[GreenKeys] 28ASR questions

[WA3FRP at aol.com]

>this is a WU machine, originally connected to a phone line, which I  
>suppose makes it a TWX machine.  I have not heard of TWX 28ASRs --  I 
>presume that there is a dataset (modem) sitting in the base somewhere,  
>which I would guess connects to the machine loop interface on a terminal  
>block somewhere.  Does anyone have any knowledge of the TWX  version?  How 
>would one go about disconnecting the dataset to allow  normal loop 
>operation?  Can you point Fred to specific locations on  a terminal block 
>for this?

There was a "three row" TWX service that AT&T ran for  years that was 
purchased by Western Union in the late 1970s.  Since this is  a WU machine, it also 
may have been used for Private Line Service and also  connected to a phone 
line.  If it's a TWX machine, the dataset should be  inside the base. There are so 
many variations of WU machines that  Fred may have to need an ohm-meter and 
play detective.  It may be  helpful to look at the Model 28 ASR electrical 
diagrams on the www dot rtty dot  com website.  They aren't WU wiring diagrams but 
they are probably  close.  
 
>there is a test switch of some sort, which, in one position allows the  
>machine to run open, and in the other position quiets it down, but he  
>cannot type, presumably the keyboard is isolated form the selector  magnets 
>for full-duplex  use.

Yes, WU had a test switch that would shunt the loop toward the central  
office for line testing.  This switch may also lock up the selector  magnets.
 
>on the typing reperf, he asked me a simple question: how to load the  
>tape.  I have several sitting around here, but I have never used  one.  I 
>tried to feed a bit of tape down the chute but was unable  to get it to feed 
>through.  What's the trick on this?  I need  to dig through some boxes to 
>find some buried ASR docs.
 
It helps if you cut the end of the tape at a diagonal with a scissors. It  
also takes a little practice.  Slide the tape as far as it will go without  
bunching up. Then start the typing reperf.  Put a slight amount of  pressure on 
the paper tape and it should start to feed up and through the  punch.  Sometime, 
you have to carefully guide the tape into the  punch.  Other times, it just 
seems to find its own  way.  Practice, practice, practice...
 
>Also, Fred wishes to get a radio/tu setup running, and he wanted to  know 
>more about the 14 MC stuff that has been going on -- what's the  update on 
>that?  And by the way, where is everyone located?   I'm thinking you are all 
>on the east coast -- here in AZ I have not been  able to pick any of you up, 
>but Fred is in WI and may have a better  chance.


Selecting a receiver - you could write a book on that subject alone.   Get 
something stable that has the ability to receive CW.  There are lots of  ham 
band only receivers available at reasonable prices or top of the line  general 
coverage receivers, like the Collins R390 series that weigh 75  pounds but will 
lighten your wallet. The same is true for the TU.  A  nice ST-6 is a great 
start, but there are lots of variations. 
 
The Autostart net is currently operating sporadically on 14.0841  MHz.   The 
folks who check in most frequently are Tony in California  (W6ESE), John in 
British Columbia (VE7BDQ) and me in  Pennsylvania. 
 
 
I hope that this helps and that others jump in with their comments as  well.
 
73
Russ
WA3FRP