atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems 1A2 and some old WECO stuff

Bell tap is a recognized telephone industry trouble term that has been around since the beginning of dial service. It refers to the fact that if the ringer and its associated network (and subscriber loop) are not set up correctly, when the switch hook is operated, or the rotary dial is used, the ringer will follow the opens/closures of the loop, making a tinkling sound. It can be cured by adjusting the bias spring, reducing the capacitance of the loop, and a few other things.

The other concept that seems to have gotten caught up in this discussion is the "straight line ringer vs common audible ringing" wiring schemes.

When used as a straight line ringer (bridged ringing) or used in a small "square" key system as a common ringer, the series capacitor (generally terminated on A and K of the network) is left in the ringer circuit. In the event that the installation gets so large and complicated that the ringing plan needs to be programmed for combinations and permutations of ringers and stations, a ringing matrix is installed. It uses diode logic to create multiple layers of ringers and lines. Since diodes pass DC and not AC, the DC-blocking capacitors are by-passed in each tel set. The resulting half-wave DC is then able to operate the ringers whenever generator is sent to a ringer or group of ringers, via the diodes. The ringers, which have bias, need to polarized properly for this scheme to work, so attention to the color code is essential when installing the system.

I believe that the "pulsating DC" referred to above is what's causing the confusion with bell-tap.

Arthur what you say is true , but I have been in the interconnect phone industry since 1973 none of the techs I have worked along side of never used the term bell tap . That is the reason I stated it must be a regional term or a bell system term or my too many beers for to many years . LOL.

Bell tap was seen with rotary phones. A bad capacitor would cause the bell to "tap" when the phone was dialed..I never saw an AE phone with only a 10volt buzzer. All the ones i worked with had 100volt ringers.

Sam

Bell Tap is what I have to do (sometimes, if I want to connect directly to PBX bridged ringer, not to the KSU generator) to make the US telephones ring on European lines. US has higher ringing voltage ~100-105V. European standard is 75V. Frequency is also different, but it’s a minor shift: 25Hz vs 20Hz, or Cycles as one says in the US.
Normal US ringer will only vibrate on EU line, not touching the bells.
To fix this, I have set the bias spring to lower catch (or release it). Bell has less mechanical resistance in this case and can ring on lower voltage (though in reality I also have to play with the coil position on the core: fine-tuning the optimal magnetic transmission with matches).
As far as I understand or heard, this option was included into all Bell System ringers’ designs to allow using them on remote rural lines, where ringing voltage can go down significantly due to the length of the loop.
Hovewer, this setting makes the ringer “Bell Taping” on rotary dial phones (I have one Stromberg-Carlson 554 which does exactly so), when one dials out.

My new phones have just flew in to Frankfurt airport.

We used to adjust the the bias spring first and if that didn't work we could reverse the two leads on the ringer. And as a last resort we would add a 1A thermistor in
series with the ringer.

Sam the AE 186 sets out here only had a 10v buzzer no ringer. The Logic sets had ringers but we never used the ringer.

Didn’t try to reverse the coil sides, but probably it’s a decent option: some phones start to ring with reduced spring tension, some - not. But this is an old issue for now anyway: I feed all phones from ringing generator now, so the issue doesn’t exist.

"Sam the AE 186 sets out here only had a 10v buzzer no ringer. The Logic sets had ringers but we never used the ringer."

Was this for religious reasons?





Really? All Line ringing AND Intercom signaling was with buzzers?

Sam

Some highlights of newcomers to the collection:

WE 565 Pink - this one will require a lot of color restoration and fading removal on the front side - and Nothern Telecom/ITT light gray don’t know their numbering - analog of 564.



Some of the colored sets from 2565 series:



Chocolate Brown ITT 2564 with matching color brown Precision Components 4A Speakerphone. Base of the set will be changed to WE 2565 to accommodate speakerphone service. Unfortunately PC-108A loudspeaker was cracked on the way to me. Will have to figure out how to restore the missing corner piece of plastic. I’m crying, still... it was such a luck to find both parts in different places almost at the same time and in non-cracked condition. But long way did its work.



Finally have an ivory 4A from WE and a 2565 body with original design (transparent) faceplate. Very nice looking combination.



I call this phone “Richard Nixon”, hope you know why. Though Richard Nixon never had 4A speakerphone in his Oval Office.



Cherry Red WE 2851. This was difficult to find, though it is WE factory paintwork. But all in all well done. I saw recently a similar model in Aqua Blue, but that was sold for crazy money.



And finally now I can open a branch office of Bell System - the logo is ready

all I can say is wow!!