"The phone is a remarkably complex, simple device, and very rarely ever needs repairs, once you fix them." - Dan/Panther
Started by bobv, December 03, 2018, 04:58:29 PM
Quote from: dsk on December 04, 2018, 05:02:33 PMThis is a local battery set, never seen any equal, but I it was mine, I had tried to put a battery of approx 3V between the terminals 9-10Line between 2 -3 and a ringer capacitor between 3 - 1 The capacitor should be non polarized and rated at least 200V. approx 1 microFarad.When you go off-hook, and press the call button you should get dial tone. Dialing will result in loud clicks in the receiver!Try it out.dsk
Quote from: FABphones on December 04, 2018, 05:07:51 PMInfo from link above.
Quote from: dsk on December 05, 2018, 02:07:29 AMAs mentioned, this is a LB circuit with a non standard dial attachment.Wiring line as described makes the Capacitor working as a ringer capacitor, and lets the voice signal pass. It might have been better to solder it in to the Ringer, but this makes it working without changing the phone. Adding a Battery and you may use it as an LB phone. If any other phone are used on the line you may just lift off the receiver and join without using any line power. When you press the call button a DC path is established (green dotted line) using 1/2 of the ringer as a holding coil. This Holding coil may have to high resistance for some lines, but it seems to work here. The rotary might work, but again the high resistance holding coil might be a problem. Moving the wire from the dial according to the red markings may solve it. The voice signal follows the orange dotted lines just as if it was an LB line. The light blue dotted lines shows the battery circuit where the transmitter "generates" the sound signal.Since the dial only uses the pulse contacts, loud clicking in the receiver will be heard during dialing.dsk