My 302.

[McHeath]

Yah, give that a try.  I've not had any of my old phone collection have a poor transmitter or receiver.  If I have had problems with sound quality it has been sidetone, which a couple of my phones have too much of.  Also, the newer Cortelco phones don't like the DSL on the landline and even with filters installed give a slight hiss.  None of the older phones have troubles like that. 

[Stephen Furley]

Also, most carbon microphones of this sort of vintage are falling off in output now.

Removing the mic and giving it a couple of good taps can re-loosen the carbon granules and improve performance, correct?

That sometimes helps, but it wasn't necessary in this case.  Even with this treatment many of the older British ones are almost unusable in a 'phone for actual use.

I can't make out what the ringer problem is; after I unplugged it from the ISDN terminal adaptor I connected it as a normal PABX extension at work, and it rang.  About an hour later I tried again, and it didn't; it hadn't even been touched in between.  I've had a quick look inside, but everything looks ok.  Thinking about it, all of the American 'phones that I have, except for the CMC Trub-L-Shooter which has no ringer, have had ringer problems, and there have been many posts from other people with similar problems, but it's not a problem that I've had with my British sers.  Are American ringers more problematical?  There's no obvious reason why they should be.  I probaly won't do any more with it until I get the new cords.

[BDM]

I've never experienced but one truly bad ringer. They're not problematic here. There must be a difference in actual current or frequency. As far as issues with the microphones, yes. I've run into several over the years that simply needed replacement. I believe what happens is moisture gets into the carbon granules, causing them to "fuse". No "knocking" of the capsule solves this in certain ones. So, replacement is your only course of action.

[JorgeAmely]

I once had a bad AE40 ringer. One of the two coils was open. I took off the wrapping material off but could not find any obvious problem.

So I guess that at one time, something shorted the coil (defective, excess current, etc).

I didn't want to get rid of the ringer so it sat on my desk for weeks. Then I found a coil winder, so I removed all the original copper wire and rewound the coil with new wire and now it works. So far, this is the only defective ringer I have seen.

[Dan/Panther]

Jorge;
How did you come about determining the number of winds, or did you just fill it about to the same level ?
D/P

[JorgeAmely]

Hello Dan/P:

The other coil had a resistance of 2000 Ohms. I can't remember the wire thickness, but with that data, you can figure out who much wire you need. It turned out to be around 3500 feet of wire. I did 1500 turns at a time and it took about four runs to complete. At the end the overall coil thickness was a little too much, because the original wrapper did not fit, so I removed a couple hundred turns.

After that I checked it again and it was around 1900 ohms. Good enough for government work. Overall time to wind the wire was about two hours, but it must have taken much less when it was originally fabricated. In retrospect, I would have used less (or thicker) wire because these days ringers have about 3500 Ohms of DC resistance.

[McHeath]

So far I've only had one bad ringer, in a 354.  All the rest work okay, even the late model Cortelco ringers that use magnetic fields instead of an arm with a clapper work okay, and internet chatter is that they break often.  

[Stephen Furley]

It's not been the ringers being faulty, but other ringing problems.

WE 500:  Line cord had been cut short and a modular socket fitted to it.  A link between the yellow wire and one side of the line was required, and had been fitted inside this socket.  This link had come away at one end.  It was very difficult to replace this link as it was, so i replaced it with one inside the 'phone, which works fine.

AE 80: Corrosion on ringer spade terminal; worked after this was cleaned up.

SC 1543: 60 Hz. ringer won't work on 25 Hz. ringing current.  Not a fault of course, it was never intended to work this way.

WE 302:  Rang fine once, wouldn't ring about an hour later, nothing touched in between.  Can't see what the problem is; I'll look into it when I fit the new cords which I'll be ordering next week.

Over there you have the additional complication of ringers intended for various different frequencies, whereas here we have the complication of two different impedances of ringers, 1k and 4k Ohms, and of telephones being converted to a three-wire system when the new plug and socket was introduced in about 1980, with the bell capacitor being in the master socket, rather than in each telephone.  Extensions, both Plan 1a (hard wired) and Plan 4  (plug and socket) were very complicated with the old system, with master telephone, intermediate extensions and last extension (and intermediate and last sockets for Plan 4) all being wired differently.  The low-impedance ringers were wired in series so sockets on Plan 4 had to be designed to short out the contacts for the bell when the plug was removed.  I'm trying to put together a Plan 1a/4 system with 706 and 746 'phones, but I'm still missing a couple of minor parts.

Somebody here said that I could probably get the 60 Hz. ringer in the SC 1543 to work on 25 Hz. with the aid of a capacitor.  Does anybody know how to calculate the value required, and how it would be connected; in parallel with the ringer?

[Stephen Furley]

Bingster, what do you think about the dial being 4A?  Probably an "H"?  Until recently though I didn't know there was a 5E dial so there may be a 4A...I've just never seen one.  An "A" can appear to be an H to a guy that forgot his glasses.  Believe me, I can relate.

Yes, my mistake, the dial is marked 4H, not 4A.

[Sargeguy]

If it rang on one set of lines then it should be okay.  I suspect its probably your dodgy British phone service that is to blame.  Unplug all your phones and ISDN, including filters and see if you get any movement (watch the ringer itself).  Try fiddling with the adjustment wire and the bells and see if that does anything.

[Stephen Furley]

If it rang on one set of lines then it should be okay.  I suspect its probably your dodgy British phone service that is to blame.  Unplug all your phones and ISDN, including filters and see if you get any movement (watch the ringer itself).  Try fiddling with the adjustment wire and the bells and see if that does anything.

Sargeguy,

The line is fine, admittedly, it's supplying British standard ringing current (75V, 25Hz.) and the lower Voltage and higher frequency than the 'phone was designed for would cause the ringer to draw less current than it was designed to, but it must be able to cope with that, or it wouldn't have rung the first time on that current.  Nothing was changed between the time when it ang, and the time when it didn't; same line, 'phone hadn't been unplugged, or moved on the desk, it just stopped working.  My WE 500 and AE 80 also rang quite happily once I sorted out the connection problems; loose wire in one case, and corrosion on a terminal in the other.  The only one which I can't get to ring is the 60 Hz. ringer in my SC 1543, and it's not surprising that won't ring.

Let me tell you exactly what I did.  I plugged it in at home and didn't get a dial tone; found, and fixed, the loose wire on the handset cord.  Got dial tone, and made a call.  Then I took it to work.

There are no filters, or other 'phones or devices on the lines involved anywhere at work.  I first plugged it into an analogue telephone port on an ISDN terminal adaptor which was connected to a BT ISDN2e (ISDN BRI) line.  It worked, I made several calls, but did not try to get it to ring.  This was in one of our comms. rooms; I then took it to my office.  We don't normally use analogue 'phones in our office, but I do have one normal 'phone socket which I use to test analogue 'phones which I'm about to install around the building.  This is connected directly to the frame, where it is jumpered to a port on one of the line cards in the PABX.  I plugged it in to this socket, using four-prong to RJ-11 and RJ-11 to BT plug adaptors.  These adaptors connect the 'Tip' and 'Ring' wires (obviously) and also provide an earth connection on the yellow wire in the plug.  The extra 'bell' wire on a BT socket is not connected through these adaptors, and so the 302 doesn't see it; it's just a normal two wire line, plus an earth wire when it gets to the 'phone.  I called the 302, and it rang; I also made a couple of calls from it.  An hour or two later I called it again, and it didn't ring, everything else on it works ok.  I tried another 'phone in the same socket, and that worked fine.  I tried plugging it back into the ISDN terminal adaptor, and it wouldn't ring there either.  The analogue ports on the terminal adaptor are basically a self-contained analogue 'phone system; all tones, and the ringing current, are generated internally and, interestingly, the ringing current is to the American standard, 90V 20 Hz.  The line cards in the PABX supply ringing current to the British standard.  I then tried it on a direct exchange line, we have a few at work, and again no ring.  When it should be ringing there's no movement at all by the ringer, and if you move it by hand it feels just the same whether it should be ringing or not.

I then took it home, and tried it on my home line; this line does have ADSL on it, so there is a filter on that line; again no ring.  I had a quick look inside the 'phone, and there was nothing obviously wrong.  It's difficult to see which wires are going to the ringer, and the colours are badly faded, so I can't rely on them.  It must be a problem with the 'phone, nothing about the line it was connected to changed between when it rang, and when it didn't, and there's certainly ringing current on that line, I've measured it with the 302 connected.  I doubt that there's anything wrong with the ringer or the capacitor, and all the cores on the line cord are ok.  There are only three by the way, there was a black wire connected to the fourth wire in the plug but it didn't go anywhere, it was just an inch or two of wire coiled up inside the plug under the other wires.

Wednesday is pay day, so I'll be ordering the new cords for it then.  When these arrive I'll have a better look at it while I've got it open to fit the cords.

[Sargeguy]

Hmmm.  It sounds like the vibration from the ringing knocked something loose.

[Phonesrfun]

25Hz at 75 volts should work just fine.  Even hooked to a British system.  Either we drive on the wrong side of the street or you folks do, but the laws of electricity make more sense than traffic laws.

-Bill

[Stephen Furley]

Hmmm.  It sounds like the vibration from the ringing knocked something loose.

That's possible.  It's quite difficult to see which wires are going where.  It's pay day tomorrow, so I'm going to order the new cords tomorrow evening; they will probably take about 2-3 weeks to arrive.  I'll sort the ringer problem when I fit them.

[Stephen Furley]

Ok folks, I think I'm going to need some help here; I still can't get my 302 to ring.  I got the wiring diagram from here:

http://www.atcaonline.com/diagrams/WE-302.pdf

I connected a ringing generator to the pair of pins on the plug where the red and green wires are connected, the wider-spaced horizontal pair, normally next the the raised line moulded into the body of the plug, applied ringing current, nothing at first, then a very feeble ring, just touching one of the gongs and not quite touching the other for a moment, then even that stopped, and nothing since.  I then connected the generator to the terminals inside the 'phone where the line cord is attached, again nothing.

I now have the new cords, but haven't fitted them yet.  All six wires in the cords are connected as shown in the diagram, and I've tested the line cord wires for continuity.  I wanted to connect the generator directly to the ringer, and then to the ringer/capacitor combination, but that's proving to be difficult.  Apart from the cords, most of the wiring in the 'phone seems to be original, but the colours aren't as shown on the diagram, most of them are brownish; looks like varnished cotton.  On the diagram the two wires from the ringer go to the 'K' and 'GND' terminals on the small block; mine is not connected this way, there is only one wire on the 'GND' terminal, the modern yellow one from the line cord, the wire from the ringer doesn't go there, and I can't make out where it does go.  The fact that most of the wires are the same colour, and disappear under components permanently riveted to the base so I can't see where they go doesn't help.  I can't even remove the ringer; it seems to be fitted into a sort of frame riveted to the base, but I haven't been able to remove it from that.  I tried removing the horizontal screw between the gongs and under the hammer, but that didn't seem to do anything, so I put it back.

There are three wires going to each of the 'L1' and 'L2' terminals in the induction coil, two old original ones and one modern one from the line cord, rather than the two on L1 as shown on the diagram. The 'C', 'R' and 'GN' terminals each has one wire, as shown.  However, if the extra wire on L1 is the other one from the ringer then connecting the generator to L1 and L2 should ring the bell, and it doesn't.

Help!