[GreenKeys] BRPE11

Fri Jan 19 06:46:40 EST 2024

I removed my punch block this morning and verified that it isn't a contributing cause to my problem with stuck linkages.  It looks fine to me, and now that I can get a closer look I can see that what I thought to be a "wire" is actually a thin blade seen exactly end-on!  Wiser am I now as to how my tape guide mechanism is constructed, and operates :->.  I agree with the Teletype engineers that feeding 7/8” tape is not supported by the BRPE21.

I think that one could create a small edge-guide that could be attached on a temporary basis to the front of the Tape Guide Bracket (PN# 142942) to ensure that 7/8” tape is fed correctly as a narrower alternative to 1” tape in order to correctly support 6- and 7-level tape.

From: pbirkel at gmail.com 
Sent: Thursday, January 18, 2024 6:28 AM
To: Nick England <navy.radio at gmail.com>
Cc: greenkeys at mailman.qth.net
Subject: RE: [GreenKeys] BRPE11

I’ve been guessing about the BRPEB6 based on the photo and ancillary sources.  It’s nice to see official confirmation on that point, and the 6 or 7-level capability.  Thank you for pointing that out :->.  The seller saw only 4 magnets on the right, so is it the case that the price list is for a “generic” assembly and there are further variations (perhaps using the 143056 block but with or without the 9th magnet)?  I’ve asked the seller to take off the punch cover and post photos of the mechanism.

Based on my BRPE21, an 8-level (inline) punch block can indeed do-it-all.  The variations are handled by switching off selected magnets and/or reconfiguring the tape feed/positioning mechanism (the feed-pan snaps into two positions to align the guiding edge of the tape; see Figure 3 in 1154B_BRPE_Parts_Catalog_Dec1970.pdf).  Looking at Figure 4 the operation/use of the “adjustable” mechanism is unclear.  My BRPE21, presumably with the 146261 block, has this mechanism.  My interpretation of the table is that it affects the positioning of the “biasing spring” in order to handle the narrow 5-level 11/16” tape.  However PN 142897 and 146262 look like “plates” to me, not even leaf springs. 1154B_BRPE_Parts_Catalog_Jul1960.pdf, Figure 1-6, is a bit clearer that 142897 is creating a tape contra-edge guide that is located just prior to the tape reaching the punch pins.  As 142897 is slotted, presumably it’s factory-set for 7/8” tape in the BRPE11.

The Figure 4 diagram of the ADJUSTABLE block appears to be incomplete as 146262 never enters the tape path, and it’s shaped differently in my BRPE21 there is instead a very small wire affixed to the back-side of that part that drops into the tape path, or not, depending on position.  There is also a movable shoe over the tape that is not diagrammed; presumably it was a later innovation.  I don’t think that a wire rubbing along the tape contra-edge would be a good idea, so I need to examine this part of the mechanism more carefully, but at least I now have some insights into the purpose of the lever that actuates this part of the mechanism.

WRT driver electronics, I’m working on that starting from Eric Moore / Guy Fedorkow design.  My objectives are 5- thru 8-level support for USB serial, RS-232 serial, and parallel interfaces, plus local self-test/alignment patterns.  I’m using a Mean Well LRS-350-24 SMPS which is adjustable up to 28.8 Vdc augmented by a TVS across the output to make up for any deficiencies in SMPS back-EMF transient protection.  The P6KE33CA looks to me like a good TVS choice:

Polarity:                        Bidirectional                  

Working Voltage:           28.20V              

Breakdown Voltage:      31.40~34.70V

Clamping Voltage:         45.7V 

Peak Pulse Current:       13.3A

From: https://www.mouser.com/datasheet/2/240/media-3320979.pdf 

The LRS-350-24 spec claims Overvoltage Protection in the range 28.8 - 33.6V (28.8V is the max. adjustable operating voltage) so presumably transients up to at least 33.6V are OK, and the various components are likely rated (significantly?) higher than that.  The TVS should enter conduction at 31.4V, well before 33.6V, and the final clamping voltage of 45.7V isn't unreasonably high.  The LRS-350-48 in that SMPS series, where I'd expect a lot of component commonality, has a max. adjusted voltage of 52.8V so I'm guessing that the series has the ability to handle at least that much back-voltage.  I've never worked with a TVS (or a SMPS with external output transient protection) before so I'm just going by "book learning" on this one.

WRT back-EMF, the BRPE base includes a top-hat "freewheeling" diode for that purpose wired in parallel with the magnet-resistor (25 ohm, 2W?) serial combination for each magnet; a standard circuit design.  Which is a start but I doubt that those diodes are exactly "fast-acting/recovery"; they're unmarked but probably from the (maybe mid) 70's.  While it's possible that a SMPS was in use in that era it's also possible otherwise.  That said, Eric Moore doesn’t seem to have encountered any problems with his use of a SMPS.

Working on the belt-and-suspenders philosophy augmented by “measure twice, cut once” engineering :->.  Slow-n-steady wins the race!

From: Nick England <navy.radio at gmail.com <mailto:navy.radio at gmail.com> > 
Sent: Wednesday, January 17, 2024 1:17 PM
To: pbirkel at gmail.com <mailto:pbirkel at gmail.com> 
Cc: greenkeys at mailman.qth.net <mailto:greenkeys at mailman.qth.net> 
Subject: Re: [GreenKeys] BRPE11

Correction - 

I said " I thought that the parts book showed that the adjustable punch block would handle 5-8 level?"

That is the 146261 punch block, but I missed 143056 which is 6-8 level, 7/8" or 1" tape - I suspect that's what the BRPE11 has.

Nick England K4NYW
www.navy-radio.com <http://www.navy-radio.com> 

On Wed, Jan 17, 2024 at 1:00 PM Nick England <navy.radio at gmail.com <mailto:navy.radio at gmail.com> > wrote:

According to the 1969 catalog, BRPE11 + BRPEB6 is 

6 , 7 , or 8-level, 7/8" or 1" width, In-line feed hole

633 wpm

28VDC 1 ampere signal and tape feed out magnets 

See pdf page 10 

https://www.navy-radio.com/manuals/tty/tty-equip-price-1969-01.pdf

I thought that the parts book showed that the adjustable punch block would handle 5-8 level?

I really need to get back to my BRPE project - I got a couple of the typesetter 6-level units (with leading feed hole) and convinced some machinist buddies that making a new 5-level in-line punch block would be a "challenge". Now I need to build some driver electronics and figure out how to feed it a character stream.

https://www.navy-radio.com/tty/brpe.htm

Nick England K4NYW
www.navy-radio.com <http://www.navy-radio.com> 

On Wed, Jan 17, 2024 at 11:25 AM <pbirkel at gmail.com <mailto:pbirkel at gmail.com> > wrote:

Of possible interest is a poorly identified (and a bit rough) BRPE11 on eBay: https://www.ebay.com/itm/296166916217

I suspect from other sources (https://museum.wales/collections/online/object/a7dea37f-0f0a-3cfc-833e-f22b59972974/Paper-tape-puncher/) that’s a BRPE6 base -- hence the electrical support for an 8-level punch.  However the CDC 160 used the BRPE11 and that was a 7-level paper I/O system.  So apparently this may be a 7-level unit.  The vendor confirmed that there are only 4 relays/solenoids on the right.  I think that the mechanics and tape feed ought to work fine as a 6-level unit given the design of my BRPE21 tape feed mechanism.

I’ve suggested that the seller remove the punch cover and post suitable pictures.  And relabel the listing appropriately!

Unfortunately this unit falls in the valley between supporting the much more common 5-level and 8-level tapes.

Interestingly https://collection.sciencemuseumgroup.org.uk/objects/co62588/westrex-8-hole-paper-tape-punch-punch claims that a “Westrex” unit used a BRPE11, yet was “8 hole”.  I suspect that they included the feed hole in the count.

The "laid back" reel support is interesting (ignoring the fact that the reel isn't properly engaged in the photo).  That design is confirmed by:  https://www.computerhistory.org/collections/catalog/102696402 

paul

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