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#7A Dial revisited.

Started by Dan/Panther, June 02, 2009, 10:14:03 PM

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Dan/Panther

I would like to direct this to Dennis, as I used his photo, but anyone else with info feel welcome to chim in.
I posted that the center spring and dial finger wheel mount, had come off of my number 7A dial,  while cleaning, and I wanted to know how to properly put it back.
I found the following photo which has the same components as I was referring to.
At number 1, you can see the end of the spring I mentioned, and at photo 2 you can see the indent I referred to. At the bottom of that indent are 4 grooves located 90 degrees apart, one of which the end of the spring goes in to.
My question was, which groove do you put the spring into, and howq many turns do youy preload the spring. Different indents will give different results, for a given number of winds of the spring, and if you do not have the proper groove, and spring preload, the end of the spring will pop out of the indent. I tried several combinations, and finally got the dial to return at a constant speed, and the spring did not pop out of the indent. I just wanted to make sure I have the propoer preload and spring in the proper indent.
The way I have it now, the dial takes a little more than a second, about 1-1/4 seconds to return which is slightly slow.
D/P

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

JorgeAmely

I pre load mine two turns, because while remove the spring tension, I counted two turns to release all the tension. My 2 cents.
Jorge

Dennis Markham

Dan, I don't recall what the 7A dial looks like around the hub.  The 7C and 7D dials have only one indent for the spring tab to fit into.  So I cannot answer your question. Although I have taken apart a 7A dial, as I said, I just don't remember that aspect.  I do have a 7A dial not in use.  If you would like I will tear it down and see where that spring is seated.

bingster

Some older dials are like this, too.  There are several places for the spring to seat.  With those, I seat the spring in whichever notch will allow enough tension to cause the fingerwheel to return quickly when a low number is dialed, but not so much tension that the dial becomes difficult to turn when dialing a high number. Finding the "right" position is just a matter of trial and error.

In short, I don't think there's a specific place for that spring to go.  I think rather, there are several places to seat it, so that it can be placed wherever it will give the best result.
= DARRIN =



Phonesrfun

Yes, I think the reason for the multiple notches was just that.  Springs are not all the same, and they also weaken over time.  Two turns is about it.  The specs for the pulsing of a dial are 10 pulses per second.  Therefore, it should take about 1 full second for a dial to return when dialing a zero.  The real speed regulator, however, is not the tensioning of the spring as much as it is in the setting of the governor, which is a different topic altogether.

-Bill
-Bill G

Dan/Panther

I hit upon what Bingster points out, that trial and error will find the right position. Now I quess my next step is what phonesrfun points out the governor might need an adjustment.
Jorge, thanks for the confirmation of two turns that is what i ended up with. As far as the indents arew concerned the two farthest indents, thye spring popped out after about 1-1/2 turns, and the closest, the dial would not return after dialing 1, the second indents works full swing with 2 turns of the spring, but like I mentioned it's about 1/4 second slower.
Now can anyone run through the governor adjustment  on a 7A dial.
At this point the dial functions correctly, however it does take about 25% longer to return. It may not effect the dial function in operation.  I have not yet finished the phone to line test it yet.
Dennis, BTW, the problem with the cursor jumping has stopped.
D/P

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson

rp2813

Dan, I've read here about adjustments to governors but I'm not qualified to provide any advice on that.  One thing is certain:  that is going to be a sweet-spinning dial when you're done.  What's it belong to?

Ralph
Ralph

JorgeAmely

If the return time is off my a little, I may just leave it alone. Long time ago, the dial timing was critical because electromechanical components were changing states as the dial returned. These days, the digit decoding is done by computer software and it is more tolerant to deviations from the original standard.
Jorge

Dennis Markham

I don't have any experience with adjusting the governors on the 7 series dials.  I have done some adjustments on the older #4's where it is much simpler.  There is a tool that was used to tighten or loosen the spring on the governor wheel on those dials, and later dials.  I have wanted to get one but have not.  I'm sure you can figure out how to make the adjustment by shortening the spring.  I've never taken the time to play with one because as Jorge said, if it was close it was good enough for me.

BDM has told me that with his cable-based phone system he has had to speed up his dials a tad in order to get them to work properly with each digit of the dial.  I have a POTS line and my dials all seem to dial properly even if some are slower or faster than others.

rp2813

The same is true for my POTS line.  Between my #4, #5's and #7's the return speeds can vary but the call always goes through. 

Ralph
Ralph

Phonesrfun

My cable-based Vonage router is extremely picky about dial pulses.  I think the idea that modern electronic computer based central offices are more flexible may only extend to phone company central offices that have been in the business of supporting rotary dials forever.  The routers that the VOIP services use were probably designed by an entry-level engineer right out of engineering school who has never even seen a rotary dial.

Adjusting the governor on a #7 I believe involves a pair of needle nosed pliers and the two springs on the governor.  The springs need to be bent SLIGHTLY to achieve the needed change, and since semantics can be difficult, I won't go into a lot of detail.  Over all to speed up a dial, you want to tighten the springs so they do not allow the weights of the governor to fly out as much.  The idea of the governor is that when the weights fly out against the barrel that they reside in, there is drag created to slow it down.  The more drag, the slower the dial.

All that being said, the real test is whether it works or not.  Even though a dial that is perhaps 25% slow can be annoying to the user, if it works and does not mis-dial, then I would not go messing with it.  After screwing up a dial or two, one kind of gets the hang of it.  If you don't have a spare that you can experiment with and it works, leave well enough alone.  If it is mis-dialing, I would consider sending it off to Steve Hilsz.

-Bill
-Bill G

Dan/Panther

I'm thinking it may work properly.
It's just annoying as hell to have 50 dials that are all very close, and one slow one....

I'll leave it as is until I test it, so far all have worked, so no reason to think this one won't.
Thanks all.
D/P

The More People I meet, The More I Love, and MISS My Dog.  Dan Robinson