[GreenKeys] Hal ST-6

[Bill Henry]

Wayne,

Is your 32 loop plug a "mono" plug (2-terminal), "stereo" plug 
(3-terminal), or 6-pin Molex?  Very early HAL ST-6's had mono loop jacks - 
and also had an insulated washer on the rear panel mounting.  If the ST-6 
has a mono jack, the loop wires go to "tip" and "sleeve" terminals of a 
mono plug.  Later ST-6's had a stereo loop jack with no insulating 
washer.  If it's a stereo jack, the loop wires go to "tip and ring" 
terminals - and no connection to the sleeve terminal of a stereo plug.  The 
last ST-6's (late 70's) had a Molex loop connector like that used on your 
ST-5000.  Connecting the printer loop wires to pins 1 and 4 should work for 
both modems.  A steady Mark light with no M/S flicker probably indicates 
that the keyer transistor (Q305) output is shorted to ground - either a 
blown 2N5655 (MJE-340) or a wire is hooked to the wrong place.

Bill Henry


At 03:31 PM 5/21/2008 -0400, Teletypeparts at aol.com wrote:
>I have a Hal ST-6 that I picked up from WA2HWJ.  It worked when he last used
>it.  I hooked it up to an after-market Telex and blew the loop switching
>transistor (The after-market 32 is gone now).  After replacing the keying
>transistor in the ST-6, it seems to work OK, but when I plug in my 32 
>teletype into the
>printer jack, the mark and space lights stop blinking and the mark light is
>on steady.  No printing on the 32.  This 32 works fine in my Hal 
>ST-5000.  Any
>ideas on what is going on?  Above testing was done with W1AW bulletin tuned
>in.
>
>I dont really need this ST-6, so if anyone is interested buying it (working
>or not working as described above), any offer would be considered.  It is 
>very
>clean inside and out and comes with the manual.
>
>Thanks,
>
>Wayne
>KB1FDW
>
>
>
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