[Hallicrafters]V16#16 - HA-1 Schematic

[Phil Barnes-Roberts]

At 09:23 PM 5/6/05 -0400, hallicrafters-request at mailman.qth.net juggled the 
keys to produce...
{snip}
From: "Murray Grandy" <mgrandy at telus.net>
>Precedence: list
>Subject: [Hallicrafters] need help with Hallicrafters HA-1 code osc.
>Cc:
>Date: Fri, 6 May 2005 17:00:06 -0700
>To: "HALLICRAFTERS" <Hallicrafters at mailman.qth.net>
{snip}
>Could someone who has the schematic for the HA-1, please take a look at 
>the top lead from the secondary of the output xfmr and see if their's is 
>the same as mine. This lead seems to go to an open contact on the K1 
>relay. I think my HA-1 has been modified and I can not trace the wiring 
>properly. Is there a wiring diagram for it. Would love to get this unit 
>working properly.
>TIA Murray

Well, Murray--
The HA-1 isn't just a code practice oscillator, it is a commercial instance 
of the venerable W9TO Keyer, with tube flip-flop multivibrator circuits (3 
of the 12AU7's, dual triodes.)  My schematic/manual, just downloaded from 
the BAMA, shows just that, T2-sec to K1-2, where K1-3 grounds it on make, 
thereby allowing the V4B sidetone oscillator to be heard while your 
transmitter is keyed by the other contacts through SO-1 (the other octal 
socket, on the back panel.)  Notice, that socket also has contacts for your 
keyer paddles, parallel to the stereo-style phone jack on the front 
panel.  Tip is dots, ring is dashes, shell is return/gnd.

I would suggest using a Web browser, going to < http://www.bama.sbc.edu > 
and downloading the manual; print it and read through it before heating up 
the VOM or VTVM to try the thing out.  You'll need the DejaVu plug-in for 
the browser, BAMA shows you a link to go get it.  I had to install it for 
IE6 first, then copy it over to Netscape's plug-in folder, and it works 
with the new Mozilla Firefox as well.

Now if somebody had a _really_clean_ copy of the original W9TO docs I could 
share with Lynn for his N7CFO Keyletter - or even better, the ones for the 
W9UE kit version, the "Auto-Mate K5/50" - we have a dead one to work on 
here... so I don't have to fire up OrCAD to make one.
73, Phil Barnes-Roberts WA6DZS  DM04we | Mailto:wa6dzs at arrl dot net
The only Dumb Question is the one you Didn't Ask because you thought
it would Sound Dumb.  --AQF1 Jones