UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Kellogg wall phones

dagskarlsen · 17th Feb 2018, 8:48 am

OK Transmitters do usually not die quickly, so it may be the cord, or the springs.
A way to test the transmitter element is to put up the transmitter, a working receiver and a battery of 3-9 V in series. (With voltages of more than 4.5 V be careful to not test more than 30 seconds at the time to reduce the risk of getting a current over 50 milli-amps, that may fry the transmitter!)

To test the wire you could start with removing the transmitter, and measure voltage over the springs in handset, it should be equal to the battery voltage. shorting and removing the short should be loud clicks in the receiver.

17th Feb 2018, 8:48 am	#39
dagskarlsen Heptode Join Date: Jan 2008 Location: Hakadal, Norway Posts: 643	Re: Kellogg wall phones - need help OK Transmitters do usually not die quickly, so it may be the cord, or the springs. A way to test the transmitter element is to put up the transmitter, a working receiver and a battery of 3-9 V in series. (With voltages of more than 4.5 V be careful to not test more than 30 seconds at the time to reduce the risk of getting a current over 50 milli-amps, that may fry the transmitter!) To test the wire you could start with removing the transmitter, and measure voltage over the springs in handset, it should be equal to the battery voltage. shorting and removing the short should be loud clicks in the receiver.