Is there a document that lists all the different M28
reperf "LPR" models and what is different about each?
I'm working on a TT-253A (thanks to Nick!) that does not have a
standard reperf in it. The TT-253A is supposed to use a LPR53AWA
(full perf, tape feed out, backspace). What is in this unit is a
LPR13XXX (chadless, tape feed out, no backspace). The unit punches
fine (after I re-hooked up a spring in the Selector Magnet area),
but can't check the printing yet due to missing print hammer (one
on order from Nick).
In checking out the "Tape feed-out" function - the tape feed-out
solenoid operates (and buzzes) and the ratchets turn but no tape
out. I think this is the version that tape-out is suppressed by
incoming message (there is an arm going up towards the SM
armature), but can't see why it is not releasing the function
clutch when running closed.
Also confusion between different manuals about whether the tape
feed-out solenoid is supposed to operate on 115V AC or 115V DC.
1963 vintage manuals (eg NAVSHIPS 94456) show TT-253A using
LPR53AWA reperf with solenoid L5850 (TC # 274); 450 ohms; 115VDC.
Wiring diagrams show the LTRK5 base with a series resistor &
diode and parallel capacitor to supply the 115VDC. But this LTRK5
base has the resistor & diode replaced by wires and the
capacitor removed.
I thought that the removal of the 115VDC parts could have been a
later modification. (Besides the change of LPR unit, this TT-253A
had the power & signal lines soldered directly to the blue
Amphenol 16 contact ribbon connector!) (I've ordered the mating
connector)
Then I got a hold of the NAVELEX 0967-LP-616-7010 (APR 79) manuals
and they show the LTRK5 base and LPR53 wired for 115VAC!!
I'm getting confused!
The reperf in this TT-253A is a LPR13XXX, with a tape-out solenoid
#252 and measures 200 ohms and it does not look like any of the
drawings in any of the manuals. (Pictures enclosed) I've read how
the tape-out mechanism is supposed to work, but had trouble
following it, especially in that my unit seems different from what
the manuals are talking about.
When I energize the solenoid, the timing ratchets rotate, but
nothing else happens. I've tried pushing & pulling (gently)
the various levers in the area, but nothing trips the function
clutch. I'll put in the parts to put DC on the #252 solenoid, but
I don't think it will affect the tape-out.
This dissertation was partly just to get my thoughts & facts
together, but if anyone has any ideas about the tape-out
mechanism, I'd like to hear them.
Thanks,
Duncan
K2OEQ