[GreenKeys] speaking of the ST6 [was ST6 questions]

[John Becker]

There was 3 ST-6's built in the lab at McDonnell Douglas Aircraft in St Louis
Tuned with the best equipment taxpayer money could buy that I would say
was 100% right. and talk about being tight. You really had to pull out the
stops to copy these 200 Hz shift TNC's. All 3 had the XTK100 crystal controlled
AFSK board in them. They would be easy to spot. All the wiring was laced up
with flat black lacing used on the F4 fighter. And should have a stamp with
the numbers of 177146 on the inside bottom between 2 of the boards near
the center.

I still have 1 of the 3 units built about 1976 or 1977. I have no idea 
where the
other 2 units are today. Joe, K0BX may know.

John, W0JAB


At 05:51 PM 7/16/2006, Don and Diana Cunningham wrote:
>Eugene,
>I'll take a stab at some of these.  For copying RTTY, the shift is the 
>most important of these variables, as you won't know the difference when 
>you tune the signal in properly.  ST6 #1 is very close, and probably would 
>work fine. Where you could run into trouble is on transmit where your 
>transmitted tones should match.  You will always be off frequency to those 
>that copy you just a little, but likely no one would notice except a few 
>of the "particular" gentlemen that notice such things, hi.  It is not hard 
>to tune the toroid filters to put them very close on to the 2125/2295 pair 
>that is common.  I think someone posted the tuning info that Irv Hoff, 
>W6FFC, put out in a QST article a few weeks ago.  I think he might have 
>posted that to RTTY.com, but not sure.  I might be able to find a copy of 
>that if you needed it.  His method is very easy, and if you remove turns 
>from the toroid, you can learn to get VERY close to perfect tone pairs on 
>the ST-6.  Wiring errors are VERY common on kit ST-6's.  I have RARELY 
>found one that was perfect, hi.  I don't remember what the autoprint 
>transistor was, but there could be two different basings very 
>easily.  Good luck with your TU's.  The ST-6 was one of the best!!
>73,
>Don, WB5HAK