[GreenKeys] BRPE Restoration

Sun Dec 31 07:01:58 EST 2023

I was lucky enough(?) to acquire a BRPE21 on eBay.  Some pics at:
https://www.ebay.com/itm/335180419867

It arrived yesterday and "now comes the fun part" :->.  Overall it's in
pretty good shape, as seen in the pics, however two pins are stuck and some
others are sticky.  Not too surprising but I'm enthusiastic about having to
disassemble this unit down to the punch-block and then getting it back to
operational order.  So I'm very interested in hearing from anyone
maintaining a similar unit.  The vital information:

Base unit is BRPEB11 (side plate by power switch).

Punch unit is BRPE21 (8 level with three suppression switches).

Motor unit is LMU6 (plate on motor mount).

Motor plate states: 5PA66HV2A / Type: PA / V: 115 / CY: 60/50 / WD: SERIES

Base unit includes 9x top-hat diodes and 9x 25 ohm power (wire-wound?)
resistors.  Signal connector is a 24-pin CINCH 57-40240 female with cable
retention clips.  Example: https://www.ebay.com/itm/394787953341  The
connector is mounted in a wider cutout (but same end-to-end mounting points)
so presumably there were alternative connectors in use.  Includes cable
retention clips.  Example: https://www.ebay.com/itm/394787953341  Power
connector is a recessed socket sporting a center pin plus a pair of curved
blades (one locking); I've never had any luck matching that style of socket
connector so I guess that I'll need to replace it, unless someone has the
right plug, unused.

This unit appears to be a modestly newer than those documented in
1154B_BRPE_Parts_Catalog_Jul1960.pdf (which appears to only document up to
the BRPE11 punch and BRPEB8 base) although
215B_BRPE_Technical_Manual_May1971.pdf does seem to apply.

In 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 32 (Figure 1) the population
of the back-plate appears to correspond, so I think that PN #114466 may be
the matching power plug (however that PN is subsequently described as
"Connector, Receptacle (2 Pt)" rather than as the plug).  Note also in the
figure the four rubber grommets (PN #154697) affixed to both sides of the
base fore(ish) and aft.  What purpose are these intended to serve?

Also in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 33 (Figure 2) note the
two-part metal tape reel (PN #146689 "Disk, W/Hub" & #146690 "Disk,
W/Flange") that is used to dispense tape.  I seek one of these, or
guidance/experience in creating a substitute.

Also in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 35 (Figure 4) is
illustrated the "motor cover" that I'm missing (PN #143092 or perhaps
#142991).  Just askin' .

Finally in 1154B_BRPE_Parts_Catalog_Jun1966.pdf, page 44 (Figure 7) I'm
missing the chad box (PN #142933; appears to be a simple metal bin but the
HappyComputerGuy video on YouTube shows one in transparent plastic, which
makes a bit more sense) and then on page 45 (Figure 8) the "Guide, Tape" PN
#142983 has somehow been broken in half (looks like a lot of metal fatigue;
strange).  At least these are parts that I can manufacture for myself .
although an original chad box would be a lot nicer than anything that I'll
be able to produce.

Aside from the "parts call", above, my initial questions:

1.	295B-6504.pdf states that the LMU6 series (governed) motor is AC/DC.
I infer that if I simply supply 120VAC 60Hz the governing
components/circuitry will have no adverse effect, but that's not made clear
anywhere.  The curved-blade power socket seems to suggest that this
installation was intended for DC operation, so I'm reticent to simply supply
AC "and see what happens".  (Shaft turns freely and depressing the four
spring-ball oiling ports appears to indicate the presence of sufficient
light-weight oil, so other than modest cleaning the motor assembly appears
to be ready-to-go.)  Figure 5 (page 16) in 295B-6504.pdf is the applicable
schematic; there's no evidence of power supply polarization.  Is this
correct for DC operation (either orientation is fine)?  Can I simply use AC
without any changes?

2.	215B_BRPE_Technical_Manual_May1971.pdf has very little to say
regarding how the BRPE was driven ("deserialization" / "receiver set").
Sections 3.05 through 4.02 (page 21 of the PDF) provide a very generic
description of signaling, and then Figure 3 (page 22) documents a conceptual
diagram including a "SIGNAL REGISTER" with input "SYNCHRONIZING PULSE SENT
TO SIGNAL REGISTER" and output "FEED AND CODE PULSES SENT TO MAGNETS".  I've
not found any schematics for the BRPE base, however as it houses 9x diodes
and power resisters I'm guessing that the code pulses are "typical"
100Vdc'ish signals.  Is that correct?  Note that the
https://www.youtube.com/watch?v=-aZl8rMT8Aw video shows a 28Vdc power supply
present for some purpose; as it peaks at ~530 mA during operation I presume
that it's the magnet supply.  https://github.com/emooreatx/Teletype-BRPE/
certainly draws that relationship.

Timing of the code vs. feed pulses isn't stated anywhere, nor their
durations.  Figure 2 (Page 20) is rather stylized and implies that the feed
pulse is concurrent with the code pulses, which I guess based on initial
study of the mechanics could very well be true. Based on the time-line
across the top of Figure 3 it appears as if both code & feed pulses start
with the synchronizing pulse at 90 degrees before TDC and end ~80 degrees
after TDC, so a nominal duration of somewhat under a half-cycle.  It looks
like the mechanism deals with offsetting the actual punch and advance
actions.  (Yes the Arduino code in GitHub documents one timing approach; I'd
like to determine if it's the proper one .)

The synchronization pulse is just the raw magnetic pickup, so the
implementation of the "SIGNAL REGISTER" needs to both amplify/trigger and
then create the correctly timed (and gated in the case of the code) pulses.
It would be quite helpful to see the schematic & technical description of
the Teletype equipment that implemented this function!

As my primary use-case is based on a TTL source it looks like I'll need to
not only handle the triggering and timing but also opto-isolation of 10x 100
Vdc signals for the various relays (or maybe that's "only" 28Vdc).  Has
anyone here been down this road, even part way, before me?

3.	There really isn't any documentation that I can find that addresses
punch disassembly, cleaning, and reassembly . although proper lubrication is
addressed.  I'm not enthusiastic about tackling the breakdown necessary to
properly service the punch block/pins lacking documentation.  I'm hoping
that I can extract a subassembly that I can simply immerse in solvent or
otherwise apply solvent to selected points while working individual pins to
get them moving freely, and then relubricate.  Unfortunately I don't see any
way to accomplish this without a pretty complete disassembly :-<.
Suggestions?  I am assuming that a lightweight "sewing machine" oil will be
satisfactory when relubricating.  Is that correct?

I do spy https://www.navy-radio.com/tty/brpe.htm so maybe Nick has answers
(and more!) to all of my initial questions.

Thoughts, observations, experience, etc. that have a bearing on my BRPE will
be much appreciated.  And .

An early Happy New Year!  One hopes that 2024 will be less "interesting
times" than 2023.  But hope is not a method .

paul

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