[GreenKeys] Need PC to TTY Loop Keyer ASAP fast

[Don Robert House]

Not sure about 20 mils at the line cord.  When we helped film FOG OF  
WAR both model 32s were former TELEX machines.  Neither had their own  
power supply, except for the off normal dial supply.  I ran both line  
cords in series with a Navy surplus rectifier set at 60 milliamps.   
Maybe just my ignorance of TELEX machines but the 32ASRs both ran  
just fine.

Don


On 4 Oct 2005, at 10:29 AM, gil smith wrote:

Hi John:

I just replied to Sellam -- didn't know it was the same project.

The TTY-Connect unit does NOT work with an externally-powered loop,  
since it has a built-in supply.

However, my old TTY-232-TAP gizmo does.  It also derives interface  
power from the 232 port, so read the notes to ensure that your port  
can be configured to set the needed lines appropriately.

The schematic is at:
http://www.baudot.net/gil/tty232-tap/TTY232_TAP.pdf
and the rest of the poop is at:
http://www.baudot.net/gil/tty232-tap/

The TAP can be set for a 20-mA loop, which is what I presume the M32  
needs, and it has a bridge so you don't have to worry about loop  
polarity..

I can loan you mine (I only have one TAP built up), if I can find  
it.  I'll make sure it is configured for 20-mA and overnight it to you.

However, this is also presuming that your computer has a serial port  
that supports 5-bit mode (like most desktops).  You mentioned a  
laptop -- if you have been following the discussion of USB-to-232  
adapters, I hope you realize that they will likely not work for an  
app like HeavyMetal.

If you are stuck with a laptop, an ascii-only USB adaptor, and  
therefore cannot use the TAP device, my only other suggestion would  
be to use a modified TTY-Connect that patches-out the low-voltage  
loop supply, to allow connection to an externally-powered loop.  I  
can probably do that for you as well, but you need to let me know, as  
my day is already hectic.

If you go this approach, the ascii-to-baudot conversion will be  
provided by the TTY-Connect, and the pc will talk to it in ascii mode  
at 38400-baud.  This means you cannot use HeavyMetal (which talks  
baudot), as your pc needs to send ascii to the port.  You can simply  
use a terminal emulator (eg: HyperTerminal), and then just use the  
text-file-transfer option.

let me know,

gil


At 07:52 AM 10/4/2005, you wrote:



>   Further to yesterday's post re: making an ASR23 operate  
> 'normally' for a movie shoot in NY (Brooklyn) - is there anyone  
> within the sound of my keyboard who would be able to offer a  
> suitable interface (Sale, loan, trade, gift...) that would allow a  
> PC, most likely a laptop, running HeavyMetal - to key the loop of  
> the Mod 32?  A loop supply is with the machine, and has a dropping  
> resistor for the correct current - we just need the laptop to speak  
> to the TTY. Perhaps someone has a nice TTYConnect of Gil's that  
> they could do without for a week or so....  or any other RS-232 to  
> current loop keyer....
>
>
>   And, (of course) this needs to be in New York and working  
> tomorrow sometime.
>
>
>   Anyone who might be able to be of (compensated!) assistance,  
> please write directly to Sellam, vcf at siconic.com ,  or myself - off- 
> list please.
>
>   Thanks!
>
>  Cheers
>
> John   KB6SCO
> _______________________________________________
> GreenKeys mailing list
> GreenKeys at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/greenkeys
>
>



Vaux Electronics, Inc.
480-354-5556
(fax: 480-354-5558)
www.vauxelectronics.com



_______________________________________________
GreenKeys mailing list
GreenKeys at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/greenkeys