[GreenKeys] Looking for TTY Signal Source

[Jim Haynes]

Well what I use is kinda funky, but...

There is an old IBM PC program out on the web named RTTY12G.  I have an 
old laptop computer with a COM port and a floppy drive (can also take a 
CDROM drive)  So I format a floppy to include the system files and that 
gives me a bare-bones DOS system.  I put the RTTY12G binary on the floppy 
and run it and it turns the PC into a "glass Baudot Teletype" with RS-232 
COM port.  Then these days you can use a solid state relay IC or a
suitable transistor to key the 60MA loop with the signal from the COM
port.  Solid state relay is preferable since it is opto-isolated.
I've also written the program to a CD ROM but the disadvantage to that
is that you have to write to the ROM at the same time any files you
might want to send.  Either way I've got a highly portable test set
for my machines.

Jim W6JVE

 	---

 	"Ya can argue all ya wanna, but it's dif'rent than it was."
 	"No it ain't! No it ain't!  But ya gotta know the territory."
 		Meredith Willson, The Music Man