BELL Old Rotary Phone

[Bill]

A couple other questions.

The title of the thread is BELL rotary phone. But this doesn't appear to be a BELL phone. Or is it?

In the first post, you mentioned the resistance of the ringer.

I have also tested the ringer with an ohms meter and it looks ok. I got between the black and slate 970 (meter set at 2000) and between the red and slate/red I got 2.62 (meter set at 20).

First question - the meter in your photos doesn't have a "20" scale for resistance, so I am confused about that. Did you mean "200"?

Second question. When you measured these resistance values, did you disconnect the ringer wires from the connections within the phone? If not, how about redoing it? The 970 ohms is more or less in the ball park, but the 2.62 is way far out.

Finally, I think all the connection info you need is here.
http://www.kadiak.org/tel/ne500-554-2500-2554.jpg
You have a standard set, so you can ignore all the variations in the little figures.

Bill

[oskar270]

I like to say that the rotary phone was given to me by Bell when I first move to Montreal in late 70's and has been with me since then although I hardly use it because of the newer phones which became popular later. I kept it because I hardly through away anything.....

As I mentioned in my 1st post, I was told that maybe the capacitor was gone on the ringer and therefore I connected a new capacitor (0.47mfd / 400V) between the slate and slate/red but then I remove it because noticed no difference and the ringer still was not working.

Regarding the ringer wiring all are as you say Larry except the black from the ringer is going to F. When I put this to L1, the ringer still does not work and my voice sounds like echo when I talk.

The resistance between the red and slate/red is 2.57 and between the black and slate is 0.95 (both with the meter scale switch set at 20K)

Never felt the clapper if it vibrates when the phone rings but I was pretty close with the phone cover removed and saw no movement.

Have to get someone to call me to measure the voltage between the L2 and K terminals (tonight) because I have no cell phone.

I will do as you say if I have no voltage; is the capacitor I have (0.47mfd / 400V ok or I should buy another one?).

I don't think the ringer is bad because I was told to do an ohm test and it looked ok. (I get between the black and slate 970 ohms, switch set at 2000K. Between the Red and slate/red I get 2.62 ohms, switch set at 20K scale)

Thanks Bill for the C4A ringer pdf document, very informative and I have to read it more carefully to digest everything properly.

The 6 wires going to dialler are connected under the dialler to a small relay. I have to remove the dialler and the relay to see if there are any terminal markings at the bottom of the relay and I doubt it because this bottom is too small to have space for 6 markings. I think the relay came with the wires sticking out. If you insist I will take the dialler and remove the relay to see what is under there.

You are right Bill, the 3 wires going to the "PHONE" should read "HANDSET" sorry, not familiar with phone terminology.

I have no idea where the capacitor / condenser is and yes perhaps is internal somewhere. Also these blue / orange disks I have no idea what they are and I mentioned in my previous post their ID. Each of these disks is about 5/8" diameter and have 2 tiny wires at the bottom going inside the base of the network module and there is no ID where they are going. Their colour must mean something but I don't know that something.

My ringer does not have the ringer cutoff tab bent.

Let me know if there is any other info you want

Thank you both

Was ready to send the email and noticed you new email Bill. Yes you are right that the only problem with the phone is the ringer which does not ring.

I have no idea about capacitors and when I went to the only electronic store in my area I asked for a 0.45mfd /300V capacitor and they gave me this one, photo attached – capacitor next to a dime, 0.47mfd / 400V. I assume it was what I asked for. I must add that this store is like an electronics warehouse with items stored in bins and you must know what you want otherwise the limited sales people there know almost nothing about the items they sell

I will do the re wiring as you say but a few questions before: so the capacitor I have is not the right size? You want me to get a 1 uF capacitor? What voltage? How about if they don't have 1 uF? Can you give me a range? And since I don't trust the sales people there is it possible to give me an approx. physical size of this capacitor? Size like a quarter or 1" or what?

In that case I will have to go to the store tomorrow and get one assuming they have one and then I will do the re wiring and report back..

Thanks again

[oskar270]

You are right again Bill, I got the phone from Bell but it is a NE or Northern telecom

Sorry I don't know how to read the meter but the ohms scales are: 2000K, 200K, 20K, 2000, and 200. So I do have a 20K scale.

Yes when I took the reading all wiring for the ringer was disconnected from the network. And to do it again here are the numbers:
Between black and slate: 945 with meter set at 2000
Between red and slate/red: 2.55 with meter set at 20k (I was told to set the meter at 20k and the reading should be 2650 ohms +/- 10%) but I get 2.55. Perhaps that is the problem?

Thanks for the wiring diagram, have to study to see what I can find

[LarryInMichigan]

2.55 most probably mean 2.55KΩ, which would be correct.

[oskar270]

Sounds good Larry, thanks

[Bill]

As Larry says, the resistance of the ringer coils looks good, and you measured it properly. As for the capacitor, 1 uF is kind of a generic value for a ringer. It is not critical, and your 0.47 uF should be fine, assuming that is really what it is - and I guess we have to assume that it is. If there is no ring stop tab, and you do the rewiring and the ringer doesn't even vibrate, then I am at a loss as to how to proceed.

The orange disk and the gray/blue disc are not the capacitor - instead, they are the varistors listed as RV1 and RV2 in the diagram. So we still don't know where the ringer capacitor is.

Do you have another 500 set? If you plug it into the same jack, and call it, does it ring?

Bill

[oskar270]

ok tomorrow I will use the same capacitor I have and see the results.

Regarding where the existing capacitor is I want to ask you what is inside this network plastic box? That is the box shown on the photo in my post #13 where all the terminals are on top of it (L1, L2, etc.). I always wonder what is inside of it. It is about 2" long by 1" wide by 1" high. There must be something inside and may be that is where the capacitor is?

I don't have another 500 set neither anyone I know.

A friend will call me tonight and I will measure the 90VAC Larry asked me to measure between the L2 and K terminals.

I don't believe that the capacitor is burnt on my set Bill. This phone is like new and has not been used a lot since I got it and I don't think that capacitors burn so easily. I don't want to sound stubborn but I quote from TIPand RING on his post "Proper line-in wiring for your telephone" under section "Technical Stuff" on this forum"
".......Now my spheel about the ground connection--not only was this important for lightning protection and transient line surge drain to earth, but was a key element to making the phone ring. Many posts are "I can't get my phone to ring" or the eBay seller saying "everything works, but the phone will not ring for an incoming call"....That's because the yellow wire in the mounting cord is 1/2 of the ringer circuit. In the old days, this was connected back to the ground terminal on the protector--which ultimately lead to earth ground and completed a circuit back to the central office's ring generator that sent out 90 VAC superimposed on the line at approx. 20-30 Hz.

So why's this important?  There's only 2 wires in today's circuitry. TIP and RING. Soooooo. you must either rewire the network inside your phone--move the other ringer wire from the GND/Yellow connection OR do what I do and simply tie the yellow wire in the mounting (base) cord to either the green or the red wire. For example, to get a vintage Automatic Electric (GTE) phone to ring with just 2 wires, you must combine the GREEN tip and the YELLOW ground wire together at the baseboard terminal jack.

The whole idea of even using a 3rd wire at the customers' premises was brought about for party-line ringing where you could connect many more phones one pair of wires but selectively have only one phone ring by alternating tip and ground and ring and ground ringer connections. (other equipment was used as well, but we'll save that for later)."

In addition the wiring diagram you sent me shows that the Yellow line connects to G along with the Black from the ringer

I still believe that my phone does not ring because I don't have the Yellow line connected on the incoming phone line. If I'm wrong can you please explain to me why to educate myself?

Thank you Bill for your help

[oskar270]

Well, I had someone call me and took the measurements as Larry said between the L2 and K terminals.

With the phone plugged into the wall outlet, I touch the L2 and K and I get 113VAC (the meter is set always to 200VAC scale).

When the phone rings (it doesn't ring but I know it should ring because I told my friend to let ring until I answer) I get between the L2 and K 131VAC but fluctuates between 113 and 131VAC

Don't know what these numbers mean, I just hope its something good

Into another subject pertaining to testing; many years ago I remember there used to be a 3 digits number I used to dial and that made my phone ringing to adjust the volume. I don't remember that number but does anyone of you know of any such number? It will make my testing of the phone much easier

[Bill]

Regarding where the existing capacitor is I want to ask you what is inside this network plastic box?

The capacitor may indeed be inside the plastic box. In fact, I don't know where else it would be. Any chance you can take a peek? Does the plastic box open up easily?

In addition, the wiring diagram you sent me shows that the Yellow line connects to G along with the Black from the ringer. I still believe that my phone does not ring because I don't have the Yellow line connected on the incoming phone line. If I'm wrong can you please explain to me why to educate myself?

The diagram I linked you to contains info for many variants of the phone. Your variant is almost certainly the 500 DR desk set - the second entry in the Table. It refers you to Figure 1 and Table 1. Figure 1 is the schematic diagram, of course, and as you say, it shows the black ringer wire being connected to G, which is the Yellow ground wire. But on Table 1, down at the entry for "Wall Line Wire", under "Bridged Party", it says to check Note A. And Note A says "Move Black Ringer Lead from G to L1".

The "Bridged Party" is the party that is "bridged" (connected) across the entire telephone line - that is, from Tip to Ring. All single line phones - and that is all phones today - are Bridged Party connection. And whatever service you have in your house is bridged service. In the old days, when there were actual party lines, there was also a "Tip Party" (connected from Tip to Ground), and a "Ring Party" (connected from Ring to Ground). These are also referred to in the table.

These tables are always a pain to interpret, but my interpretation of what I am seeing here is that the Black Ringer lead should be connected to L1, and not to G (ground / yellow). So I welcome your efforts to incorporate the yellow wire. I may find that I have misinterpreted the info.

I think the reading of 113VAC when the phone is not ringing is bogus. What you are really seeing is the DC voltage that is supposed to be present on the line (AC meters will respond to DC), plus some stray capacitive coupling from the power lines in the house. What do you get if you make the same measurement with the meter sets to 200 VDC? The expected value from L1 to L2 is about 90 VDC, though there is a lot of variability.

But that is another issue, and I think it is time for me to back out of this.

Bill

[oskar270]

I was able to remove the network PCB, see attached photos, but I can't open that box. I tried and looks like its glued or press fitted and if I forced it more I may break the PCB.

I also forgot to mention yesterday that by moving the ringer black from F to L1 terminal I also get an echo when I talk on the phone and therefore to me the ringer black must be on the F terminal where I get very good conversation but the ringer doesn't work

Obviously you know much more than me Bill and I appreciate your efforts to make me understand the phone wiring. But to incorporate the Yellow wire I must connect it first to the ground at the incoming lines to the house and this I can't do unless someone from you tells me that it's ok to do it.

With the meter set at 200VDC and the phone on hook I get 52VDC and with the phone is off hook I get 5.2VDC.

Thank you Bill for your efforts and the education I got from you. If no one else comes for help I might call Bell and tell them to come and make the bloody phone ring. I still believe that the problem originates at the incoming phone line.

[oskar270]

I just called the phone company and a technician will call me within 24 hours to discuss the problem. I hope they will fix it at no cost and when I know what was the problem I will post the findings.

However if there is a cost involved with the phone company, then I will close this subject - not worth it to me to spend any money

[oskar270]

The phone company said that they checked the line to my house and all is ok; if I want to have a technician to check the lines / phones inside the house the minimum charge is $75 + tax.

I'm not prepared to pay any money for this exercise especially since all my phones are working well (except of course for the black rotary phone which does not ring) and therefore this subject is closed for me.

My conclusion is that I don't get enough current on my incoming phone lines to get the ringer working