Ringer Not Working Properly

[BigBird0000]

I have what was identified as a Swedish American phone.
I am trying to get the original  ringer to work.
For testing, I have it attached it to a Tellabs 8050 ring generator (20Hz)
The detent in the "pivot" is correctly aligned, and the clapper moves freely.
The clapper moves if I hold it a little to one side.

The coil winding are fairly well matched, about 510 and 530 ohms each.
Does anyone know how I can fix the ringer to it will work?

I have the video at  https://photos.app.goo.gl/ob33KBrhpyKENry58 (had a problem uploading to this forum)

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Moderator Edit: screen capture of ringer in video added (Note: videos and audio files can only be attached to a post or reply if first put into a zipped folder.

[Sargeguy]

Are there any adjustment screws in the base of the armature that would prevent the clapper from moving all the way?  Maybe a hole for a screw?

[Key2871]

Is it a 20hz frequency ringer, or is it different because of where it originates from. Or is it a frequency ringer.

[BigBird0000]

I'm not sure. It has no special markings on it, so I really can't tell for sure.

[Sargeguy]

is it different because of where it originates from.

Swedish-American Telephone Co. was based in Chicago.

If there is no bias adjustment screw, maybe the armature is crooked?  Something is slightly out of alignment. You may also want to try tightening or loosening the screws that hold the coils to the armature.

[TelePlay]

     Regular Member Post

It might be as simple as seeing how it works with the clapper between two gongs, letting the gongs control the movement of the clapper keeping it from going too far to one side and being captured by one magnet coil.

This is an old, unbiased ringer (no spring) so I would try it with it installed between the gongs and adjusting the gong distance to the clapper to get the best striking pattern.

Princess and Trimline phones rely on the gong stopping the clapper from moving too far from the aramature plate causing those ringers not to work, something I have discovered on the Princess (forgot the number, M-Type) and Trimline P1A ringers.

Your finger in the video is acting like a gong, I can do the same with a P1A ringer with the gong removed, let my finger impact the clapper and that makes it work just fine just as your ringer seems to do with your finger in place.

[Sargeguy]

Did you test it using a magneto?

[BigBird0000]

Sareguy & Teleplay,
I tried moving the gongs earlier. Not enough to get the clapper going. Maybe I can use a washer remounting the ringer to give me enough offset to get the gongs to be in position.
I'm going to do that later today, I need some #12 machine screws to hold the magneto,
It looks like the armature may have been bent in the past, so that is a hint.
I'll let you know what happens.

[BigBird0000]

The ringer worked with the magneto. I was not able to get a frequency reading with my meter on the magneto.
Since I plan on having the ringer work with the magneto or the POTS (not at the same time),
I put a shim in 1 side of the ringer, and with that, I was able to move a gong to keep the clapper from going to far on one side.

[Sargeguy]

In general an unbiased ringer is used in local battery applications and a biased ringer (with a spring) is used in common battery applications.

[BigBird0000]

I have attached a picture, It shows a washer as a spacer.
This has the effect of moving the clapper closer to one of the gongs - close enough so the gong
can keep the clapper closer to the center of travel, so it works for magneto and regular telephone
(I do have a ring voltage booster from sandman on the line, and I haven't measure the REN.)

I have attached a PDF that shows an exaggerated view of what I did