Popping sound when dialing a Western Electric 102 B1 wired to a 534A sub-box

[Jf510]

I have two Western Electric 102 B1 telephones that I wired each one to a 534A sub-box. They both dial out fine, ring fine and have a nice dial tone. I use the same wiring diagram that I use for a few 202’s I have to 634 sub-boxes. With the 102’s when dialing and the finger wheel goes back to the stop position each time I get a real loud pop from the handset. It doesn’t do that on my 202’s so I am stumped on why it’s doing that. Is this normal or am I doing something wrong?

[unbeldi]

The circuit and wiring of a 102 type instrument is a little different than a 202, so if you used the same wiring, something is not quite right.

The 102 telephone uses a three-conductor mounting cord to the subset, while the 202, having an anti-sidetone circuit, uses a four-conductor cord.  The fourth conductor is needed to complete the anti-sidetone feature.

There should be no pops at all during dialing or at the end of it. The fact that you do get that indicates a wiring mistake. It implies that the receiver is not shorted properly during dialing by the off-normal dial switches.

What kind of dial do you have on the 102s?

[Jf510]

Thanks for responding. I didn't know the 102's used a three conductor cord. Both dials are 5H. How would I wire it from the 102 to the 534 then?

[unbeldi]

The original dial on a 102/B1 was a 2H until 1930, then a 4H, but a 5H is perfectly compatible.

Here is a circuit diagram for the 102.  It looks a little different than the wiring diagrams that everyone else (re-)produces, but with this one can actually understand how it works.

I indicated the components that are in the B1 handset mounting in the gray box, and the mounting cord wires (red, green, yellow) are indicated.

HS1 and HS2 = Hookswitches
DS1 and DS2 = off-normal dial switches
DP = dial pulsing contacts

You should match up the dial and hookswitch terminal designations with those found in your set.

I drew that diagram for grounded ringing in the traditional fashion, for modern lines simply connect the GND terminal (or the red ringer wire) to L1.

Please compare with my picture of a correctly wired subset.

PS: You're in luck... I also have a picture of a B1 wired with a 5H dial. See last picture.

[Jf510]

Thanks although I am a beginner with this wiring of telephones so your diagram is a tad complicated but I will try and figure it out. If you could explain more simple that would be appreciated like what colors go to what terminal on the 102 & 534.

[Jf510]

oh darn..I didn't bring the page down far enough to see the two pictures of the phone and box. Thanks so much.

[G-Man]

Thanks although I am a beginner with this wiring of telephones so your diagram is a tad complicated but I will try and figure it out. If you could explain more simple that would be appreciated like what colors go to what terminal on the 102 & 534.

See if this helps...

[Jf510]

I followed the wiring diagram with the 3 lead cord according to the pictures and diagram (same) as above and I am still getting that loud popping sound every time I dial a number. I am back to stumped.

[unbeldi]

I followed the wiring diagram with the 3 lead cord according to the pictures and diagram (same) as above and I am still getting that loud popping sound every time I dial a number. I am back to stumped.

Did you rewire both the desk set and the subset?

Can you take a picture of the inside with dial and connections clearly visible, like in my last picture?

[Jf510]

Hi..yes I did wire both phones with a 3 lead cord. Enclosed are the pictures of one set.

[poplar1]

Incoming line should be on L1 and L2-Y. You now have it connected to L1 and GN.

[Jf510]

I can't believe I made that stupid mistake on that phone. The other one I did was right but I am still getting that loud pop each time the finger wheel stops when dialing on both sets of phones. Is that a characteristic of the 102's?

[poplar1]

OK, I just noticed that the first photo you posted had the line cord connected properly. Do you also get a loud pop if you hang up slowly? What about if you disconnect the green mounting cord wire from GN on either end?

The wiring inside of a 102 (round or oval) and a 202 (round or oval) is the same, other than the added fourth (black) wire that goes to BK on the dial.

So you could connect one of your other working 202s (no pops when connected to a 634A) to a 534A subset by taping and storing the black lead on the subset end, or connecting it to the spare GND terminal. If the transplanted 202 now has pops, then the problem might be with the 534A subset. If not, the problem must be with the 102 wiring or dial.

EDIT: I meant to say to disconnect the green wire while the phone is off-hook and you are listening to the receiver. There should not be a pop then, or when hanging up the phone slowly.

[Jf510]

The set I took the picture of does pop loudly when hanging up. The other set not so loud. When removing and connecting the green mounting cord on both sets of 102's there is just a slight noise.

[Jf510]

I finally exchanged another sub-base with the 102 that pops loud when dialing stops and when the receiver is pushed up and down and the loud pop is still there. Could it be the dial? I read that the contacts need to open and close at proper times but outside of oiling a dial that's all I know about it. I don't know what else to check. I know the wiring is now correct.