I realized after I sent the email that the motor governor might
not have sufficient range, but it was worth a try!
I will look and see what I have in the way of 50 baud gears on
Tuesday.
73 & have fun
Duncan
K2OEQ
On 3/8/2026 5:49 PM, Dale Hughes via
GreenKeys wrote:
Hi Duncan,
Hello from Canberra, Australia!
I would also be interested in a set of the 50 baud gears if
they're available. I also have a TT4C machine which only has
45.5 and 75 baud gears. I have tried to adjust the motor speed
to change the machine speed up to 50 baud from 45 baud but I
found the governor didn't have enough range. Attached is a
photo of my setup.
73
Dale Hughes VK1DSH
On Mon, 9 Mar 2026 at 04:14,
Duncan Brown <[email protected]>
wrote:
Pete,
I will check our stock at the AWA (Antique Wireless
Association - not to be confused with Amalgamated
Wireless Australia) Museum when I am there on Tuesday. I
know I have extra gears, but don't know offhand if there
are any 404 opm gears.
All mechanical TTY machines can receive over a +/- 10%
speed variation, using the Range Control to adjust when
the selector magnet reads the data. So your TT-4 can copy
66wpm with the 368 opm gears (just turn the Range control
down to about 20), but of course you will need the 404 opm
gears to transmit 66 wpm.
You could also try increasing the motor speed by about 10%
while still using the 368 opm gears. I don't know how
increased speed would affect the life of the motor or
brushes. But since the unit was designed to work 24/7,
and as long as you only use it a few hours a day, I
wouldn't think it would affect its life significantly.
Good luck & have fun,
Duncan Brown, K2OEQ
USASA 31J30
Antique Wireless Association
Communication Technologies Museum
Asst. Curator, Commercial Equipment
(also chief TTY op & repairman)
I need a gearset for a TT-4/TG to operate at 404 OPM /
66WPM / 50 baud. I am happy to exchange a 368.1 OPM / 60
WPM / 45.45 baud set and a 600 OPM / 100 WPM set. The
TT-4 manual states that the 368.1 OPM set is normally
fitted and the 404 OPM set is held inside the machine.
My machine is fitted with a 368.1 OPM set holds a 600
OPM set.
I am located in Adelaide Australia and am happy to pay
parcel post both ways.