Western Electric 307

[Babybearjs]

one thing I alway do when I get a phone is to completely disassemble it and wash the case with warm soap and water, the handset too (don't forget to take out the T and R modules!) amazing how a bit of TLC can save a phone! with my 307's though... I had a rough time reassembling them as far as the wiring went, I had to pull up the 307 Schematic to verify the connections! but handwashing the shell, handset, and other non-electrical parts took care of any mold and other dirt that was on the inside of the phones....  John

[trainman]

From information in Ralph Meyers book, the 307 could be used on straight local battery lines or at the end of a really long common battery run.

Since the batteries are in the talk circuit, they do make a phone that was powerful enough to get through on a long common battery run with major voltage drop

Also, the low current produced on a long common battery run  would still be able to dial the CO if the phone was dial, but there wouldn't be enough talking power . Hence, the local battery talking circuit.

So, by adding battery, the phone can be used on common battery with no wire mods.

WDS, if you don't want the phone, I'm interested in it.

[wds]

My original posting was a while ago, and I didn't understand or appreciate what a 307 was, so i sold it.  I kick myself every time I think about that phone - wish I still had it.  Someday I'll find another one, buy it and keep it this time.  The bad part was, I only paid $10 for it, and the cloth cords were like new.  I'm a little smarter now, so i won't make that mistake again.

[Babybearjs]

it took me awhile to find this old thread.  I won another 307 on ebay and wound up paying $30.00 for it. while cleaning up the phone it dawned on me that I did not need to make any wiring modifications except for the black receiver wire. I had stated in earlier about using the jumper that is installed on the "C" terminal on the inductor. today I was testing the phone and got a dial tone with no problem with the phone being wired as per the BSP. the only problem being that the transmitter did not work. I moved the black wire from BK to L1 and it started to work like intended. the receiver is kind of low, but you can hear the other party OK. I added a dial to the unit I have and it dials out just fine. if you keep the 5 conductor cord, you can use the blue, black, or Yellow wire for a bell cut-off lead and add a SPST switch to the unit to silence the bell. its recommended that you use a KS-19504-L1 switch for this so as not to ruin the chassis of the phone. I mounted several of these on a few of my phones with double sided mounting squares on the side of the phones to shut off the ringers in certain rooms. The bells in the 300 series phones are quite loud and 1 phone can be heard throughout the house. 

[unbeldi]

it took me awhile to find this old thread.  I won another 307 on ebay and wound up paying $30.00 for it. while cleaning up the phone it dawned on me that I did not need to make any wiring modifications except for the black receiver wire. I had stated in earlier about using the jumper that is installed on the "C" terminal on the inductor. today I was testing the phone and got a dial tone with no problem with the phone being wired as per the BSP. the only problem being that the transmitter did not work. I moved the black wire from BK to L1 and it started to work like intended. the receiver is kind of low, but you can hear the other party OK.
....

No it is not working as intended.
It is intended to use a battery for talk energy.

By connecting BK to L1 the transmitter is connected directly across the line without any use of the primary winding of the induction coil, and therefor without use of the induction coil for transmission. A transmitter is essentially a varying resistor and thus it is waisting energy in your circuit that would normally be converted by the receiver into sound.  This is the reason for the reduced volume.

You have reduced the instrument to a primitive circuit not much different than the first telephones of the 19th century.  It is easy to push audio through a miswired telephone and hear dial tone, even perhaps transmit something, but this doesn't mean it is working properly.

[Phonesrfun]

today I was testing the phone and got a dial tone with no problem [with the phone being wired as per the BSP]. the only problem being that the transmitter did not work.

Did you try connecting a battery across the black and the blue line cord wires?  That would have been proper wiring since the 307 is a local battery set.

[Babybearjs]

thank you for the info. No, I have not added a battery to it yet.  I'll have to try 2 AA batteries and see how that works. normally I convert the phone to CB service, but it seems every time I work on this series phone, the outcome is different. I'll have to compare my work with other sets. ultimately I could change out the inductor to a 101a and wire it like a 304 with the extra switch hook pair as the A-Lead for the 1A1 system.

[Phonesrfun]

Just an opinion, but it seems that an original 307 in its original configuration would be preferable from a collector's standpoint than just another 302/304. 

[Babybearjs]

the whole idea here is to make is compatible with a CB system. and I found the problem.... heres what I did:

    1. move the Blue Line cord wire from BL to E on the small terminal board.
    2. Take the Jumper on C and connect it from C to BL
    3. Omit the RED wire from the dial to the R terminal (I moved the wire to the BK Term. on the main terminal strip)
    4. Move the Black Receiver wire from BK on the terminal strip to BK on the dial.

This converts the phone from Local Battery to Common Battery so you can use the phone on any land line.

  If you want to use the phone on a Local Battery setup, just reverse the above procedure.

it was the red wire that was causing the problem. it was shorting out the transmitter. I'm so used to working on the 302's that when I when I added the dial, I was so used to seeing 2 black wires in the BK term of the dial that it made sense to see the Red wire as black on the phone but I forgot that the 307 has 2 caps for the circuit and on the 302 there is only one.

I know as a collector you want to keep the phone in original condition, but when you want to use the phone..... sometimes you have to make modifications to get the darn thing to work on todays systems. (oh yeh.... and pay attention the way you dress the dial wires.... sometimes they interfere with the ringer)

[unbeldi]

One of the intended uses of the 307 was installation on common-battery lines.  The other was for use on magneto lines for which it was combined with a 299F magneto generator box.
When operated on common battery lines, it used the central office battery only for signaling, because the set was only used on lines long enough to provide too little power for transmitter operation while supervision and dialing were still possible.
Because of the use of a 104 induction coil in this, there is no wiring scheme that makes it proper to use the set without a local battery without significant altering of the transmission characteristic of the set and destroying the proper anti-sidetone and line balance.

So, even on 'modern lines' it should be used with a local battery (or power supply) between BL and BK. It can be used just fine that way.  In analogy... it is very hard to improve on Mozart.

[Babybearjs]

that's true, but for some reason this conversions works great. I have called my neighbor on the phone and she can hear me fine as well as I can hear her. the phone rings and I have taken the white and yellow wires and used them on some sets for ringer cut-off leads. by putting a SPST switch across these leads, you can control the bell. after doing a inventory, I found I have 6 desk sets and 1 wall unit.  its funny, when looking at the photos when bidding I always look to see if there are the 2 screws on the bottom in the front were the small induction coil is mounted. that way I can tell whether or not it is a 307. maybe some day I'll have a cabin out in the woods with no utilities and be able to build my own local battery system. I one thing that's important to remember is if the US ever were to have a national emergency and all cell service were lost, I'd have enough phones to help reconnect the neighborhood..... if it ever came to that.

[trainman]

The local battery talk circuit puts more power on the line than common battery ever will. One reason these were used on long, rual line. In essence, these were modern replacements for old, outdated wood magneto phones. A D cell will last a long time. Quit reinventing the wheel.  It works just fine with the battery. They would have been used this way in service.

[Babybearjs]

not so much reinventing the wheel.....just making more versatile. so.... we have a phone that works on a battery.....whether local or common... it works. now, take the common battery away....does the phone still work???

[trainman]

The 307 dont need to be altered to work. Just add a talking battery. Done. They were designed with the old local battery talking circuit because that circuit puts more power on the line than common battery. So they were used in areas with very long loops. The rest of the phone still responds to incoming calls, and will dial.

Ive used them as is on regular phone lines.

Ive also wired them together like a party line and used them as a in house intercom system. Hang a magneto on them for ringing power. Very fun.

[markosjal]

Just FYI./.

I did as indicated by Babybearjs and it worked just fine!

So, then I made this diagram for modding the 307 (and 357?) for common battery.