So, how many W.E. 307's are there???

[Andre91]

...Or the exchange was strictly a magneto-signaling exchange, but why would they install a 307 in this situation?

I would think they would have just installed a 250 handset mounting in that case?

[trainman]

I have 6, all with magnetos for the ringer. The best thing to do with these is to leave as is, connect like a local battery phone, and use like an intercom. The red and green are the line wires and the black and blue wires are the battery circuit. Connect 3 volts here. One can see how to use a regular connecting here. Just connect a d cell holder to two terminals on the block.  To use on CB service, no changes are needed. Just add a battery. It will last a long time.

[trainman]

The 307 can be used with a magneto for signaling as in local battery magneto service, or without as in CB signalling service. Since the phone has a network, only a 299F magneto was needed. All connections, magneto, line, and battery, were made at the connecting block. I forget the number of a five terminal block.

[trainman]

The 307's were used in both LB and CB services. They were used at the ends of very long CB loops. The DC power was still good enough to operate the Dial for switching, but the loop was too long for a regular common battery phone to put enough talk current on the line. The Local battery circuit puts a strong signal on the line. So, the combined the two curcuits into this phone.

Trust me, it works if you take the 307 as is, and just add a 3 volt battery in the talk circuit. The phone draws minimal current, so the battery will last.

Or just wire them together as an stand alone magneto in house phone system. I;ve done that also.

[HarrySmith]

I have at least 2. One from Bryant Pond, last manual service in the US. There may be more in my "to do" piles

[zaphod01]

My 307 is marked 307A/C. I understand the 'A'. What's up with the 'C'? (I've been through the BSP's but couldn't figure it out). It has the original five wire cord.

[unbeldi]

My 307 is marked 307A/C. I understand the 'A'. What's up with the 'C'? (I've been through the BSP's but couldn't figure it out). It has the original five wire cord.

Does it have a dial or is it actually a manual set?

[poplar1]

A:C=C:D
The same baseplate was used on the manual (A) as well as the dial (C) version of the 307, just as the baseplate of a 500 is marked C/D indicating that it can be either a 500C (manual) or a 500D (dial).

In neither case is the complete phone a "307A/C" or a "500C/D." It depends on whether it has an apparatus blank (307A, 500C) or a dial (307C, 500D).

[paul-f]

My 307 is marked 307A/C. I understand the 'A'. What's up with the 'C'? (I've been through the BSP's but couldn't figure it out). It has the original five wire cord.

Try C32.502, issue 7, page 9
  http://www.telephonecollectors.info/index.php/document-repository/doc_details/685-c32-502-i7-apr54-300-series-and-d-173487-telephone-sets-description-and-use

Once you know A/C means A or C, it shows the components of the 307A (manual) and 307C (dial) sets, and other variations.