[GreenKeys] 28ASR questions

[Don Robert House]

I sincerely hope this machine does not get cobbled up for RTTY.  It  
is an artifact that needs to be preserved.
I stand by my offer of a private line ASR in trade.

Don
K9TTY


On 19 Apr 2006, at 7:48 PM, WA3FRP at aol.com wrote:

> 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
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