9H Dial extra contacts

[Dan/Panther]

I have this 9H dial below I took out to clean it, when i found it had an extra set of contacts and wires. They were taped off, but what were they for.
D/P

[paul-f]

The most common use is to mute an attached speakerphone during dialing.

[keysys]

From the Bell System Practices, Section 501-162-101 - Issue 5 - December 1967- Table B:

"Has two pair of off-normal contacts designed for speakerphone systems.  Also used on 532-, 533-, 535-, and 536-type telephone sets.  Replaces 7E, 7G, 7H."

The extra set of contacts via the two yellow wires mutes the speaker during dialing.  Without this arrangement, dial pulsing clicks would be passed to the speaker and would be broadcast at obnoxiously loud level.  Similar to the two white wires which prevent pulsing from being heard in the handset's receiver unit.

[Jim Stettler]

Extra contacts are for extra feature, are they normally open or Closed?
You can probably use this dial in a set where you may need the extra contacts. Speakerphones and magicall dialers are the first that come to mind.

Jim

[keysys]

In the 9H dial, contacts are normally open.  The extra contacts in the 9P dial are normally closed. 9P dial is intended for use in the 529B telephone set, according to the previously cited BSP.

[Dan/Panther]

O.K. I've got another problem with the dial.
When I put the dial into a circuit, I can pick up the receiver and only get a barely audible dial tone, when I lift the receiver it breaks dial tone, and I can dial, problem is I can't hear anything or say anything.
Upon looking at the dial closer I found something I'm thinking may be the problem.
I'm assuming when at rest the cams marked #2 , should hit the contact levers at #3 & #4. opening those contacts. The contacts at #1 work normally when dialing.
The levers don't appear bent, and i see no way to advance the cam. Shouldn't those contacts be open when the dail is at rest, and is it proper to bent the levers to make this happen.

D/P

[Phonesrfun]

The contacts for the white and yellow wires are supposed to be open while the dial is not being rotated.  Their purpose is to close and short out the receiver during dialing so that you don't hear the popping while the line is being pulsed by the pulsing contacts.

Something has forced that gear that has the cam to be out of alignment.  Maybe someone took the dial apart, gears and all, and did not get that main gear back in the proper "home" position, or maybe it just jumped a cog.

[Dan/Panther]

Bill;
What I did was take the contact bank off, and switched it with one from another dial without the extra set of contacts. It seems to work O.K. now. I'm a bit confused that the other set of contacts worked, where the originals didn't. I felt like you, that maybe the gear was not in time.
D/P