Hi Duncan: Teletype called their standard 1/20th hp, 3600 RPM motor the LMU3. The
Bell System called the same motor a 28A. No difference at all. The motor leads on the
LMU3 were adequate for almost all installations. The most notable exception was the
dome mounted auxiliary reperf used in M28 ASR sets. The motor leads had to be fished
out of their normal exit hole in the motor cradle and re-routed in such a fashion so that they
would barely make it to the terminals on the base. Just adding some additional length to
the motor leads should solve the problem.
Regards, Jerry Murphy
From: Duncan Brown <[email protected]>
Sent: Jul 27, 2022 9:58 AM
To: Green Keys <[email protected]>
Subject: [GreenKeys] M28 motor for LXDB3 tape reader
I have a M28 stand alone tape reader (thanks, Bruce), LXD7 on LXDB3 base (with label TT-423/TSC-23) that I am checking out.
It looks like the motor has been changed out, as the motor power wires (with spade lugs) are at least 2-3" too short to reach the power terminal strip. The motor does run. The only ID on the motor bracket is " Motor unit 28A". The motor casing says "Teletype Corp." on it and "Motor No. 5SC18L08", which doesn't sound like a normal Teletype corp. number. (motor manufactured by GE)
I can't find anything that tells me what motor should be in this unit. The parts bulletin for the LXDB (1161B) just says "for Motors refer to Bulletin 295B". But 295B does not mention the LXDB base. Just that the LMU3 is the standard motor. Did all LMU3s have the same wire length?
Its not a problem to extend the existing motor leads, just wondering why the leads are not long enough and/or do I have the wrong motor for this unit.
This unit has undergone some mods as the external wiring (signal and two remote control lines) was all done with zip cord. Also, the is a SPDT relay in the base that gives external control of the motor and it is also wired with the same zip cord.
If this is the correct motor, why is the cabling too short?
Thanks,
Duncan
K2OEQ