  but 
that COULD be due to out-of-tolerance resistors, or a gassy 
tube drawing too much current. 

The chart does tell me that voltages can vary +/- 20% from 
those listed, but 10 volts is a heck of a lot more than 20% 
different from 1 volt.

BTW, ALL of the tubes in my HA-1 are labeled 
Hallicrafters, so I think they are original.

A second possible error is that voltage listed in the table for 
pin 6 of V-4 is incorrect. The table lists this voltage as +150 
VDC, but if the schematic is closely examined, there is NO 
WAY this could be 150 volts. Mine measures +214 VDC, 
and this seems more reasonable to me.

Although (after replacing two capacitors, and one diode) 
the keyer seems to work acceptably, the neon bulb on the 
front panel, which is SUPPOSED to blink twice for every 
dash, and once for every dot, doesn't work at all now, but 
DID work for several hours a couple of days ago, and that 
has me baffled. 

I suppose it COULD be a failed NE-51, but the bulb sure 
isn't discolored...just dark.

Anyone have any ideas?

Ken Gordon W7EKB