Author Topic: Advice to repair an AE/GTE rotary dial unit - 975C  (Read 708 times)

Offline hotrodjohn71

  • *
  • Posts: 16
  • Its off the hook!
Advice to repair an AE/GTE rotary dial unit - 975C
« on: May 06, 2017, 12:17:07 PM »
Please forgive and direct me if this posted in incorrect category.

I have a phoneco payphone setup that I mounted in an english phonebooth I built. I got a dialgozmo unit which works well on my att uverse system. The problem I have is the rotary dial unit on my phone skips sometimes and wont pulse the correct number of times for the given # dialed. its almost like a little clutch or something in the unit isnt 'catching' all the time.
Im pretty good at taking things apart and analyzing and fixing them unless parts are too far worn or gone. I have a clock oil pen, but I want to ask the experts first on here for any advice before I tear into it, or if its not worth trying at all.
I have no problem with grinding off pop rivets if necessary to get inside of a component if need be.
Thank you
« Last Edit: May 07, 2017, 03:48:27 PM by TelePlay »

Offline mentalstampede

  • no deposit, no return
  • *
  • Posts: 451
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #1 on: May 06, 2017, 01:49:55 PM »
Some pictures of your actual phone would be helpful; the phoneco products are a blend of original and reproduction parts from different manufacturers, so a photograph would be very helpful for us to see what you actually have.

Regardless, there should not be any need for grinding or drilling rivets. The upper housing should easily come off the phone by turning the key located in the center below the dial. You may or may not have a wiring harness to disconnect at this point depending on what you have. Once that is off, you should be able to remove a couple screws that hold the coin chute in place and get access to the dial mounting hardware. Once you get the dial off, it can be inspected and serviced.
My name is Kenn, and I like telephones.

“Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something.” --Robert Heinlein

Offline TelePlay

  • Global Moderator
  • *****
  • Posts: 7251
    • . . . times keep changin'
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #2 on: May 06, 2017, 01:55:26 PM »
Some pictures of your actual phone would be helpful; the phoneco products are a blend of original and reproduction parts from different manufacturers, so a photograph would be very helpful for us to see what you actually have.

I'm pretty sure what Kenn meant was to take one photo of the outside (full front) and then take pictures of the inside including the back of the dial, for sure, and any and all circuit boards or terminal boards and wiring within the phone.

Offline mentalstampede

  • no deposit, no return
  • *
  • Posts: 451
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #3 on: May 06, 2017, 01:56:28 PM »
I'm pretty sure what Kenn meant was to take one photo of the outside (full front) and then take pictures of the inside including the back of the dial, for sure, and any and all circuit boards or terminal boards and wiring within the phone.

Absolutely.
My name is Kenn, and I like telephones.

“Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something.” --Robert Heinlein

Offline hotrodjohn71

  • *
  • Posts: 16
  • Its off the hook!
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #4 on: May 06, 2017, 03:59:58 PM »
Hi guys, thanks for your replies. Metalstampede, I like your slogan at the bottom of your comments. I too have always liked telephones. I go right to them whenever im at an antique store.
But anyways, here are a couple images of my unit. it looks very dry, no lubrication anywhere I can see.
I havent gone anydeeper in disassembly than these images.

Offline mentalstampede

  • no deposit, no return
  • *
  • Posts: 451
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #5 on: May 06, 2017, 05:02:20 PM »
Most everything you need to service is accessible without further disassembly. All of the contacts and the mechanisms that activate them are right there on the back of the dial. The oblong white plastic piece at the bottom is the cam that opens the pulsing contacts. For each number dialed, you should verify that the cam opens the contacts, e.g. for a 5 the contacts should open 5 times, for a 6 six times, etc. The contacts to the right as you're looking at the back of the dial are open when the dial is at rest, and they should close whenever the dial is moved from the stop. These are the contacts that mute the receiver when dialing to prevent the pulses from being heard.

If you have a pin oiler, lightly lubricate the areas where necessary, but make absolutely sure you do not get any oil in the regulator assembly (the round plastic housing to the op-left end of the diagonal shaft.
My name is Kenn, and I like telephones.

“Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something.” --Robert Heinlein

Offline hotrodjohn71

  • *
  • Posts: 16
  • Its off the hook!
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #6 on: May 06, 2017, 05:13:56 PM »
Hi mentalstampede, Ive been studying this unit about an hour. as far as the contacts and the cam that opens them, it all looks good. the problem is the clutch mechanism (?) which should innitiate the process when the dial is let go on any given # sometimes doesnt 'bite' right away. so sometimes when dialing a 4, only 2 pulses will be innitiated because the clutch slipped, or when dialing an 8, it might only dial a 5,6, or 7 because the clutch slipps and the dial retracts a little before it begins the process.
I appologize if my terminology is rudementary. The clutch as it were seems to be undearneath the pot metal housing. The plastic gears seem to be in great shape.
John

Offline TelePlay

  • Global Moderator
  • *****
  • Posts: 7251
    • . . . times keep changin'
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #7 on: May 06, 2017, 08:28:04 PM »
You may need to remove the finger wheel, starting with the number card.

This topic

     http://www.classicrotaryphones.com/forum/index.php?topic=5833.msg70508#msg70508

has good pictures showing what's under the paper card (you can see how the locking mechanism works) and this link

     http://www.telephonecollectors.info/index.php?option=com_docman&task=doc_details&Itemid=2&gid=1921

shows a dial bezel similar to yours, same works under the paper card.

The gold tab (which you can not see under the paper number card) is moved counter clockwise about 1/4 to 3/8 inch



and once released, the metal ring lifts off by lifting at the 10 o'clock position (a tab holds the ring in place near the tip of the finger stop - 5 o'clock position).



That should do it (seems like a standard AE/GTE dial). The unscrew the large center retaining screw to get the finger wheel of to see what's going on underneath.

Offline dsk

  • **
  • Posts: 3772
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #8 on: May 07, 2017, 04:29:26 AM »
I would try the most simple adjustments first.
The plastic screw marked on the picture is pretty easy to tighten to much, try to loosen it a bit, 90-180 deg (counterclockwise) will not harm, and it is easy to turn it back if its not getting better.

dsk
 
« Last Edit: May 07, 2017, 06:06:39 AM by dsk »

Online Ktownphoneco

  • **
  • Posts: 990
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #9 on: May 07, 2017, 09:01:35 AM »
HRJ ....  I would follow Teleplay's directions on removing the finger wheel, and have a look at the ratchet pawl that pulls the ratchet / main gear counter clockwise when you release the finger wheel after dialing a digit.    If I understand your description of the problem correctly, it sounds as though the ratchet pawl is skipping over a tooth or two on the ratchet / main gear.       The only way to inspect those particular parts is to remove the finger wheel.   
I've attached a picture so you have an idea what I'm referring to.     Check the ratchet / main gear teeth, both the upper gear teeth which the ratchet pawl pulls on as it spins the dial back to the rest position, and the lower teeth that drive the worm wheel shaft.     Also check the ratchet pawl spring, and make sure it's pulling or holding the ratchet pawl against the ratchet gear teeth.  If there are any missing or worn teeth, or the spring isn't applying enough tension to the ratchet pawl, the dial will exhibit the symptoms I think your describing.    Click the picture for an enlarged view.
I've also included drawings of a typical A.E. dial showing the proper names for the various parts.


Jeff Lamb

 
« Last Edit: May 07, 2017, 09:46:14 AM by Ktownphoneco »

Offline hotrodjohn71

  • *
  • Posts: 16
  • Its off the hook!
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #10 on: May 07, 2017, 10:44:15 AM »
OK, thank you guys so much. This is great information.
One question. Do you remove the number card before removing the escutchion ring? And if so, how without damaging it.
 I have a number card with a clear plastic lense over it.

Online Ktownphoneco

  • **
  • Posts: 990
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #11 on: May 07, 2017, 11:10:30 AM »
No.    Insert the tip of the small screw driver in the spot Teleplay has indicated, and between the acetate window and the black retainer ring.   When the tip stops, feel for the brass tab (not visible in Teleplay's picture, as it's hidden by the retainer ring), and once you feel it with the tip of the screw driver, push the tab counter clockwise until you feel it come up against something and stop.   It doesn't move very far, maybe 1/4 to 3/8's of an inch.
Gently lift up on the tip of the screw driver, and the entire retainer ring, acetate window and dial number card should lift up and out of the recess in the finger wheel, exposing the disk and / or machine screw holding the finger wheel on the dial.    Unscrew that machine screw and remove the finger wheel.

Jeff

Offline TelePlay

  • Global Moderator
  • *****
  • Posts: 7251
    • . . . times keep changin'
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #12 on: May 07, 2017, 03:53:44 PM »
OK, thank you guys so much. This is great information.
One question. Do you remove the number card before removing the escutchion ring? And if so, how without damaging it.
 I have a number card with a clear plastic lense over it.

Yes, sorry. What Jeff said in the post right above this.

I forgot to mention (it's posted in the topic link I provided) that the member submitting the photos took them without the number card in place to show what is happening once the small flat device is stuck in between the number card ring and the number card/acetate window.

On your dial, you will be doing what's seen in those pictures without the number card but you won't be able to see what you are doing because your number card will be hiding what's below it.

Once you get it apart, you can practice installing and removing just the ring (without the number card) to "get the feel" of how to do it in the future.

Offline hotrodjohn71

  • *
  • Posts: 16
  • Its off the hook!
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #13 on: May 09, 2017, 12:26:29 PM »
Its fixed! Thank you guys so much for consideration of my question and taking the time to share advice.

I was able to get the number card ring off without any damage to the number card and got the finger dial off and examined everything closely.
It appeared the ratchet pawl was only intermittently functioning correctly but the ratchet gear and other gears looked good. Never having worked on one of these before, I cannot say with certainty but it appeared the ratchet pawl spring (which is plastic and one piece with the ratchet pawl) seemed like it ought to have a bit more spring tension, but nevertheless. So I carefully oiled the moving parts including the little shaft the ratchet pawl pivoted on (except the governor) and put it back together and it works great every time. All of the works were quite dry whithou any lube I could see.
Thank you :)
« Last Edit: May 09, 2017, 12:43:19 PM by hotrodjohn71 »

Offline TelePlay

  • Global Moderator
  • *****
  • Posts: 7251
    • . . . times keep changin'
Re: Advice to repair an AE/GTE rotary dial unit - 975C
« Reply #14 on: May 09, 2017, 01:22:58 PM »
It appeared the ratchet pawl was only intermittently functioning correctly but the ratchet gear and other gears looked good. Never having worked on one of these before, I cannot say with certainty but it appeared the ratchet pawl spring (which is plastic and one piece with the ratchet pawl) seemed like it ought to have a bit more spring tension, but nevertheless. So I carefully oiled the moving parts including the little shaft the ratchet pawl pivoted on (except the governor) and put it back together and it works great every time.

Thanks for letting us know and glad you got it to work. That makes sense in that the lack of oil was keeping the part from quickly (about 0.1 seconds) to catch or pulse the next digit dialed.

At least two things can happen related to oil: Oil can collect dirt and dust and gum up parts over time and lack of oil allow friction to keep parts from moving (always best to remove excess oil) and using the right kind of oil is also important.

There is a topic on dial oils on the forum which may be of interest to you. The list of oils mentioned in the topic is at this reply.

     http://www.classicrotaryphones.com/forum/index.php?topic=7899.msg124966#msg124966

Glad to know it works and the fix was easy, and you learned how to take the front of an AE dial apart on top of it all.