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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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rdelius

I would unplug the handset and short out the bk and rd connections on the network .You should hear static while doing this on other telephones on the same line. look at the wires that are connected and make sure that they are not shorted also

poplar1

Quote from: poplar1 on August 08, 2022, 09:14:56 AMYou 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.


Correction: If you can now transmit and receive (The receiver is temporarily  disconnected  )
"C'est pas une restauration, c'est une rénovation."--François Martin.

dsk

Between the jack for the handset and the circuit board it shall be 4 wires, probably Black, White, White and Red. The 2 white one is to the receiver that you allready know that is OK. If you take writ down where they are terminated, and unplug them, then connect a battery of 4.5 to 9V between white and Black, and connet the red and las white together you should hear yourselves pretty well. If not, unscrew the transmitter capsule and try to short the 2 springs in the handset, it should generate a loud click when you connect and when you disconnect. If so the the transmittercapsule may be bad, or only the springs who sould make contact to the capsule.

HowardPgh

Make sure the spring contacts are bent up to touch the back of the transmitter. That just happened to me on my new 1500.
Howard

MaximRecoil

Quote from: DannonWeb on August 03, 2022, 12:19:33 PMWhen 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.

How are you determining that there's nothing from the transmitter? You said you blew into it, which suggests you're listening for the sound of your breath in the receiver. You're not necessarily going to hear anything doing that. Have you tried making an actual call with it to see if the person on the other end of the line can hear you? If you don't have your pulse-to-tone converter yet, just have someone call you, or make a call on an extension phone and then pick up the ITT handset, or use a DTMF tone generator program on a computer and dial the number while holding the transmitter close to the computer speaker. Actually, that alone would be a test of the transmitter, i.e., if you can break dial tone by playing a DTMF tone into the transmitter, then the transmitter is working.

QuoteAnother 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?

If you've confirmed that the transmitter isn't working on that phone, even when using a known-working handset, and you said that you've confirmed that the wiring is correct by comparing it to a wiring diagram, then something might be wrong with the network. I would start by removing it and checking all of the solder joints on the underside of the PCB. You could also just try a different network. I think that this $10 ITT 2500 network is backward compatible with a 500 and that it will snap right into your existing plastic mount, but you might want to double-check with someone else before ordering it:

https://www.oldphoneworks.com/network-from-itt-2500.html

MMikeJBenN27

#20
Quote from: MaximRecoil on August 20, 2022, 11:11:45 AM...you said that you've confirmed that the wiring is correct by comparing it to a wiring diagram, then something might be wrong with the network. I would start by removing it and checking all of the solder joints on the underside of the PCB...
I would just replace that cheap network with a Potted network.  They are interchangeable.

Mike

MaximRecoil

Quote from: MMikeJBenN27 on August 20, 2022, 02:09:48 PMI would just replace that cheap network with a Potted network.  They are interchangeable.

I would too if it were mine and I planned to use it a lot, but it's not a drop-in fit and I don't know how much time/effort he wants to put into it. He would have to remove the existing plastic network mounting bracket, which looks like it's riveted in place, and then rivet the potted network in place (or use screws/bolts if he doesn't care how it looks), and I don't know if the existing rivet holes on a newer ITT/Cortelco base plate would align with a WE 425 network or not, so he might have to drill holes too.

I would also replace that plastic-framed ringer with an older WE C4 type ringer. I've heard those plastic-framed ringers before (I have a couple of them here), and I don't like the way they sound.

poplar1

Did you ever try replacing the gray modular handset jack (616D) that is on the base with one  (616W) from a spare handset, as I suggested earlier? I realize that it won't "look" right, but at least you can rule out a bad handset jack by doing this.

"C'est pas une restauration, c'est une rénovation."--François Martin.

MaximRecoil

Quote from: poplar1 on August 20, 2022, 06:23:58 PMDid you ever try replacing the gray modular handset jack (616D) that is on the base with one  (616W) from a spare handset, as I suggested earlier? I realize that it won't "look" right, but at least you can rule out a bad handset jack by doing this.

Or, if he has a multimeter, with the handset plugged in and the transmitter removed, he could test continuity between each terminal in the transmitter cup and its corresponding network terminal.

MMikeJBenN27

#24
Quote from: MaximRecoil on August 20, 2022, 03:03:16 PMI would too if it were mine and I planned to use it a lot, but it's not a drop-in fit...
The holes align perfectly.  I have done it several times.

Mike