[Hallicrafters] HA-1 issues...

[jeremy-ca]

Ken, I believe there are 2 versions of schematics. Its been awhile but a 
past experience with the HA-1 sort of jogged a few brain cells.

Carl
KM1H


----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon2006 at verizon.net>
To: <Hallicrafters at mailman.qth.net>
Sent: Wednesday, June 04, 2008 1:20 AM
Subject: [Hallicrafters] HA-1 issues...


>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
> ______________________________________________________________
>