"Cont58" wrote in message
...
I have a TH-5/TG and I will like to know the
year this unit was built and any info where this
unit was use.

Thanks,

Pierre VE2MP

GIYF: from http://hereford.ampr.org/millist/m24.html

TH-5/TG
"Telegraph terminal, Frequency-shift keying, Used with standard tetetype
machines, Vacuum tube based, Mark 1325 Hz, Space 1225 Hz, 20 Ma loop,
Maximum speed 100 WPM (75 Baud), 115 VAC, 50-60 Hz, 65 W, Worked with 4-wire
(full duplex) or 2-wire (half duplex) circuits, 15 Lbs, TM 11-5805-246-10. "

In other words, it's a modem, with non-standard tones and 100 Hz shift,
probably intended for use on radio as well as landlines. The 20 Ma current
loop is low for older Teletypes, which (IIRC) usually use 60 Ma loops
connected directly to the selector magnets, but it's useable for the Model
32/33 machines, which have built-in driver transistors to amplify the loop
current. Since the maximum speed is listed at "100 WPM (75 Baud)", it was
used for older (Model 15 or 28) machines, where 100 WPM is possible with a
75 Baud transmission rate.

To use it with a computer, you'd need an RS-232/Current loop convertor: they
were common in the early (PDP-8) days of computers, since Model 33's were
the least-cost terminal available at the time. Of course, the Model 15/28/32
machines would require a custom driver to convert Baudot to ASCII.

If you only have one of them, I suggest a museum: I don't think the current
crop of units available to Ham operators will work at 100 Hz shift, but I
don't know for sure. With a pair, you could construct a low-speed link.

HTH.

Bill

(Filter noise from my address for direct replies)