Hi all. I am actually making some good progress on this LPR! The motor does not run when this new LPR is connected to the 36 pin connector, but I am able to get the motor running if I plug in the old LPR electrically, but the new LPR is
installed mechanically. Doing this, I was able to get it to run open, run closed and while running closed, I was able to get the remote tape feed out function to work! Took a lot of adjusting and oiling. It isn’t 100% repeatable but I think with some more
time and letting the oil penetrate various areas I think it will start behaving repeatably. Since the little blade broke off, I suspect I am wont getting the LTRS that this blade provides, but that isn’t a big deal right now.
Now I want to put it on a loop and see if the selector/bars thingies are working or not. To do this, the easiest way is to try to figure out why the motor doesn’t run when I have this new unit plugged in. This will kill two birds with one
solution. First bird is getting the motor running with this LPR and second bird is getting the selector magnets connected up to my long cable and ¼” plug to make it easier to plug into the loop jacks.
Regarding the motor not running with this LPR, I did find the reason. My old unit has pins 35 and 36 shorted. The new unit uses shielded cables, and the shield is used on pin 35. I’ve looked through a lot of manuals and I found this detail.
See below the short between C-35 and C-36. This jumper is located underneath the 36 pin connector mounted on the rear of the LPR. Not easy to get to.
See the call out for C-35 of note 10 and 14 which says…
10 – WIRED FOR 20 OR 30 MIL OPERATION. UNITS USING 173850 SHIELDED CABLE ON THE
“G” CONNECTOR, OMIT STRAP BETWEEN TERMINALS 35 AND 36 CONNECT “G” WIRE
TO TERMINAL 35
14 – THIS CONNECTION IS APPLICABLE ONLY ON COMPATIBLE UNITS CONTAINING
R.F. SUPPRESION WIRING ON MATING CONNECTOR.
ON OTHER NON-COMPATIBLE (INCLUDING BELL SYSTEM) UNITS IF EQUIPPED
WITH A SHIELDED CABLE, THE SHIELD “G” WIRE IS TO BE DISABLED.
So it seems I am in the situation where I have a shielded LPR but base expecting non-shielded connections. I think that puts me in the “non-compatible” camp and therefore I believe I should cut this G wire and jumper 35 and 36 together.
I tested this theory and using a jumper them, and the motor did indeed run perfectly. So now I know what I need to do. The question is what is the best way to do it.
I could try to solder these very tiny contacts underneath (hard to reach), try to clean the oil away to make a good solder joint. But this is going to be tough for sure. I decided to look if I could instead, make the jumper on the terminal
strips on the base.
I figured if the lack of this jumper is preventing the motor from running, these signals must be going back to the motor ultimately.
I looked through a TON of documentation but the only diagram I could find is for the bases that are designed to work with the shielded cables (military ROTR units) and therefore receptacle (base-side) shows this:
This does not show where 35 and 36 terminate on the terminal strip in the photo above. I have tried to ohm it out but this is an area I don’t want to make a mistake. I’d be happier if I could find documentation evidence for the way my
base is wired.
So I’m reaching out to the good folks here on the list if someone can help point me to the right document that reflects the base, and therefore the wiring, that I have.
Here is the list of documents I’ve been working with, plus several physical manuals I have at the home QTH
THANKS everyone!
From: [email protected] <[email protected]>
On Behalf Of W2HX
Sent: Wednesday, January 25, 2023 10:00 PM
To: Nick England <[email protected]>
Cc: Greenkeys <[email protected]>
Subject: Re: [GreenKeys] LPR35 BRP
Thanks everyone for lots of good clues. I am not reading through this manual “reperf-94456-6302.pdf” from Nick’s site and it has lots of pertinent information.
73 Eugene W2HX
Subscribe to my Youtube Channel: https://www.youtube.com/@w2hx/videos
From: Nick England <[email protected]>
Sent: Wednesday, January 25, 2023 9:07 PM
To: W2HX <[email protected]>
Cc: Greenkeys <[email protected]>
Subject: Re: [GreenKeys] LPR35 BRP
A handy place to look is
This shows the LPR35 used in TT-274 ROTR
which says "manual tape backspace and remote control non-interfering LETTERS tape feed out."
Nick England K4NYW
www.navy-radio.com
On Wed, Jan 25, 2023 at 5:57 PM W2HX <[email protected]> wrote:
Hi all,
In my question to produce fully punched tape, I acquired this LPR35 BRP unit. I hope to replace the hanging chad unit in my ROTR. I have NOT yet installed this on the ROTR base, I’m just getting familiar with it first.
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230125_163630.jpg
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230111_175044.jpg
It appears to have some modifications for tape feed out. Perhaps some automatic tape feed out control as might be evidenced by this solenoid. Remote? Interfering? Non-interfering? Blank tape feed out?
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230125_163635.jpg
However, manually actuating the solenoid does pitifully little, I can’t imagine how this could do anything. Maybe once things get in motion through the motor, this will do more?
My current ROTR’s LPR has a lever which I believe is manual LTRS feed out function.
There is this hexagonal attachment on this shaft which seems to be possibly related
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230125_163641.jpg
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230122_192307.jpg
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230122_191140.jpg
Now for the problem. As I picked up this unit with almost no force on it, this piece broke off.
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230125_163652.jpg
There were two screws that attached it to the hexagonal shaft.
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230122_191148.jpg
these two screws look like they sheared off, but I suspect they were previously broken and just sitting in the holes with some grease. I can’t see how what I did could shear two screws, but alas, here we are.
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230122_191218.jpg
here is the rear of the shaft.
https://w2hx.com/x/TTY/28-ROTR/LPR%2035%20BRP%20Full%20Chad%20Reperf/20230122_192249.jpg
I plan to order replacement parts from Mr. RTTY but I wanted to understand what I’ve lost and what I’ll gain from replacement parts.
Anyone familiar with this set up on the LPR35? What do I have? Once I replace the shaft, how do I actuate that solenoid? AC line voltage? Dc voltage?
Any pointers greatly appreciated.
73 Eugene W2HX
Subscribe to my Youtube Channel: https://www.youtube.com/@w2hx/videos
______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch
>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]