Loud click in receiver when dial is turned on North Galion

[mentalstampede]

Hello all. I just got a set of cords and am working on getting my new Galion in service, and I'm wondering if I might have a wire crossed somewhere.

The phone has a North dial installed, and works perfectly except whenever the dial is moved from the stop a very loud click is audible in the receiver.  Is this a normal issue when using a North dial, or have I got something mixed up? Other than the click, the phone dials out normally.

[Scotophor]

My guess is that the receiver is being subjected to DC from the phone line. If that's the case, the voice condenser may have failed (short-circuited) or be missing, or perhaps the phone is miswired so as to bypass it.

[mentalstampede]

Well, I just double checked my connections, and the phone is wired exactly as shown in the diagram. I can also hear the click if I connect and disconnect the line cord when the phone is off hook. So should my next step be to check the capacitance of the voice capacitor?

[Scotophor]

If you have a capacitance meter, that should do it.

A simpler method might be to disconnect one end or the other of the condenser (black blue wire from coil terminal C or blue black wire from terminal strip #4) and temporarily connect a known good condenser to those two points, if you happen to have one handy. Then test the phone to tell whether the pops have been eliminated.

EDIT: colors

EDIT #2: Upon further study of your photo, it looks like the condenser itself has screw terminals, so that might be the simplest place to disconnect the existing condenser and attach a temporary replacement for testing. I find it odd though, that the condenser seems to have the matched terminals for each section on opposite ends. However, I'm not familiar with North phones and this may be normal. Crossing up the connections on the multi-section condenser should not cause the symptom you described anyway. Is there any marking on the condenser ends that confirms which color wire should be attached to each screw?

[poplar1]

When pushing the hookswitch plunger slowly, you should not hear a loud click. Can you verify this? Also, you should not have dial tone if you remove the transmitter. While the transmitter is out, you should be able to "monitor" the line--if another phone goes off hook you can hear dial tone in the North receiver.  These are two tests for the secondary circuit, which includes the capacitor.

It's normal that you would hear a loud click when disconnecting the phone at the wall while the receiver is off the hook. That's why there are two sets of hookswitch contacts--so that you don't hear a loud click, because the receiver opens before the phone is disconnected.

The North -H6 circuit was apparently adapted from the WE 302 circuit.  But while connecting the red dial wire to L1 is fine with a WE dial, not so with an AE or North dial. In short, the diagram is simply wrong.

I don't have one close by to verify, but I seem to recall that on a North -H6 with an AE or North dial, you can move the red dial wire from L1 to R. This will still short out the receiver when dialing so that you don't hear the clicks of the dial pulses. Perhaps it will also help suppress the click you are hearing when starting to dial and when the dial returns.

In any case, with any older phone, you may decide to add a varistor  parallel to the receiver to suppress voltage spikes (loud clicks) when going off hook.  G-type handsets (U-1 or U-3 receivers) always have varistors, but the older handsets did not.  WE usually added separate varistors when headsets were used and also in pay phones with F-type handsets.

[mentalstampede]

@Scotophor:  The condenser wires are soldered in; there are no screw terminals there.

@Dave: My phone behaves as you described. Moving the dial shunt wire to the R terminal on the coil fixed my issue! I was certainly hoping there would be a simple fix, but it never occurred to me that the diagram might be incorrect! I've got another older parts North in storage, and I'm going to pull it out and compare the two diagrams just out of curiosity now.

Thanks for the help, guys.

[poplar1]

The earliest North -H6 sets did have a different wiring diagram, but that one is even worse. With it, there is always a loud pop when hanging up.

[mentalstampede]

Yeah, it looks to have the dial shunt run to the same terminals. Here it is if anyone is interested. The above diagram is from a 1955 dated set, the one in this post is from a 1944 dated set.

[BDM]

Hmmm, never knew that myself on my North sets. Good catch Dave

[poplar1]

There is another diagram with slightly different wiring for WE dials. It shows a North 4H6 with the receiver (white handset) connecting directly to GN. This is shown in BSP Section C32.505, Issue 1, 12-3-45. The receiver is not opened by the hookswitch.

http://telephonecollectors.info/index.php/document-repository/doc_details/1964-north-4h6-desk-set-with-we-dial-4h6sld-tl


This was changed in the addendum issued 5-31-46, with the set recoded 5H6. Among other changes, the white handset conductor was moved to 2 (for manual sets) or W on a WE dial. So perhaps the problem I was recalling--loud click when hanging up--was only on the sets factory wired for WE dials. In any case, both of your diagrams, the hookswitch does open the receiver before disconnecting the phone.

http://telephonecollectors.info/index.php/document-repository/doc_details/4587-c32-505-add-i1-may46-tel-sets-north-electric-5h6

[TelePlay]

For easy comparison, here are the two schematics from above in one post.

[mentalstampede]

Just for completeness sake, here's some photos of details on both phones.

There's quite a few little differences in addition to the diagram. Does anyone know anything about the induction coil in the 1955 phone? the '44 has a WE 101A, but the one in the '55 is unmarked and of slightly different configuration.