Western Electric dials from #6 through #10!

[zuperdee]

As I updated my 500 history recently, I started examining the differences between the #7, #8, and #9 dials, and I slowly began to realize something: There seems to be a great deal of misunderstanding out there about these dials! For some reason, many purists seem to think the #9 dials are inferior, for reasons I simply do not understand.

As I have examined Western Electric dials lately, I have come to realize: From the #6 dial on, the mechanisms on all of these dials are virtually 100% identical, and the differences lie mainly in the way they are assembled and framed! The mechanism used in the #6, #7, #8, and #9 dials seem to represent the pinnacle of W.E. rotary dial technology, and from #6 on, the changes consisted mainly of minor tweaks to the dials' manufacturing and framing.

I need more data, but so far, this is what I've been able to gather:

The #6 dial was developed to replace the #5 dial used in the Western Electric 302, and it may well have been developed in parallel with the #7 dial, for all I know. The biggest change made in the mechanism was to have the pulsing contacts be actuated by a single nylon cam lobe driven directly by the gear train, which was intended to increase the uniformity and accuracy of the pulses.

The #7 dial is mechanically just like the #6 dial, but with a larger die-cast aluminum frame designed for the model 500 set.

The #8 dial is mechanically just like the #7 dial, but tweaked slightly for manufacturing efficiency--for example: the frame for the main mechanism is now made entirely of stamped steel instead of die-cast aluminum as the #6 and #7 dials were, and the frame is riveted together. In later years, they would switch from rivets to die-stamping. The #8 dial also places an emphasis on making the mechanism as compact as possible for use in the Princess phone. :-) The mechanism frame is then riveted to a front piece for the faceplate.

The #9 dial, though first introduced in the 500 set in 1965, is actually a very simple evolution of the #8 dial introduced in the Princess phone in 1959! Look at the mechanism, folks--it is EXACTLY the same as the #8 dial, and the mechanism frame is exactly the same, too. The only difference is that the mechanism is riveted to a slightly larger front piece that is designed to accommodate the larger faceplate of the model 500 set.

The #10 dial is mechanically similar to the #9 dial, but miniaturized and given a moving finger stop. The #10 dial also has JUST pulsing contacts, and lacks the traditional shunting contacts for the receiver. My guess is that W.E. felt there was no need to go to all the expense of providing another set of contacts to mute the receiver while dialing on this one, since the user would not be likely to hold a Trimline phone up to his ear while dialing.

I am planning ultimately to compile a history of rotary dials in addition to my 500/1500/2500 history. Any thoughts or suggestions so far?

[Phonesrfun]

For starters, I am wondering when they came out with the #6 dial.  The reason I ask this is that when reading the 1949 Bell Labs article on the "soon-to-be-released" 500 set, they talk a lot about the new dial.  Amongst other things was the new nylon lobe for creating the pulses as opposed to the older way of having a ratchet and pawl on the older dials.  Older dials probably meant #5 and earlier.

So, I am wondering if the #7 dial for the new 500 and the #6 dial were being worked on concurrently.

One other thing is the dial on Dan/Panther's trial set.  If you go back and look at the thread, you will see some detailed pictures of that dial's mechanism and construction.  A couple of interesting points about that dial.

• It has a gear train unlike any other WE dial
• It has a nylon gear
• According to Dan, it has a quieter sound than other WE dials (probably due to the  nylon gear)

In that thread, we have wondered why this gear train that seems to be quieter did not make it to production.  Probably a matter of cost, or perhaps something about the gear train lay-out was inherently problematic.

Anyway, some things to chew on.

[Dennis Markham]

My non-scientific study of the #6 dial indicates to me that it it is numerically correct in that it is the bridge between the earlier dials (#2, #4, #5) and the later #7 dial.  In addition to it being a 3 inch dial to fit in the earlier sets, it also has the terminal screws as did the earlier dials.  However the removable contacts resemble the later #7 dial.  Also the main gear is similar if not exactly like the #7 dial.  Also a dust cover appears on the #6.  Perhaps (just guessing) the #7 may have been on the scene prior to the #6 but the #6 was designed as a replacement for sets still requiring a 3 inch dial...like the 300 series...since the 354 was a later production wall phone.  Wasn't the 354 even still being released after the 554?  Perhaps I have that time-table wrong.

I think that the later dials, #8/#9 may have had similar characteristics to the #7 as far as function, but the construction and use of plastic over steel/brass (gears) was another change that cheapened the durability of the dial.  Maybe this was the early edge of the "throw-away" world in which we live now.  Where it became cheaper to throw away a dial that was problematic rather than service it.  Maybe it didn't cheapen it at all and they are as equally durable as so many exist today and continue to function.  In reality the plastic may be less prone to corrosion and/or the accumulation of dust/moisture which caused problems in the earlier dials.  

I still like the older ones better, not only for the way they "sound" but they're easier to service.  But perhaps the later dials need less servicing.

[Dan/Panther]

Zuperdee;
Sometimes gear layout, meaning the way gears mesh, even though they accomplish the same job, can have significant differences in the life, and sound of gears. Backlash, torque, composition of the gesrs can make tremendous differences in the life of gears. So even though the two dials appear to have the same components just arranged differently. One may work, and last, the other may work, and fail quickly.
D/P

[paul-f]

I believe the Number 6 dial actually came out AFTER the #7.  It was announced 8/1/52.

[JorgeAmely]

Paul:

Can you comment on the 7A and 7C? Most early 500s had the A version, but it seems to me that anything later than 53 had the C version of the dial.

[paul-f]

Jorge,

I'm away from my library, so this is from memory, with a little help from my site.  

The 7D dial came out in about 1953 and replaced the 7A.

As everyone looks at their dials, let us know the latest 7A and the earliest 7D you find with dates in 1952 or 1953.  Let's see if we can pin it down.

    Latest 7A : 10/52       << Note: Updated
    Earliest 7D: 8/53

The 7C was used on the colored sets (also starting in 1953), and was the same as a 7D, but with a plastic fingerwheel.

(What happened to the 7B?)

[Dan/Panther]

I would like to compile an album of all known dials in the 500 series. I know this could take some time, but with help from everyone It could go much quicker.  Would it be better to have as many angles as possible or just like the samples.
Not only be year but if possible month by month.
Here are 4 examples of how I would like to feature them.
D/P

[Jim Stettler]

Stan's Swiharts Dial book is supposed to come out this month. It has been delayed for 2-3 years because of additional info Stan was wanting to add.

I have a copy on order. It will be interesting to see what Stan says.
Jim

[Dan/Panther]

Jim;
I forgot about Stan's book. I guess I don't need to make a list.
D/P

[Jim Stettler]

Jim;
I forgot about Stan's book. I guess I don't need to make a list.
D/P

A list is still good. Stan's book should help with the timeline, and Paul F. still is researching dates.
Carry-on,
Jim

[zuperdee]

Interesting--as I look at the pictures Dan/Panther has posted, you can clearly see the progression in the #7 dial's evolution! The prototype dial clearly has a wider footprint than the official #7 dial that finally made it into production.

Furthermore, if you look carefully, you'll notice that the mechanism frame is mounted to the face frame with screws. Later, on the official #7 dial, you'll notice there is an empty screw hole right around the place where the mechanism frame of the prototype dial was originally mounted!

I consider this as evidence that Western Electric might have tweaked the prototype dial mechanism to make it more compact before production because they were starting to realize they could use it in both the 500 sets AND earlier sets that needed a 3" dial like the 302. Really, the mechanisms of the prototype and #7 are not that different when you think about it.

To my untrained eye, the #8 and #9 type dial mechanisms look virtually identical to the #6 and #7. The #8 dial obviously came first, and was designed for phones needing 3" dials like the Princess phone, the 750, and the 1654. This dial is also designed for mounting to the body rather than the housing.

The #9 dial followed, and was identical to the #8 dial, and used exactly the same mechanism, only for the #9 package, the mechanism was riveted to a slightly larger stamped steel face frame for use in the 500 sets.

I am willing to bet that one could probably make a #8 dial work in a 500 set by drilling out the rivets holding the mechanism to the face frame, then riveting it back onto a face frame for the 500 set, and vice versa!

[Dan/Panther]

If you take a look at my dial, and Paul's dial, then look at the photo, basically the only real difference is the location of the two components that basically doesn't alter the functionality of the dial a bit, but like Zuperdee says, makes the 7A's footprint small enough for future needs.
D/P

[Kenny C]

I know I a draging up an old topic, but, A new member I met over facebook just joined and his username is "beaver 3125" and He has a 7A dated 5-53. I am sure he will post a photo of it.

[GG]

Thanks for reviving the topic. 

I used to think a 7A was only the type shown in the bottom picture in Dan's series of pictures, shown dated 10-52. 

However I just picked up a 501 set in very rough condition, dated 4-52, which is a classic Bell mongrel: 1950 housing & transmitter through 1958 ringer.  The dial is a 7A dated 6-51 with reverse-painted numberplate, and looks exactly like the next-to-last of Dan's photos, the one that's dated 2-51.

The governor on the '52 version uses thicker (heavier) weights and a simpler return spring than the '51 version.  The '52 version has a different shape of impulse contacts, with the little extra tab at the top, and does not need the extra metal stop that's screwed to the gear frame.   And the contact assembly is a slightly different style of moulding. 

IMHO the #9 is a whole different animal.  The major change from the perspective of servicing the dial is the riveted gear assembly and the location of the governor spring.  On the #7, the governor spring is easily accessible and can be tweaked gently to adjust the dial speed if needed.  On the #9, it's basically inaccessible and can't be adjusted: you'd have to break out the rivets and ...uh-oh.  A #7 can be disassembled, cleaned manually, and reassembled.  A #9 can't.  So while the #9 is an improvement in certain ways (e.g. quieter), the inability to disassemble, clean, and adjust is a step backward. 

I don't think The Bell would have thrown away #9s that had trouble.  Instead they would have gone back to WE where they would have accumulated until there were enough of them to justify a production run to break them down into parts and rebuild them again.   

OTOH, how many of us have seen a damaged or nonworking #9 dial?  I can't recall ever changing one out for repairs, including the ones on ITT and SC 500s that we had in large numbers in PBXs in the 80s.   I can't recall ever having seen one that was nonworking, anywhere, and they've now been around for over 40 years.  So that certainly says something about quality.  Hmm...