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WE 7C Dial Assembly and dial speed adjustment for various dials

Started by TelePlay, May 07, 2020, 12:43:09 PM

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The ITT Kellogg TIMM from 1964 contains the following:


Trouble Shooting
1 Dial Troubles

     a: Dial pulse contacts             Adjust contacts or
         wrongly functioning.           replace dial.

     b:  Incorrect dial speed           Adjust dial speed or
          (For most conditions,         replace dial.
          dial speed must be
          considerably in error
          to cause trouble.)

[from page M1C-TRB Issue 1 8-64. This is page 14 of 136 in the TCI library file.]

  These adjustments could be made either in the field or in the repair shop, according to the manual. The #19 dial is equivalent to the WE 7-type. The general description of the #19 dial is on page M2A-DLS/19 which is page 26 of 136 in the TCI file.

"C'est pas une restauration, c'est une rénovation."--François Martin.


That would be great. I'm really interested in reading that guidance to see how it differs from how I've been adjusting dial speed on #6 and #7 dials.

Also, the #5 BSP disclosed that field techs could dial into the CO to get the speed of the dial being serviced. That would have allowed for field dial speed adjustment, back in the day.


Dial speed adjustment is covered in paragraph 5.5 of M2A-DLS/GEN (page 24/136 of TCI file).
"C'est pas une restauration, c'est une rénovation."--François Martin.


please get and review BSP 501-162-100 Page 18.  the adjustment I referred to was the "Gear Mesh" adjustment...


Quote from: Babybearjs on March 27, 2021, 08:55:20 PM
I have one on a yellow 564 and looked up the adjustment BSP. the governor wasn't braking and I wanted to adjust it. after reading and tinkering with the dial I discvovered to leave it alone as it took care of itself.  the phone works fine now.

Well, we were talking apples and oranges here. Your post said "the governor wasn't braking and I wanted to adjust it" which to me seemed to say the dial speed was not right because the coil spring based governor brakes were not working correctly.

When in fact, what you were trying to do was adjust the gear mesh between the main spring gear and the governor/pulse gear train cage. This was fully addressed in steps 9 and 17 of this topics assembly instructions in posts and in the images duplicated below.

Yes, the gear train can be jammed up against the main spring gear so tightly that the dial will not turn in either direction or it can be so far away from the main spring gear that the gears do not mesh and the the finger wheel will return without pulsing or partial pulsing and a not very good sound of something like gears stripping.

The attached BSP document number you sent me to is a great use for anyone working with WE dials but after explaining how to adjust the speed of a #2, #4, or #5 dial, it states on page 12:  "3.16 The speed of 6-, 7-, and 8-type dials is not adjustable and the dial should be replaced when speed requirements are not met" and that that verifies what I have been saying, there is no BSP for WE type dials.

However, thanks to poplar1, the ITT-Kellogg Telephone Instrument Maintenance Manual - circa 1964-65 in the TCI library (also attached here as a pdf), does tell how one can adjust the speed on a dial that uses a coiled spring to adjust the brakes, increase or decrease dial speed, on a WE #6, #7 or any other WE dial that uses a center coiled spring in the governor. This is the exact way I have been adjusting out of spec center coil spring governor successfully for years. This is from page 24 of the ITT manual:

"5.5 DIAL SPEED:  Check the speed of the dial on a reliable pulse speed tester. If the speed falls outside the range given under the TEST heading in the individual descriptive sub-section, readjust it to be within the range given under the heading of READJUST. The speed is controlled by the end-to-end tension of the governor spring; reducing the inward tension of the spring causes the speed to be reduced and increasing the inward tension causes the speed to be increased.  Adjust the spring tension by curving or flattening the spring at the center of the loop, using a pair of tweezers with flat jaws. Be sure that the loop of the spring is kept approximately parallel with the governor housing and has a clearance of about 1/64" from all other parts of the governor mechanism, except for the tips of the spring connecting to the weights."

One must have a way to measure the dial pulse speed before adjusting the governor of any dial. And, bending a coiled spring is not easy in that the amount of bend put into the spring will only be a small percentage of the physical bend of the spring. I've found that working with the 90° bend where the arm meets the coils is easier than messing with the coil itself. And, a very small change in the spring makes a significant change to the dial speed, either way. It's a multi step process. Determine the dial speed, remove the spring, bend the spring, put the spring back on the brakes, determine the new dial speed and if not in spec, remove the spring and bend it again, and again and again until the dial pulses within spec.

On page 11 of the attached BSP states how a field tech could check the dial speed of a phone saying:

"Dial Speed Test

3.13:  In central offices equipped with automatic dial test equipment, test dial speed in the following manner:

(1) Obtain dial tone.
(2) Dial code number for dial speed test.
(3) After dial tone is heard again, dial one of the following digits:
     • Digit number 2 (test for 8 to 11 pulses per second)
     • Digit number 3 (readjust, test for 9.5 to 10.5 pulses per second).
(4) Listen for dial tone again, dial digit 0.

One of the following audible signals will indicate how the dial meets the requirements of the test:
     a) Ringing induction-dial speed satisfactory
     b) Rapidly interrupted dial tone-dial speed fast
     c) Slowly interrupted dial tone-dial speed"

I doubt that is available today so one needs an analyzer, audacity or any other way of measuring dial speed before beginning to adjust the governor of any dial.

As paragraph 5.5 states, making the spring smaller in diameter thereby putting more tension on the brakes, pulling the brakes inward, will require more centrifugal force for the brake to make contact with the governor race so the dial will speed up. Making the spring larger in diameter will require less centrifugal force for the brake to make contact with the governor race so the dial will slow down. It's all about how much tension the coiled governor brake spring is applied to the brakes. Easier for the brakes to expand, more contact, more braking and decreased dial speed. Harder for the brakes to expand, less contact, less braking and increased dial speed.

While it's too bad the original reply had nothing to do with the governor itself, this did lead to a lot of valuable information anyone interested in adjusting the speed of a dial can use.

And, the same can be done with AE type governors that have two spring wings that control the amount of braking done within the AE type governor race as stated in the TCI library document 502-gsp-473-822-700-i2-dial-speed-adjustment also attached below. And this applies to very old none WE dials such as the turn of the century Mercedes dials

and other manufacturers dials that used the spring wing braking mechanism as shown in the above image.

So, that should cover governor adjustment except for the fully enclosed governors found on newer dials such as the #9C which can not be adjusted.

Gear mesh is important to proper dial operation but it has nothing to do with the adjustment of dial speed controlled by a governor.


Wow. This has been a great thread, thanks to everyone for their input here.
A collector of  'Monochrome Phones with Sepia Tones'   ...and a Duck!
Vintage Phones - 10% man made, 90% Tribble


Quote from: kleenax on March 28, 2021, 06:29:45 PM
I think that I have a copy of the BSP that shows how to adjust governor on #7 - #9 dials; I will look tomorrow.

BSP Attached
Ray Kotke
Recumbent Casting, LLC


Quote from: kleenax on April 13, 2021, 08:27:20 PM
BSP Attached

This BSP covers dial speed adjustment for the 5-type dials only.

The only adjustment for 6-, 7-, and 8-type dials is for the gear mesh, to prevent "excessive noise, binding, or lockup." (paragraph 3.29).

           3.16  The speed of 6-, 7-, and 8-type dials is not
                    adjustable and the dial should be replaced
           when speed requirements are not met.

The 9C dial has the same mechanism as the 8-type.
"C'est pas une restauration, c'est une rénovation."--François Martin.


well, thats the only information available on that subject.... I followed the information and was able to get my #7 dial to work OK...


Quote from: Babybearjs on April 14, 2021, 10:30:46 PM
well, thats the only information available on that subject.... I followed the information and was able to get my #7 dial to work OK...

Well, then, your initial reply, which was vague and unclear as to what you were doing, to this topic that was created to deal with the assembly of a 7C dial had nothing to do with this topic. Your issue should of been posted in a topic of its own listing the perceived problems or issues noticed in your dial which turned out to be, I think, the improper main spring gear meshing with the gear train. A topic, with images, discussing the irregularities during operation, the diagnosed cause and what was done to resolve the irregularities would have been a great addition to the knowledge content of this form, much better than what was first posted in a reply in which your said in a few, vague words saying the dial had a problem, you read some non-stated BSP, you futzed around with the dial for a bit, found that what you were doing was too complicated for you to understand, gave up working on the dial and poof, the dial was then working just fine.

While nothing new was learned from your tangential, off topic replies (proper gear meshing instructions were posted in the original topic instructions of dial assembly in steps 7 and 19), I'd like to thank all of those members who helped decipher your vaguely described problem and subsequent work as not being a dial speed adjustment and then took the personal time to look for, find and post the documents or links that addressed the adjustment of dial speed (governor adjustment on #2, 4, 5 and #6 to 9 dials if they use the center coil spring to control the governor brakes) so any member who now has a true dial speed problem, after properly cleaning and oiling the dial with the proper lubricants now knows how to increase or decrease the dial speed to get it back into spec, near 10 PPS.

End the end, not only is this is a good example of hijacking a topic but also how thanks to members other taking the time to clarify your raised issue got the thread back on topic and in that process significantly adding to the topic so that now anything any member would ever need to know about how to adjust a dial's speed can found in one place, in this topic.

While I realize few will ever attempt this level of dial restoration, it can be done, is not difficult and with the significant contributions to this topic by several members it now provides anyone wanting to correctly clean and adjust a dial with everything they need to do so.

Seems everyone learned a lot in this topic.


With this information, I may finally get up the courage to try rebuilding a dial.

However, Steve Hilsz has now done three dials for me, and his cost is very reasonable, his turnaround is quick and I have been very satisfied with his work. If you aren't sure about working on your dial, I wholeheartedly recommend Steve.