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Trying to Connect WE N317 & Kellogg Wall Phones

Started by bidnadir, May 21, 2019, 06:28:38 PM

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bidnadir

Hi everyone I am new to the forum here.   I have two old wall phones, a Western Electric N317-X SPEC and a Kellogg which I am trying to connect together.    I am currently using jumper cables to connect the phones using L1 to L1 and L2 to L2.   In each phone I have three AA batteries connected putting out 4.5 volts.    When I crank the Western Electric both phones ring, and when I crank the Kellogg just the Western Electric rings.    This is as it should be as I have read prior posts on this forum and the Kellogg doesn't ring locally but the WE does.   Therefore, the ringers are working perfectly.   

Where I am having trouble, and where I need your help, is with the voice connection.    When the receivers of both phones are taken off hook, I get full duplex connectivity from the Western Electric, but only half duplex (transmit only) from the Kellogg.   When putting the receiver of the WE to my ear, I can hear clearly when tapping on the Kellogg receiver, however, when listening from the Kellogg I hear nothing when tapping on the Western Electric receiver.

I have done a fair bit of checking, and have eliminated the transmitter and the receivers as being the issue by swapping them between the units.  I have also double checked battery power and the various hook switches and other switches to ensure contacts are opening and closing correctly.   

The Western Electric has some key differences relative to the Kellogg in that the WE has a condenser and also has a switch on the side which I believe was used to call an Operator.    The Kellogg is more basic and doesn't have these features.   

I suspect the issue may be with the induction coil in the Western Electric which may be the cause for it not transmitting to the Kellogg, but I am not sure if that's correct or how to test that theory.    I am also wondering if the differences in the Western Electric may require it to be wired differently.

I'd greatly appreciate any thoughts and assistance you can provide.   Thanks in advance.

RB

Hi and welcome!
Nice phones
I suspect you have a connection problem.
Chk the receiver connections in the Kellogg.
Take a single batt, and clip leads and touch the batt across  the rec wires briefly.
You shud hear a scratching in the rec.
If thats good, jump the hook switch contacts and see if that restores sound in the kellogg.
Do you have the schematics for each phone?
Those are simple phones, it shud not take long to get them playing nice together.

bidnadir

Hi, thanks very much for the help! 

The battery test across the receiver wire terminals of the Kellogg worked and provided a nice loud spark sound in the Kellogg receiver.

I jumped (connected) all three of the receiver hook terminals together, but it makes no difference and still not getting sound.    Knowing where you were going with this I also cleaned the receiver leaf switches, but still no luck.

I don't have the exact schematics for the phones.

Rookie question here:  Does the induction coil have anything to do with the voice connection?   Just wondering if the coil in either of the phones could be the problem.

CW

Jack Ryan

Is the circled wire connected?

Try bridging the capacitor on the WE telephone.

The induction coil isolates the battery circuit from the line and matches the transmitter and receiver to the line.

Regards
Jack

bidnadir

Hi,

Yes, the wire you've indicated is connected to a channel in the back of the Western Electric phone although I am not sure where it runs from there.   The other end connects to what I believe was a switch to summon the Operator on the left hand side of the box as you can see in the pictures below.   

Depressing the 'Operator' switch makes no difference.   I have also tried jumping the 'Operator' switch and again it makes no difference.   

I have noticed that switch turns off the bells when ringing outbound from the set, but seems to make no difference to the voice issue.


dsk

Hi, and welcome to the forum!
I'm not sure, but I suspect that the Kellogg receiver might have to be repaired.  If you have another receiver just to test the system...

The receiver diaphragm may need to get the correct distance to the magnet.

Approx 1 mm use to be OK for most receivers.


dsk


PS a mobil-phone ear  plug should be enough to test the signal as a replacement of the receiver
DS

bidnadir

Hi,

I had another receiver, so tested it by using it first on the Western Electric and confirmed it worked, and then used it to swap with the Kellogg, but this made no difference.   I also swapped all three of the receivers around as I had a hair brained idea that they might be of different impedance or some such, but regardless of receiver combination, I always am only getting sound out of the Western Electric.

One weird thing I discovered though all of this is that when holding the WE receiver to my ear that I not only get sound from the Kellogg transmitter, but also get sound from the WE transmitter as well.   Not as loud from the WE to WE as from the Kellogg to WE receiver, but still relatively loud.       Not sure if this is normal behaviour or not...

CW

Jack Ryan

I think you said the phones ring each other OK. If that is the case, lift the receiver of the Kellogg and crank the WE - what changes with the Kellogg receiver lifted?

Quote from: bidnadir on May 23, 2019, 11:13:26 PM
One weird thing I discovered though all of this is that when holding the WE receiver to my ear that I not only get sound from the Kellogg transmitter, but also get sound from the WE transmitter as well.   Not as loud from the WE to WE as from the Kellogg to WE receiver, but still relatively loud.       Not sure if this is normal behaviour or not...

That is normal - you always hear yourself, it is called sidetone. In fact if the Kellogg has no sidetone it would indicate (with the other symptoms) that there is a fault in the Kellogg receiver circuit. The WE does not need to be connected for this test.

If WE cranking does not get hard when the Kellogg receiver is lifted and the Kellogg has no sidetone - there is a receiver circuit fault in the Kellogg.

Jack

Jack Ryan

By the way, 3 volts is the normal supply for these telephones.

Jack

dsk

Not easy to understand, but if you have an ohm-meter, you may look at the wires I did draw on your phone.
Starting on the left terminal, it should be almost no resistance to the right receiver terminal, a resistance further to the  left receiver terminal should be equal to the receiver resistance 30-120 ohms.  Then from there to the lower left induction coil terminal close to 0 ohms, and further 15-50 ohms to the right side of the coil. The right side terminals should have a common wire to the upper hook-sw terminal. Close to 0 ohms.  Then all the 3 hook-sw terminals should have close to 0 ohms between each other (in off hook pos.) From the lower hook-sw terminal you should have close to 0 oms to the Right line terminal.

The green drawing is the known  working transmitter circuit.


dsk


PS based on this page: https://bre.is/Se6vjf-kM DS

bidnadir

Hi Jack, when I crank the WE and then lift the Kellogg receiver, the cranking gets markedly harder.   

I am now going to work through the tests that DSK has recommended and will report back.

Really appreciate the help with this guys !

Charles

HowardPgh

The condenser in the Western Electric phone is usually in series with the receiver. This is to allow other phones on the line to ring if the receiver is accidently left off hook. One way to test this is to bridge the condenser with a jumper, take the receiver off hook and try to crank the phone, the generator will turn hard, put receiver back and the crank will turn easier and ring the bells.
The button switches one of the magneto leads from a metal line (L1 or L2) to ground so you can ring the operator without ringing all the other phones on the party line.
Howard

bidnadir

Hi DSK,

I have completed all of the tests and to make the results of each test clear, I have included the test results within the attached photos.   Below are your instructions with the results I found:

-Starting on the left terminal, it should be almost no resistance to the right receiver terminal:  0 ohms
-A resistance further to the  left receiver terminal should be equal to the receiver resistance 30-120 ohms:  80 ohms
-Then from there (the left receiver terminal) to the lower left induction coil terminal close to 0 ohms:  0 ohms confirmed
-And further 15-50 ohms to the right side of the coil:  28 ohms
-The right side terminals should have a common wire to the upper hook-sw terminal. Close to 0 ohms:  0 ohms confirmed
-Then all the 3 hook-sw terminals should have close to 0 ohms between each other (in off hook pos.):  0 ohms off hook / 600 ohms on hook
-From the lower hook-sw terminal you should have close to 0 oms to the Right line terminal:  0 ohms

Again, really appreciate your help.

bidnadir

Hi Howard,

Regarding the condenser test for the Western Electric, I did exactly as you suggested and used a jumper across the condenser leads.   
-With the receiver on hook, the generator spins freely and the bells ring.
-With the  receiver off hook , the generator turns hard and the bells ring, but not as well
-When I press the Operator button, both off hook and on hook, the generator spins freely and the bells do not ring.

Appreciate the help.

Charles

bidnadir

Also, just as an FYI, I have changed the battery voltage in both phones to 3 volts DC using two AA batteries in series.   Hasn't made any difference to the operation of the phones, but at least doing this eliminates it from the equation of possibilities.

Charles