104A Induction Coils

[Babybearjs]

Today, I got a W.E. 309A telephone, my very first. though at first glance, it could be a 307A. the main difference that makes me think that its a 309 is there is NO 330 ohm resistor across the "A" and "C" terminals and the "A" terminal is soldiered to the coil winding. the funny thing is, the coil model number is still a 104A. one would think it would be a 104B or something like that.... there was no vacuum tube inside, the ringer was disconnected and the terminals taped.... so those got put back on the right terminals. I toned out the phone and got a signal, still need to replace the feet and line cord.... But my main reason for writing this thread is to ask, was there 2 versions of the 104A induction coil? one, with a resistor showing, and another with the resistor built-in to the coil. this is the first time I've ever seen this on this coil and just wanted to ask to see if anyone knows.....   John

[unbeldi]

The 307 and the 309 are both local-battery talking and common-battery signaling telephone sets, and have the same audio circuitry.  The difference between these is that the 307 is for non-polarized ringing while the 309 has the tube for selective polarized ringing on party lines.

So, if yours doesn't have the gas tube, it has essentially been converted to a 307.

Does the phone show any signs of being handled unprofessionally (non-WECo style)?
There is no reason to ever remove the resistor, but I have encountered many collectors' ideas of doing so. In all such cases, they just don't understand how it's wired and what it is for.

So, no, I have never seen official model of the 104 coil that does not have a C-A resistance.  However, I should ask you about the manufacturing year of the phone.  What is the date stamped on the coil? The early 104A coils did not have a resistor, but used a non-inductive winding instead.  This is probably the case in yours.

[unbeldi]

Would you be able to share a picture of the induction coil?

If this coil is an original 104A with a non-inductive winding, we should record its date, because these are hard to find.

http://www.classicrotaryphones.com/forum/index.php?topic=11422.msg129655#msg129655

[Babybearjs]

Thank you for the posts. I'll double check the phone and post pictures. there is no date on the coil itself, and I'll try to find a date on the phone. it was really dirty and had to be completely disassembled and cleaned.... cobwebs and all.... but there are still dates in the unit....

[Babybearjs]

.... PLEASE SEE THE POST: Variations on a theme. this is the continuation of this thread....