Author Topic: Barely able to hear on one phone  (Read 964 times)

Offline Paul Boomer

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Barely able to hear on one phone
« on: November 02, 2017, 12:13:55 AM »
 Newbie, first post so be gentle please.

 I have 2 wooden wall magneto phones that I use as an intercom from the house to the barn. One is a Kellogg and the other is a B&R Electric. They have worked well for years with a few battery replacements but now the B&R can barely hear what is spoken into the Kellogg, but the Kellogg has good sound from the B&R. Both have 3+ volts battery voltage and I have cleaned the terminals and contacts that I can find. Is there another place to check?    Thanks  Paul

Offline Dan F

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Re: Barely able to hear on one phone
« Reply #1 on: November 02, 2017, 02:34:24 AM »
Sounds like it could be packed carbon granules in the Kellogg. You might try and remove the transmitter and give it a good whack to loosen the granules. Have seen it many times before.


Offline dsk

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Re: Barely able to hear on one phone
« Reply #2 on: November 02, 2017, 04:06:01 AM »
Newbie, first post so be gentle please.

 I have 2 wooden wall magneto phones that I use as an intercom from the house to the barn. One is a Kellogg and the other is a B&R Electric. They have worked well for years with a few battery replacements but now the B&R can barely hear what is spoken into the Kellogg, but the Kellogg has good sound from the B&R. Both have 3+ volts battery voltage and I have cleaned the terminals and contacts that I can find. Is there another place to check?    Thanks  Paul

Hi, and welcome!
If you hear yourselves loud and clear in the Kellogg the Kellogg transmitter works OK, if not, try to do as Dan says. If not we have to look at the other phone. Even there the question is do you hear yourselves loud and clear or not.

dsk

Offline Duffy

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Re: Barely able to hear on one phone
« Reply #3 on: November 02, 2017, 04:50:31 AM »
Welcome to CRPF.

Offline Ktownphoneco

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Re: Barely able to hear on one phone
« Reply #4 on: November 02, 2017, 11:01:02 AM »
Welcome to the forum Paul !    I'll hazard a guess and say that the Kellogg set is in the barn.    If that is in fact the case, then Dan's suggestion is probably fairly accurate.     I've included 2 pictures here so you can better understand the problem.     The pictures show a transmitter button from either a Western or a Northern telephone set similar to what is in the 2 sets you have.     The shape and size may differ slightly, but they they operate the same way.    The brass button assembly contains carbon granules which I've pointed out in one of the pictures.    Barns are generally damp places, especially if you have a dairy operation.     The transmitter buttons are not totally moisture proof, and over time, moisture will seep into the button causing the carbon granules to clump together.  Every time that happens, the less sensitive the transmitter becomes, which obviously reduces the amount of sound it picks up and transmits down the wires to the other telephone in the house.     What needs to be done, is to try and remove as much moisture from the transmitter button as possible, and break up the clumps.    Doing that is little more involved than merely stating the fact.   It's difficult to do this with the transmitter button still in place.     I would suggest this :   There should be 4 small machine screws holding the transmitter face plate in position.     carefully remove the screws and place them in a safe spot.    They're probably something around a No. 2 round head machine screw, and they're hard to find if dropped, especially on a barn floor.   Remove the transmitter face plate, and disconnect the one or two wires connected to the transmitter, and take the transmitter in the house and place it near a warm area like the kitchen and let it sit for a few days and every so often, rap the edge of the transmitter face plate every so often, (the more the better) with a plastic or hard rubber handled screw driver.    That tends to break up any carbon clumping.     After a few days, re-install the transmitter back into the telephone in the barn and you should hear an improvement.    Ideally, I'd suggest switching the two sets between the barn and the house every couple of couple of years, or whenever you experience poor transmitter quality in one of the sets.
I thought the pictures ( click once or twice to enlarge )and a written explanation of what's going on, might help you with the problem.      Good luck !

Jeff Lamb
 

Offline Paul Boomer

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Re: Barely able to hear on one phone
« Reply #5 on: November 03, 2017, 11:37:27 PM »
 Hi everybody,

 I'll give the Kellogg a looking into and thump it some. I don't think moisture is a problem here in Tucson but it still is something I'll look at. I have a spare Kellogg that I can try switching out if all else fails.

 Thanks for the inputs, seems like it is a common problem since everybody is in agreement.   Paul

Offline 19and41

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Re: Barely able to hear on one phone
« Reply #6 on: November 04, 2017, 09:37:26 AM »
Whatever the problem is they will get it sorted out for you.   Welcome!
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline Paul Boomer

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Re: Barely able to hear on one phone
« Reply #7 on: November 05, 2017, 02:43:02 PM »
Jeff,

 Here are 3 pictures of the transmitter I have and it looks completely different that the one you showed. Am I not looking at the transmitter or is this a different style that needs a different cure than drying and tapping?

Paul

======================

EDIT:  up to 6 images can be added to a topic or reply - see last image below on how to do that
« Last Edit: November 06, 2017, 01:49:14 AM by TelePlay »

Offline Ktownphoneco

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Re: Barely able to hear on one phone
« Reply #8 on: November 05, 2017, 04:07:02 PM »
Paul   ...   The picture of the carbon button I posted, is a Western Electric type carbon button.      The physical design is somewhat different to that used by Kellogg, but they operate on the exact same principle.    Now that I can see you transmitter assembly, you may, and probably do have another issue at play here.    I've taken one of your photos and added component names to assist in my explanation.    First, go ahead and shake up the carbon.    Don't worry about taking the carbon transmitter button out out of, or off of the transmitter bridge.     You can tap the bridge with the handle end of a screw driver and get the same results.     Just tap it a few times at all 4 corners of the bridge.    Secondly, I think your problem may be the rubber diaphragm insulating ring.   It's suppose to be positioned around the complete outer circumference of the diaphragm, not pulled across the diaphragm.     It's most likely dampening the sound vibrations produced by the voice of whoever is speaking into the transmitter mouth piece, and reducing the sound reaching the other telephone.
I'm not a salesman for Teleplay's ( John ) product, but if I were you, I would contact John, and send him the same picture you took, and that I've used here, and ask him to send you one of his diaphragm gasket kits.    I've bought some from him, and they're a quality reproduction gasket kit for transmitter diaphragms.    John will be able to see from the picture which one you need.
He charges a very modest price for the kit.    Once you re-install the kit with the rubber insulator gasket, make sure that the diaphragm pressure springs don't touch the diaphragm, or the back of the face plate, and rest only on the rubber gasket.       Then re-install your transmitter assembly and access the results of the repair.   

If you have any questions at all, just ask away.

Jeff Lamb

Offline Paul Boomer

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Re: Barely able to hear on one phone
« Reply #9 on: November 05, 2017, 09:37:14 PM »
 Jeff,

   How do I contact  John at Teleplay? Google was no help and I don't see a vendor section on this site.

  If it's just a thin rubber ring would the diaphragm material for a car fuel pump work? It's rubber with a cloth reinforcement, or does it need to be a foam? I have been restoring classic cars so I'm used to making round seal/gaskets.   Paul

Offline 19and41

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Re: Barely able to hear on one phone
« Reply #10 on: November 05, 2017, 10:36:38 PM »
Teleplay is his user name on this forum.  Private message him.
"Any sufficiently advanced technology is indistinguishable from magic."
Arthur C. Clarke

Offline TelePlay

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Re: Barely able to hear on one phone
« Reply #11 on: November 06, 2017, 01:40:57 AM »
Teleplay is his user name on this forum.  Private message him.

PM sent to Paul, thanks.

Offline Ktownphoneco

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Re: Barely able to hear on one phone
« Reply #12 on: November 06, 2017, 09:14:04 AM »
Paul  ....  I can't really provide you with an answer regarding the rubber gasket you use for fuel pump repair, without actually examining it myself.    Your also most likely to find that the back rubber gasket and the front rubber gasket were, at the time of manufacture, a one piece rubber gasket.     The back portion on your transmitter gasket appears to have ripped away from the front.    Reproduction or replacement one piece gaskets aren't available as far as I know, so it's a matter of using 2 rubber gaskets, one on the front of the diaphragm, and one at the back.    Just make sure that when you position the diaphragm, it isn't touching the painted brass face plate at any point around it's circumference, and is resting solely on the rubber gaskets.   The pressure springs once positioned and tightened down, will hold everything in position.

It becomes a bit of a pain to start experimenting with different materials to see if they work satisfactorily or not, because most of the time, it involves taking the transmitter assembly apart, make the change, then put it back together and try it.     If the results aren't up to scratch, then one needs to take everything apart again and repeat the process until one can achieve satisfactory results.
John's kit will provide you with the gasket that is positioned on the front of the diaphragm, which is visible in one of the pictures you posted yesterday.   

Jeff

Offline Paul Boomer

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Re: Barely able to hear on one phone
« Reply #13 on: November 11, 2017, 09:24:37 PM »
 Jeff & Everybody else,

  I got the gaskets from TelePlay and they fit perfectly but that must not have been the problem, still weak at the other end. I haven't had time to pursue it any farther because it got moved down the must do list. I hope to get back to it in the not too distant future.

Thanks to everybody that has rung in, all help is appreciated since I don't know stuff about how these work or how to diagnose them. I guess I was just lucky when I hooked them up and all was fine from the start.   Paul