[GreenKeys] Silent 700 Terminal with a 43 TTY (TDU) ?

Wed Apr 10 16:57:07 EDT 2013

Chris' description of the "originate" modem setup kicked loose an old Dust Bunny of a memory. We used to have to connect leased line modems together (at 1800 baud) to test our equipment in order to determine if comm problems were internal or external. One FE had a "Ma Bell" cable, complete with D-blocks, that would cross connect the modems. We would be monitor the RS-232 signals to verify everything was working.
Could you use a similar setup to connect the Silent 700 to the model 43?  If needed you could run the signals through an isolating interface using an opto-isolater chip to avoid voltage level conflicts. We used to connect TD-830 data terminals to loop current driven dot matrix printers the same way (the isolator circuit was built into the printer), and never had a problem.

Mike - N9ODM

ASCII and ye shall receive.

________________________________
 From: Chris Elmquist <chrise at pobox.com>
To: greenkeys at mailman.qth.net 
Sent: Wednesday, April 10, 2013 12:25 PM
Subject: Re: [GreenKeys] Silent 700 Terminal with a 43 TTY (TDU) ?

Yes... roger that.  I keep a couple TI Silent 700's running and indeed
you can get "thermal fax paper" at most office supply stores.  The rolls
are smaller (ie, less paper) than OEM but it is the same kind of paper
and works well.

As for connecting a model 43 to a Silent 700 using the "phone plug",
I think you might have trouble.   If it is a phone plug for connecting
to the telephone network, then it's very likely that it has an internal
"originate" modem with DAA in it.  The Silent 700 might have an acoustic
coupler too and that would also be an originate modem.

These two modems won't talk to each other because they are both using
originate tones.  You need an answer mode modem to accept the call from
the terminal(s) and use the opposite tone pairs for each direction not
to mention getting from the acoustic coupler on one to the direct connect
modem on the other.

Your best hope would be to find the serial data on some connector or
port before it goes to the modem.  I am not aware of any Silent 700 that
had 20mA and all those I ever saw were RS232.   So, if you can find an
RS232 connection on the M43 and also on the '700, this would be the way
to connect them together.

My 725 and 745 models do 110, 150 and 300 baud...  7 bits, selectable
even/odd parity and I would guess the M43 can be set to match one or
all of these modes as well and then you should just need three wires--
Tx, Rx and GND to hook them together...  but I realize there's a lot of
handwaving and what-if there since we don't know much about the interface
capabilities of either machine.

Chris N0JCF

On Tuesday (04/09/2013 at 08:30PM -0500), Sherry Guttery wrote:
> On 4/9/2013 5:56 PM, Richard Schumann wrote:
> >Wow...can you still get thermal paper to fit those?
> I am not sure if your looking for 98' roll of Thermal paper, but if
> the kind and size you need is 8.5" x 98' x 1/2" core it can still be
> ordered from Staples or similar approximately $18.99 for a 6 pack.
> >
> >    ----- Original Message -----
> >    *From:* Norm <mailto:normand3 at q.com>
> >    *To:* greenkeys at mailman.qth.net
> >    <mailto:greenkeys at mailman.qth.net>
> >    *Sent:* Tuesday, April 09, 2013 1:49 PM
> >    *Subject:* [GreenKeys] Silent 700 Terminal with a 43
> >    TTY (TDU) ?
> >
> >    Hi
> >    The Question today for me, will a Silent 700 Terminal
> >    work back to back with a  model 43 TTY equipt with
> >    aTerminal Data Unit (TDU)  that has the phone plug?
> >    Thanks
> >    Norm
> >    WB7WEQ
> >
> >
> >
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> 
> -- 
> sherry guttery
> 
> A Tender Tale - a page dedicated to those Ships and Crews
> so vital to the United States Silent Service: In Memoriam / Randy Guttery
> http://tendertale.com
> 
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-- 
Chris Elmquist

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