[GreenKeys] LAPR questions

[John, W9DDD]

I inherited a LARP years ago.  It appeared to have been a miniaturized 
version missing cover and tape winder.
http://www.navy-radio.com/manuals/tty/sales/larp.pdf
The previous owner mounted it in a rack mount shelf and modified the 
wiring but kept the tape supply container and at least part of the base 
plate.  Wiring has been changed to connect to a solid state driver board 
of some kind mounted on the same shelf.

A chance to capture an auxiliary reperforator (dome mounted) fell 
through and it went to the land fill.

I read that the Delta system used a LAPR on a ASR keyboard, not 
interested in that modification.

At some point I saw a reference to the use of a LAPR as an auxiliary 
reperforator.  Found in the LARB parts section reference to an auxiliary 
base for the LARP which appears to work the same way as the LPR 
auxiliary base.

I did some searching of the greenkeys archives and see that the Plan 55 
system did use a dome mount LAPR.

I found Page 5 of:
http://www.navy-radio.com/manuals/tty/573-144-800-7012.pdf
One difference was the posts (studs) for mounting the base to the LCXD 
and rails had different part numbers from those for the more common dome 
mounted typing reperforator.

A FTGH LARB5 showed up on my doorstep along with a set of studs 
presumably for the more standard dome mount which were shorter.  A 
little threaded rod can fix that, right?

Not so fast.  The holes in the LARB don't line up with where I thought 
the studs should screw in.  The front stud seems to be in a reasonable 
spot, but the rear pair are way too close together.

Was there a specification or SOP that had them drill and tap difference 
holes in the read rail?

If I can whip the mechanical issues, the plan is take an Arduino to 
drive (not directly of course) the magnets with the ability to accept 
serial 60/75/100 input or text from the pc via the USB port of the 
Arduino.


-- 
John, W9DDD