Western Electric H7

[Babybearjs]

Thanks....

[unbeldi]

There were several other options for tuning also, depending on the transmission zone where the station was installed. For example, the extra condenser could be wired in various combinations with the resistor to achieve the proper balance. This also included adding additional resistors.

There is a BSP for that:  C63.289 Issue 6 1948-05-25

[unbeldi]

@Babybearjs:   I recall that you are running a 1A or 1A1 key system.  If so, there is a perfectly proper way to run your 307 sets using the DC supply in the KTS as a shared battery.  This requires a No. 2 or 12 KTU (battery feed) and a No. 27 KTU (has only a condenser), but similar devices could be made from capacitors, resistors, and a No. 46 induction coil.  See ADDENDUM C63.289 Issue 1, August 1954.

[Doug Rose]

I have several of these... once converted, they work great!

They work great just the way they were intended, designed, and made. And that is the only way they operate correctly.

Many things, telephones, and others can be made to work in various ways, but these cannot be operated with the same efficiency in another way. All components are tuned to each other for the intended purpose.
If you want to operate a 302, then buy a 302, it doesn't look or feel any different. They are plentiful and cheap.

Owning or operating a 307 has no other purpose today than demonstrating a piece of history. As such it makes no sense to operate it any other way.

Karl...I agree 100%. I have phones that I elected NOT to make working to keep the original dated parts in them. Sometimes is is best not to mess with historical items.

See the Manual 37 302 that Mark found that is jumping through the ceiling. Historical correct is sometimes a lot more important than working on today's systems....Doug

[Babybearjs]

No, the 307's aren't being used through my key system. but they are used on my landline when needed.... occasionally I'll use one to test the phone line from the demarcation point when I'm having problems... they work fine on the line and dial out with no problem. all I do to get them working is to change the line cord from a 5 lead to a 2 lead, take the jumper on "C" and jump it from C to BL and then put a jumper on BK and attach RBK the rest stays as wired. this is how I convert this phone to CB service.

[dsk]

I would guess this phone would work better than a 302 on my old common feed pax, if I had a line considerably longer than the others. It will automatically be less power to the most remote phone, and here a better line matching, and local battery talking will be great.

The next question: what is the difference between 307's with different letters?

dsk

[unbeldi]

I would guess this phone would work better than a 302 on my old common feed pax, if I had a line considerably longer than the others. It will automatically be less power to the most remote phone, and here a better line matching, and local battery talking will be great.

The next question: what is the difference between 307's with different letters?

dsk

The letters that I didn't already explain are for the typical dial face substitutions, B/F = 5HA, C/G = 5HB, and D/H = 5HE.

[Babybearjs]

dial face?? they used different dial faces? I assume it was numeric, alpha-numeric, and partyline....

[unbeldi]

dial face?? they used different dial faces? I assume it was numeric, alpha-numeric, and partyline....

You posted the chart of model suffices here yesterday, so there shouldn't be any surprise.

Your chart, btw, came from a later BSP and doesn't mark the 307D and 307H anymore, because they had been discontinued. IIRC, there was a BSP issued, perhaps a local telco BSP, which stated that orders for these could only be fulfilled from any local left-over stock.

[wfs1933]

Thanks for all the detailed info unbeldi !  (most going over my head i confess ) i have since bought another but this one has a 104 coil for some reason and the F1 handset has an G receiver in it  I've never seen that.