Classic Rotary Phones Forum

Telephone Identification, Repair & Restoration => Telephone Troubleshooting and Repair => Topic started by: twillkickers on May 04, 2021, 11:46:24 PM

Title: Can't get AE40 with 66 Hz ringer to ring
Post by: twillkickers on May 04, 2021, 11:46:24 PM
See attached photos. The coil on the ringer says use 1MF condenser, but the condenser says .7 MF and 4 MF on the side. Was the wrong condenser installed in this phone? It does not ring when I run a 66 Hz ring to it through my VOIP box (Obi 202), but I can see the clapper vibrating. I have a similar AE40 with a 33 Hz ringer and it rings fine when I send a 33 Hz ring. In addition, how do these square condensers work? Are there two different capacitors inside? How do I tell which terminals to use?

Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: RB on May 05, 2021, 12:40:14 AM
Try moving the gongs closer to the clapper. :)
The cap looks odd to me??? ???
usually, both wires on a cap are the same color.??? 2 red, and 2 grn.
it appears yours is using the grn wires for the ringer.
That should be fine.
Yes, there are 2 caps in that 1 box.
Convention says, the 2 oval holes should be 1 cap in each.
Or, top and bottom, maybe.
yours, however, seems to be wired cris cross???
The values, should be ok???
your gonna have to consult the schematic to be sure.
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: HowardPgh on May 06, 2021, 01:51:25 PM
On the square AE double capacitor the wires at the top are one value, the ones at the bottom are the other value.
Some AE 40s come with 2 separate capacitors.  The higher value (4 MF) capacitor is for the talk circuit.
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 06, 2021, 08:55:33 PM
Quote from: twillkickers on May 04, 2021, 11:46:24 PM
See attached photos. The coil on the ringer says use 1MF condenser, but the condenser says .7 MF and 4 MF on the side. Was the wrong condenser installed in this phone?

I don't know why there is a discrepancy - perhaps it is a refurbishment issue (ringer frequency changed).


Quote
It does not ring when I run a 66 Hz ring to it through my VOIP box (Obi 202), but I can see the clapper vibrating.

The ringer might be too big a load for the ATA. Can you measure the ring voltage? It will have a DC offset which you can see on a CRO but an AC measurement would do.


Quote
I have a similar AE40 with a 33 Hz ringer and it rings fine when I send a 33 Hz ring.

Your 33Hz ringer requires less voltage to ring but the main thing is that it is a much high impedance ringer. It will not load the ATA nearly as much as the 66Hz ringer.

Regards
Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Babybearjs on May 06, 2021, 10:30:22 PM
the ATA is set to 20HZ for the ringing voltage, that's why it won't work... I'd just change the ringer to a straight line ringer... party line ringers are a hassle!
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 06, 2021, 11:08:06 PM
Quote from: Babybearjs on May 06, 2021, 10:30:22 PM
the ATA is set to 20HZ for the ringing voltage, that's why it won't work... I'd just change the ringer to a straight line ringer... party line ringers are a hassle!

He changed the ATA to 66Hz.

Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Babybearjs on May 07, 2021, 01:13:00 PM
ok, then it could be the amperage, or the bais spring... or just a bad coil... I don't mess with AE parts anymore, so good luck fixing it...
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Key2871 on May 07, 2021, 01:56:24 PM
Its obviously a case of using a frequency ringer instead of a straight line ringer. Straight line ringers operate on 20 to 30 hertz, that's it.
You might get a tinkle out of it once and a while playing around with adjustments, but I don't think it's worth even trying. As Jack said replace the ringer with a straight line ringer.
I've even tried with an ITT ringer once to no avail.
I just changed the ringer.
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: twillkickers on May 07, 2021, 11:23:25 PM
For science's sake I'm going to try this with a 1 microfarad capacitor to see what happens and report back. I can change my ringing voltage on the VOIP to 82V but this didn't make a difference. Default setting for ringing voltage is 70V works fine for the 33Hz ringer.

Does anyone know if it is really possible to modify the ringing frequency of a frequency ringer just by changing the capacitor? If so there a way to calculate which capacitor to use?

I also checked the existing condenser/capacitor by putting my capacitance meter across the leads as HowardPgh instructed (thank you for that input!!) and this capacitor seems to be in working shape! (See attached photos)
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: RB on May 08, 2021, 04:00:25 AM
Howard's quote:
On the square AE double capacitor the wires at the top are one value, the ones at the bottom are the other value. "Thanks for clearing that up! ;)
Your caps are adequate for this situation. Put them back in, and move on.
No, you can't change the freq by just changing the cap. The AC goes straight through.
You have a power problem, not a freq problem.
Jacks quote:
Your 33Hz ringer requires less voltage to ring but the main thing is that it is a much high impedance ringer. It will not load the ATA nearly as much as the 66Hz ringer.
TK, you are trying to use a DIGITAL solution for an ANALOG problem. That is NEVER the best way to solve complex problems. "And it is expensive, too!
If you are bent on using that ringer, then get yourself a 66Hz ringing plant. good luck on that one.
Alternative solution:
Jump on ebay, and get yourself a SL ringer. no one will care that you have changed it, and your headache will go away.

Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 08, 2021, 05:00:07 AM
Here is a 16.33 Hz frequency ringer in an AE 40.

The circuit is pretty much the same as yours and the ringer type (impedance) is the same as yours. Frequency ringers are resonant at their operating frequency - the resonance is electro-mechanical meaning that it is achieved with a combination of circuit elements - the capacitance of the ringing capacitor and the inductance of the bell motor - and mechanical elements. The mechanical elements are the spring mount that is used as a clapper pivot and the mass of the clapper itself.

Notice the size of the clapper in this bell compared with yours. The clapper is heavier to slow it down and help bring the resonant frequency down. If you see this as a challenge and want to experiment, try making a larger clapper.

Good luck.

Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: countryman on May 08, 2021, 07:33:04 AM
I have zero experience with dedicated frequency ringers. The ringers I have dealt with were mostly European models designed for nominal 25 Hz ringing. But most any of them would ring with a slowly cranked magneto (~15 Hz) and 50 Hz from a mains transformer or most consumer grade PABX "here" as well.
Sure the frequency ringers were tuned to ring with the right frequency exclusively. But there should be some kind of reaction even when either the ringing power is low or the frequency is not 100% correct.
Maybe the ringer has a different problem, like a binding pivot or a weak magnet.
Have you tried ringing it with for example 24 V AC from a mains transformer? Some types of incandescent Christmas lights use 24 V AC.

To me it also seems possible that the ATA mentioned indeed can be set to 66 Hz, but will not be really efficient with this setting. Few people would ever notice this type of design flaw.
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: poplar1 on May 08, 2021, 04:30:57 PM
A frequency selective ringer, by definition, should ring only when the correct frequency is applied!
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: dsk on May 09, 2021, 09:49:38 AM
The capacitor should be as close as possible to 0.7 uF, but I guess that 1 is close enough. The frequency of a 66Hz ringer should of course be 66 Hz as you have adjusted the ATA to give, so so far all is good.  If it is possible to adjust the distance between the clappers magnetic "poles" and the coil the maximum movement should be quite short so the clapper will not be able to move more than around 5mm. (3/16")
Then the gongs should be turned to be close enough to be hit by that movement.  When you get it moving try to adjust the clapper out and in to get max force on the ringer.

Good luck!
dsk
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 09, 2021, 11:34:05 AM
Quote from: dsk on May 09, 2021, 09:49:38 AM
The capacitor should be as close as possible to 0.7 uF, but I guess that 1 is close enough. The frequency of a 66Hz ringer should of course be 66 Hz as you have adjusted the ATA to give, so so far all is good.  If it is possible to adjust the distance between the clappers magnetic "poles" and the coil the maximum movement should be quite short so the clapper will not be able to move more than around 5mm. (3/16")
Then the gongs should be turned to be close enough to be hit by that movement.  When you get it moving try to adjust the clapper out and in to get max force on the ringer.

Good luck!
dsk

Hi Dsk,

A frequency ringer does not have a pivot like a straight line ringer so the adjustment you suggest is not possible. Instead of a pivot, there is a piece of spring steel that, in combination with the length and mass of the clapper, form a mechanical resonant system. That, in combination with the inductance of the bell motor and the capacitor form an electromechanical resonant system at 66 2/3 Hz.

I think that the load is too great for the ATA at 66 Hz. That is why I suggested changing the mass of the clapper in an attempt to bring the resonant frequency down to 16 Hz.

Regards
Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: dsk on May 09, 2021, 12:19:21 PM
I know that, and I did bend on mine to get it closer. that helped a little. Just turning the bells will also help, and more mass on the clapper will lower the frequency. I do not know how much the stiffness of the spring will be of importance but may be not to much?

dsk
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: TelePlay on May 09, 2021, 05:42:46 PM
Trying to physically modify a frequency (reed, not pivot) ringer has been discussed on the forum in the past. These are two topics that may give you ideas, two different ways suggested by members some 10 years ago that I remembered reading back then. There may be other topics, the search function worked good enough for me to find these.

http://www.classicrotaryphones.com/forum/index.php?topic=5601.0

http://www.classicrotaryphones.com/forum/index.php?topic=6047.msg72088#msg72088

This is all individual trial and error experimentation so whatever works for you works. I've never tried such modifications.
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 09, 2021, 08:14:50 PM
Quote from: dsk on May 09, 2021, 12:19:21 PM
I know that

OK, sorry about that.

Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: Jack Ryan on May 09, 2021, 08:25:50 PM
Quote from: TelePlay on May 09, 2021, 05:42:46 PM
Trying to physically modify a frequency (reed, not pivot) ringer has been discussed on the forum in the past.

Yes, there are lots of suggestions, many of them destructive. The spring for 66Hz may be just too strong but I was making non destructive suggestions just in case they might work.

My suggestions are only theoretical though because I don't modify them. Some are used on simulated party lines and others are simply historical artefacts.

Jack
Title: Re: Can't get AE40 with 66 Hz ringer to ring
Post by: TelePlay on May 09, 2021, 10:06:50 PM
Quote from: Jack Ryan on May 09, 2021, 08:25:50 PM
Yes, there are lots of suggestions, many of them destructive. The spring for 66Hz may be just too strong but I was making non destructive suggestions just in case they might work.

The second link I posted was a non-destructive option involving the loosening of a screw. Never tried it and don't have a frequency ringer at hand to try that now.

The best fix is to replace the frequency ringer with a SL ringer.