Dials: test and interpreting test results.

[dsk]

Hi,
I starts this test to see if it is possible to guide someone, to make good tests of the dial pulses, and even interpreting test results.

Its convenient when Haf has problems with his AE 21 with a dial who tries to let him learn new people to know.   IA very social dial, but sometimes.....

First of all we need a setup, and he will probably need some time to solve this.
The picture is just a hint of how it can be done with a minimum of equipment.

The goal is to end up with something like this:


dsk

Edit: Even simpler diagram:   
dsk 10/3-13

[Haf]

you mean something like that

Dial candlestick is, like the name suggests, the dial from the candlestick, dial 1 is another one from a 21 wall phone.

[Haf]

I just want to ad a picture from my "professionally" test set-up, lol..and yes I know scotch tape is not first choice of connecting cable tails
But if it works, it will do.

Haf

[dsk]

 
It is a little complicated with the signal level not delivering a constant tone, but I guess the result still is more than good enough. A little job to determine whats break and make.

The picture here:

[Haf]

I'm not really good in interpretation ... what does it say?

Haf

[dsk]

Now we have to measure a little, at the screen, or print it out and measure on the paper.
Closed pulse contacts are marked as red line.
The yellow line indicates the total length of 9 breaks + makes
The pulses looks similar for all 10 breaks, so just measure one, The candlestick gave me a ratio of 5/17 (make of a total make+break)  5.2/17x100 gives 30.6%  9 pulses (make + break is the length of the yellow line and is done at a time of 0.87 sec.  9/0.87= 10.34 pulses pr sec.

The same calculations for Dial 1 makes the ratio=32.4% and exactly 10 pulses pr sec.

Conclusion:

Speed are quite near the standard of 10 pulses pr sec. 8-12 are usually OK, When we tune it we use to get at 10-11 so the speed are perfect.  

What about make break ratio, first thing, we cant adjust this easily. It is different standards and the exchanges should actually read all, 30-40% should be OK  
(USA and Norway use 40/60 as a standard. UK ++ uses 33.3/66.7)


dsk

[dencins]

It is a little complicated with the signal level not delivering a constant tone, but I guess the result still is more than good enough. A little job to determine whats break and make.

I use a different set up that measures the break of the contacts using Zelscope so it does not need a sound source.  It simplifies the test.  You can see the set up here:

http://www.classicrotaryphones.com/forum/index.php?topic=2387.0

I do not bother with the peaks since the approximate ppm is close enough for me.

Dennis Hallworth

[twocvbloke]

I found a silly-simple way to test, doesn't require the removal of the dial, just hooking the phone up to the Mic. port, using an appropriate interface, and using audacity to record it...

http://www.classicrotaryphones.com/forum/index.php?topic=6216.msg76263#msg76263

Speaking of which, I need to do that on a few of my GPO phones, they don't sound right...

[Haf]

So, if I understand dsk right, the speed is within normal parameters, something I supposed by stop watch speed test. What else could cause the incorrect dialing?, I have this problem with all my AE dials, none working correct but never had any problem with WE dials, even not the 2ab? (it's not marked at the fingerstop but looks alike and has that quite loud mechanically clicking sound when dialing) stored for more than maybe 50 years gambling with dust and moisture.

Haf

[dsk]

This is a new problem for me.
So now we have to start the guessing.
If we adjust the little we are able to of make brake ratio it may do a difference, or it may not.

We may analyze a W.E. dial you have as known working dial to compare, or just start adjusting to come even closer to the 40/60 ratio.

To adjust the dial I pictured slightly bending the tab in the direction the arrow points, but not so much that it doesn't open (brake).

dsk

[HarrySmith]

The easiest way I have found to repair a dial is send it to Arizona

[AE_Collector]

If you weren't in Florida Harry, I would guess that the heat of Arizona warms it up and helps it relax so that it is ready to go for at least another year when it returns home?

Terry

[Haf]

To compare, this is a working  5H WE dial from 1943.

[dsk]

Then we ends up with this:

[Haf]

What should that say to me, I'm again confused.

Haf