[GreenKeys] Fwd: Current Loop

[Teletypeparts at aol.com]

Hey Guys, 
 
I am forwarding a message I got from Tom Lake who has a 33 he got from  me. 
 Can anybody help him with the problem he is having hooking up the 33  to 
his Altair?  The 33 is wired for full duplex (4 wire) and he can make  the 33 
receive work OK, but I am not familiar with the Altair hook up as he  
describes it.  
 
Thanks,
 
Wayne
KB1FDW


From: thomas.lake at srmt-nsn.gov
To:  Teletypeparts at aol.com
Sent: 7/20/2009 2:04:56 P.M. Eastern Standard  Time
Subj: Current Loop


Hi, Wayne!

Remember me?  I  bough a Teletype from you a while back.

It's still working fine with my  PC but now I'd like to use it with
my old Altair 2SIO serial interface board  which is supposed to handle
20 mA Current Loop OK.  The problem is the  teletype prints from the 
computer
but won't input to the computer.  I  know the TTY is good because, as I 
said,
I can use it with my computer with  no problem for input and output.
Is this a problem with active/passive  loops?  Is there a way to change the 
TTY
to allow one or the other  on both TX and RX?  I don't see a way to change 
the
2SIO board to do  that so I'd like to adjust the TTY if possible.
Do you have any other  ideas?

Thanks for any help you may be able to give.

Tom Lake
 
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