42 cycle ringer to ring on 20 cycle system

[Dan Schafer]

Hi All
New to group & will surely have many more questions down the road.  Just wondering...I have a North Electric rotary dial rectangular base desk set that is for a 42 cycle ringer.  Is there a way to get it to ring on my 20 cycle system or some other suggestion? I like the sound of the old mechanical bells.
Thanks in advance.
Danny in Cleveland

[paul-f]

After so many years have passed, the first thing to do is check to make sure the ringer in the phone is the same as the marking on the base plate.  There's some info on North H series set ringers here...
   http://www.paul-f.com/NorthRingers.html

A 42 cycle ringer should be marked H-224-H or H-224-HH.  If that's what's in there, the best fix is to replace it with a straight line ringer.  A 20, 25 or 30 cycle ringer. may ring as well -- but may not achieve its optimum sound.

Some have had luck tweaking ringers designed for other frequencies by attempting to change the mechanical characteristics (spring stiffness, clapper weight and weight position) and the value of the capacitor.

If you're not a purist and can't find a North ringer, you can substitute other styles of ringer.  There's a lot of room in there and most ringers have similar enough electrical characteristics to work.  If you go this route, it's generally best to figure out a way to mount the replacement ringer that doesn't involve drilling new holes.  That way the phone can be restored to original condition in the future, if desired.

[JorgeAmely]

Dan:

This is a photo album of a Galion into which I added a Trimline ringer because the original 42 Hz ringer would not ring. No drilling required, so when you find a straight line or 20 Hz frequency ringer, all you need to do is a quick swap.

http://picasaweb.google.com/Amelyenator/Model8H6FromNorthElectricCompanyFromGalionOhio#

Good luck and welcome to the forum.

[Bill]

So I think the idea is to take the incoming 20-cycle ring voltage, and use it to ring a 42-cycle ringer. Has anyone tried connecting a fullwave rectifier in the input side of the ringer? It would produce a 40-cycle waveform, though highly distorted. I'm not sure that a ringer cares about distortion.

The rectified wave will have a substantial DC component, which would have to be removed with a series capacitor - but doesn't the phone already have a series capacitor in the ringer circuit? Since the existing capacitor is sized big enough to pass 20 cycles, it ought to pass 40 cycles really well.

Just a thought - I certainly have never tried it - but it might provide enough power to tinkle the ringer. It is really easy to try, and Radio Shack has bridge rectifiers for well under $2 ...

Bill

[Phonesrfun]

Bill: Try it out.  I would be interested to know the outcome. 

As I see it, though, 42 cycles is only one of about a dozen or so possibilities in frequencies, so what about all the 30 cycle, 33.33 cycle, 50 cycle, 66 cycle, etc ringers? 

Also, a full wave rectifier would, in fact produce 2x the frequency, in this case 40 cycles, (may be close enough to 42), but the rectified voltage would be half the voltage as measured from the base line to the peaks; rather than peak-to-peak as with full AC, so I am wondering if that would be enough excitement for the riner.