My new Frankenpayphone

[poplar1]

I hadn't noticed that when they chopped off half the ringer chassis, they also must have cut two of the ringer wires. If there are only two ringer leads--black and slate--there should be 1000 ohms between those leads, but if you had all four wires, there would be 2650 ohms between red and slate-red, for a total of 3650 ohms. If you have other ringers working, do you really need this one to ring, since the ringer is not original anyway?

[AdamAnt316]

I hadn't noticed that when they chopped off half the ringer chassis, they also must have cut two of the ringer wires. If there are only two ringer leads--black and slate--there should be 1000 ohms between those leads, but if you had all four wires, there would be 2650 ohms between red and slate-red, for a total of 3650 ohms. If you have other ringers working, do you really need this one to ring, since the ringer is not original anyway?

I haven't removed the ringer to see if the other two wires have truly been cut off, but will check soon. Would a ringer like this ring with just the black/slate wires used, or would the full coil be needed? As for why I'd prefer that it rang, someone seems to have gone to a fair amount of trouble to install a ringer in this thing (drilling a hole through the side of the coin vault housing couldn't have been a trivial undertaking), so I'd like to at least make sure that it can be made to ring if need be.
-Adam

[poplar1]

In the 1920s, ringers were often 1000 Ohms, but they drew about 2.5 times as much current as the 3650 Ohm ringers and required larger capacitors, typically 1 MF.

This ringer apparently worked with just the 1000 ohm winding when assembled by Long Island Telephone Co. Like the Jr. Achievement lamp makers, they butchered a lot of phones, but at the same time, kept them from going to the smelter.

[AdamAnt316]

In the 1920s, ringers were often 1000 Ohms, but they drew about 2.5 times as much current as the 3650 Ohm ringers and required larger capacitors, typically 1 MF.

This ringer apparently worked with just the 1000 ohm winding when assembled by Long Island Telephone Co. Like the Jr. Achievement lamp makers, they butchered a lot of phones, but at the same time, kept them from going to the smelter.

Yeah, that makes sense. Might using a 1µF capacitor in place of the 0.47µF one I'm using now help, or might that cause the ringer voltage to get drawn down too much as with the old condenser? What was the typical value of the condenser used for the coin control in these things?

When I got this thing, I feared the worst in terms of what sort of butchering had been done with it, but at least they left the coin chute mostly intact (albeit with a couple of cut wires). It'll never be perfect, but it's still got most of its parts, so there's a (slight) chance it could be returned to close-to-original someday, if desired. I'm glad L.I. Tel. Co. left it (almost) functional as a phone, at the least...
-Adam

[Phonesrfun]

None of the diagrams I have of various pay phones show a value for the cap.  They just show it in the circuit along with the resistor.  I have a multimeter with the ability to measure capacitors, and the one in my 233G measures 4.4 µF.  Its too bad they don't stamp a value on the can or show it in diagrams.  I assume the intended purpose of the RC in parallel with the relay is to keep the voltage spikes out of the line when the nickel lock-up relay releases.  Earlier versions just had the cap with no resistor.  The resistor in mine is 10 Ω, which I see yours is too.

4.4 µF is too much capacitance for the ringer.  The combination of the high value cap and the low value ringer coil make this a bad combination.  It would be best to see if the other leads are still on the ringer coil, or get a hold of a ringer from a Princess or Trimline coupled with a .5 µF.  The problem with using any ringer in the pay phone is that there really is no room.  Even though you have a chopped C4 ringer, it uses space in the coin vault area.  You would not be able to get a real coin box in there with any kind of ringer in the way. 

As an alternative to a coin box, I once used a tuna can to catch the coins.  The tin can approach at least will keep the coins from getting all over the bottom of the vault area and will also make that nice sound we all recognize when the coins drop into the coin box.  When they just hit the bottom of the vault with no can, it just isn't quite the same sound.  A can might work with a smaller ringer.  Many people have tried to incorporate a small ringer in the upper housing in place of the coin relay and screw it to the coin vane chute for support.  Most of those phones were just not designed to have a ringer inside.  One model does have a small ringer that fits up where the terminal strip on your phone is.  That model is a 235G. 

[AdamAnt316]

My guess about the lack of values of that cap (or, really, any part) on these phone diagrams was probably a way to discourage using generic replacement parts instead of Bell System-specified ones. Wouldn't surprise me, anyway.

I figured that coin cap might be too large, in one way or another. Would using a 1µF cap give any possible chance of the existing 1000 ohm coil winding to work? I checked the coil section of this ringer, and indeed, the other pair of wires (red and red-slate?) have been cut. I might be able to solder new wires to the connection points on the end of the coil form, but am not entirely sure how well that'd take. I am considering installing a different ringer, but don't know if the mounting point would still work. As I've said, I'm fairly certain this phone will never be original again, so I will let the butcher-job slide until I can find a payphone in better overall shape to keep/make original.

I have a small plastic box which happens to fit next to the ringer in the coin vault area, though the sides aren't high enough to shield the ringer against any dimes which fall errantly. As far as metal containers go, I might see if a metal junction box as used with wall switches would fit the area. If I can't get this cut-down C4 ringer to work, I'll indeed look into alternatives. The Princess and Trimline ringers hadn't been developed when these three-slot payphones were originally designed, but did come along in the later years of their production, so it stands to reason that some of them did manage to have ringers shoehorned inside. Did you mean the 236G, BTW? Can't find any reference online to the 235G,  and it seems quite close to what the butchers turned mine into (while still having a place for a full-sized coin vault, of course).
-Adam

[Phonesrfun]

235G is the one I am talking about.

You can go to the TCI library an search on 235G and pull up the diagram, or here is a link to it
http://www.telephonecollectors.info/index.php/document-repository/doc_details/3039-506-321-400-i1-coin-telephone-sets-235g-tl
The TCI library is a vast resource that has just about anything you'd ever want in terms of diagrams and Bell System Practices, and it's growing day by day.  Also many of the GTE, and other manufactureres too.  Best of all, it's free.
www.telephonecollectors.info


-Bill

[poplar1]

The 235G diagram shows 4 terminal boards (TB), a C4A ringer, and an 8M dial. Are you sure that it's not a flush-mounted panel phone, similar to the 2C but with 3 slots for the coins?

[Phonesrfun]

Yikes, I was talking about a 236G. 

[AdamAnt316]

Had a feeling it was the 236G. Anyway, I've gone ahead and removed the ringer, unsoldered the cut wire ends, bridged the slate wire to where the red/slate wire connected to the coil, and reinstalled the ringer. Now, do I have the ringer installed correctly? Here's a crude representation of how I have it wired, derived from how the original installation was done:

L1--------Red wire of ringer--------Red/Slate+Slate--------Black wire of ringer--------0.5µF capacitor--------L2

Is this how it should be? I found a diagram of a 685A subset (what would've originally been used with a 233G, of course) and it shows the capacitor connected between the red/slate and slate wires of the ringer. Will the ringer still work as I've diagrammed above? Would just like to make absolutely sure before anything else goes wrong. Once again, thanks!
-Adam

[poplar1]

If the ringer is good, then yes, it should work the way you have it wired. Do you now measure 3650 ohms between red and black?

[AdamAnt316]

If the ringer is good, then yes, it should work the way you have it wired. Do you now measure 3650 ohms between red and black?

My ohmmeter showed closer to 4K ohms. Might this just be a discrepancy with the meter, or could there be something wrong with the coil itself? At this point, little would surprise me...
-Adam

[poplar1]

Adam, just making sure the red/slate-red winding wasn't open. That would have been one reason for trying to make it work with just the 1000 ohm winding...So apparently they just decided to make up a new and "improved" way.

Hopefully, they didn't also guess at the talking circuit. You have more patience than I would have had; my first instinct would have been to remove all of the "patches" including the ringer and network and oversized washers/bolts where locks were supposed to be.

[Phonesrfun]

My ohmmeter showed closer to 4K ohms. Might this just be a discrepancy with the meter, or could there be something wrong with the coil itself? At this point, little would surprise me...
-Adam

4k is fine.  DC resistance on an inductor will not always show the resistance published.  I don't think there is anything wrong with the ringer or your meter.

[AdamAnt316]

I suspect that the as-received configuration was a fast-'n-dirty attempt to make the ringer work with the oversized coin control condenser (try saying that three times fast!). It kinda worked as a ringer, but probably drew as much current as several phones put together. In the initial testing phases with the old ringer setup, I had to disconnect four or five of my ringing phones from the line before I got movement from the clapper, and it was rather feeble at that...

I wouldn't have bothered rewiring the ringer, but noticed that the wires leading from the coil were soldered to four pads on the end of the coil itself. It was merely a matter of heating the solder, pulling the wire stubs away from said pads, then soldering a new wire to the red pad, followed by soldering the slate wire to the red/slate wire's solder pad. Still a bodge, of course, but hopefully closer to what the original spec for the C4A ringer should be.

As for the talking circuit, best as I've been able to ascertain, it seems to work like a normal phone would. A number of the terminals on the network are unused, but given that the backplate has its own terminal strip, I'm not entirely surprised. I haven't gotten any complaints on the sound quality, at the least.

I've mostly resigned myself to the fact that returning this contraption to original condition would be well beyond my meager restoration abilities, so I'll at least try and make it work as the 'refurbisher' intended. Hopefully I'll someday acquire a three-slot payphone which is closer to original shape than this one, but this will do for now. It helps that it works as a regular phone, since one of my self-imposed goals in collecting stuff is that everything I have can be made to be at least somewhat useful for my purposes.
-Adam