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ITT 500 Suggestions for Transmitters Not Working

Started by DannonWeb, August 03, 2022, 12:19:33 PM

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DannonWeb

I picked up this beauty over the weekend and would like to get it working properly. It says on the bottom it's made in the US, so I figure it must be a Kellogg ITT. The phone rings great and I'll be ordering a pulse to tone converter to work with Comcast. However, I'm having an issue when I plug in handsets. When I try both the original handset and a modern one that I know works, the transmitter is not working on either. I can hear in the earpiece receiver, but when I blow or speak into the transmitter there's nothing. Another issue is that the volume in the original handset receiver is very low - you can barely hear the dial tone or someone speaking on the other end of the call. The wiring all seems to be okay inside the base when I opened it up and checked it versus a wiring diagram. Any suggestions?
ittrotaryphone.jpg

LarryInMichigan

It could be a problem with the shunt contacts on the dial.  Does the situation change when you rotate the dial slightly?  Have you checked the wiring connections inside the phone?  What happens if you temporarily disconnect one of the white wires coming from the dial?

Larry

DannonWeb

Hi Larry. I'll try to disconnect one of the white wires from the dial tonight. There's no change in the situation when I try using the dial, and the wiring connections seem fine according to a wiring diagram - nothing loose in there either. Thanks!

DannonWeb

I unhooked one of the white wires from the dial, but no change. I've included a couple inside photos.

MMikeJBenN27

Try wiring it is if it was a non-dial unit - Remove all 4 dial wires from the network and move the Slate-White wire from "F" to "RR".  If it is the dial assembly, phone will now work fine.  If it still does not work, and a different transmitter capsule does not help, the problem is probably in the network.

Mike

DannonWeb

Hi Mike. Thanks for the suggestion. I did as you said - disconnected the 4 dial wires and moved the sl-wh wire. Unfortunately, no change in the issue. The original and new handset are both still not working (no transmission of voice/sound). I can hear through the receiver end good, but nothing goes through the transmitter end. Dead.

If anyone has other suggestions, please let me know. I may have to send this out to someone to take a look, and hopefully repair it.

Dan

MMikeJBenN27

Are you sure the handset cord is good?  Those modular cords aren't the greatest.  If it is, then it must be the network, that thing with all the wires connected to it.

Mike

DannonWeb

I've tried multiple handsets/cords with the same result, unfortunately.

TelePlay

Did you take the transmitter cap off, clean the contacts with card stock paper and then pull up on the spring contacts to make sure they are in contact with the transmitter element when the cap is screwed back on?
Yesterday eats you up, it eats everyone up . . .

DannonWeb

Hi. Yes, tried that first before moving further into diagnosis and trying different things. Even other newer handsets present the same problem: transmitter not working, receiver ok. Thanks.

poplar1

Haven't  seen any photos of the jack that the handset cord plugs into. Are all 4 gold pins clean, spaced equally, and about the same height, when you are looking into the opening of the jack from the left side of the phone?
"C'est pas une restauration, c'est une rénovation."--François Martin.

TelePlay

Quote from: poplar1 on August 06, 2022, 08:56:23 PMAre all 4 gold pins clean, spaced equally, and about the same height, when you are looking into the opening of the jack from the left side of the phone?

Good point.


So, do you have a DVM (digital volt meter) so you use to can check the conductivity of that handset jack from the pins to the terminals each wire is connected to on the network?
Yesterday eats you up, it eats everyone up . . .

DannonWeb

Good suggestion. I played around with the handset plug pins, checking even spacing and height. However, still no luck. After the handset is plugged in a while, the pins settle into the positions seen in the attached photo.

poplar1

You said you have extra handsets. You can borrow the jack from the spare handset as a temporary replacement for the jack shown in the photo.

Just disconnect the jack from the spare handset (after removing the cotton ball, if any, in the receiver end) and connect it inside the phone the same way the exsting (defective?) one is connected: white and red wires to R on the network, white (or green) to GN on the network, and black to B on the network.

If you can now transmit and receive, then this confirms that the pictured jack is defective.
The 2 inner pins are for the receiver and the 2 outside pins are for the transmitter.
"C'est pas une restauration, c'est une rénovation."--François Martin.

HowardPgh

Lift the network out of the holder, it just snaps in. Look  to make sure nothing got under it to short it. Also check the solder connections on the printed circuit.  I don't like those PC networks, they are too hard to wire, and you can't see the terminal designations easily.
Howard