ITT(?) 500 ringer issues.

[jkpenrod]

I have a 500 phone from 68 that may be ITT, at least it has an ITT body. Anyway, the ringer is not working and I can not tell if it is because I have the wrong ringer, have it wired incorrectly or if it is just a bad ringer. It waswired with the red wire to L2 (Toward the dial), Grey to K, Grey/red to A and Black to L1. I am including some photos of the ringer so you can see whAT I am working with. Is it the ringer or the wiring? If it is the ringer do i need to just buy a  one?

Thanks for the help.

[unbeldi]

Your ringer appears wired correctly, but your ringer is a frequency selective ringer for use on party lines.  It was very common, in the networks of the independent telephone companies, to use frequency selective ringing, so that up to 10 parties could be rung on a line without disturbing everyone. For this the ringer has one of a set of five resonance frequencies.
Replacing replacing frequency ringers is a favorite sport of collectors, therefore.  Unfortunately, because the sound of a 40, 50, or 60 Hz ringer is an added collecting experience.

The most distinctive feature of frequency ringers is the weight on the clapper.  Heavy weight = low frequency, small weight = high frequency.
See here for a comparison chart:  http://www.classicrotaryphones.com/forum/index.php?topic=11938.msg126866#msg126866

A standard telephone line today uses 20 Hz ringing current.  This type of ringing is called straight-line bridged ringing.

I had to lighten up your picture a little to see the details on the ringer.  You have an HB2 type ringer, which has a resonance frequency of 42 Hz.  The 42 is also stamped on the ringer next to the code.

The frequencies on a party line in the synchromonic system are 16 Hz, 30 Hz, 42 Hz, 54 Hz, and 66 Hz.

Sometimes it is possible to detune the frequency of the ringer to ~20 Hz, but I doubt you will get this one down that low.

You have these options:
* Do you really need another ringing phone?
* Replace the ringer with a standard C4A ringer from another set, should be easy to find
* Get a ringing power supply that outputs 42 Hz.  There are VoIP ATAs that can actually do this, such as Linksys PAP2, if I recall correctly.  This is the best collectors' choice, IMHO.
* Get an external add-on ringer

[jkpenrod]

Are there any markings or anyway for a novice to correctly identify a C4a ringer?

[unbeldi]

Are there any markings or anyway for a novice to correctly identify a C4a ringer?

The C4A ringer is the standard ringer in almost all Western Electric 500-series telephones.
It has C4A stamped on the frame of the ringer, between the coil and the gong, along with the date.
See this picture...
Later in the 60 and 70, the type was often punched into the metal, rather than applied in ink, but it is always in this vicinity, sometimes on the other side of the magnet core.

[david@london]

unbeldi -

i have a 500 from 1958 which has the numbers punched/moulded into the ringer. unusual ?

[unbeldi]

unbeldi -

i have a 500 from 1958 which has the numbers punched/moulded into the ringer. unusual ?

Seems like I have seen that too.  Is this a Northern Electric ringer?

[david@london]

no, western electric.

[unbeldi]

I think, all metal version of the date mark use only the quarter, and not the month, like the ink stamps.  I have to sort through my data to find a transition, if there was one.

Here is another one:


PS: on quick searching my catalog, I found a few:   III 58, III 59, IV 59, III 60, III 60, I 62, II 62, I 63, I 64, II 66.
I don't keep much of the 1960's stuff though.

So it seems...  this started perhaps in 1958, but not all ringers were marked this way. There also seems to be a slight change in frame design for these. Perhaps they made these in a different location.

[jkpenrod]

Okay I have another ringer I am having a hard time getting an ID on. It is from a Stromberger-Carlson. It has 12WM stamped in it, which you may be able to see in the photo. The interesting thing to me is that the Grey and Grey/red wire were not connected to anything. Is this another party line ringer?

[poplar1]

Slate (gray) and slate-red were normally not used on these frequency selective ringers, which were installed for certain party lines. There is a capacitor mounted on the ringer. This capacitor was used rather than the  capacitor Inside the network,  which is  designated A and K.

The original ringer in this post also would not have used the slate or slate-red conductors.

[unbeldi]

Okay I have another ringer I am having a hard time getting an ID on. It is from a Stromberger-Carlson. It has 12WM stamped in it, which you may be able to see in the photo. The interesting thing to me is that the Grey and Grey/red wire were not connected to anything. Is this another party line ringer?

Yes.

The reason for the condenser directly on the ringer is that the capacitance needed to be changed for each frequency to tune the electrical resonance frequency of the combined circuit (capacitor + ringer coil). The value of the capacitor had to decrease with increasing frequency. For example at 20 Hz, a capacitor of ~500 nF (0.5µF) was used, which decreased to ~200 nF at 30 Hz, all the way down to ~50 nF at 66 Hz.

In ringer design it is important that the mechanical resonance of the clapper is agreement with the electrical resonance of the circuit so that the ringer wastes as little energy as possible.  If the electrical resonance is off, it takes more energy to move the clapper.  At the point of resonance, the ringer consumes the least amount of electrical energy for useful work, and has the smallest electrical impedance.

Your 12WM is a 54 Hz ringer,  the M indicates the frequency. Each manufacturer had a different coding scheme. The capacitor on this ringer is probably approximately,  0.07 µF, or 70 nF.  The value should be printed on the yellow cover.

[jkpenrod]

Thanks to everyone who has been responding to this post. Unbeldi and Popular1 I truly appreciate the level of information you have given me. While I realize that the questions I have asked are much more basic than the information you have provided, my career as and engineer and my hobby with electronics as a youth begs the answers you have provided. Your answers have gone above and beyond simply answering my questions, but rather providing a level of understanding of how these things work. That knowledge goes a long way to helping me to better identify these things in the future on my own and helps me understand how to resolve the issue.

Thank you so much!

[unbeldi]

Glad to hear that, thanks.