atcomsystems.ca/forum Forums General General Telephone & Systems Information antique phones don"t ring

Glaven. Where to begin...

1.) In reference to the circuit in your network interface, Arthur was talking about a half-ringer; it is bridged on the pair at the NIU to provide the equivalent AC impedance of ringer (and capacitor) equal to 0.5 ren. They are used for automated testng systems to provide a known impedance signature at a known point on the line, even if you disconnect everything on the customer side. I don't know about NY, but in these parts they are virtually unknown - I have never seen one on a Verizon or Frontier (nee Commonwealth) POTS line. The caution made against removing it was probably wise; if you don't know exactly what you are looking at inside the NIU you could wind up compromising the protectors.

2.) Sparky was both right and wrong: A standard mechanical ringer requires both sufficient voltage and sufficent current to ring. The nominal ringing voltage is 90VAC at 20 hertz; however later ringers will usually ring on as little as 60-70 volts. About 20-35 mA is a typical current draw.

3.) You are defenitely WAY over five ren with that nice collection of yours (Wow). Some of the ringers used in 300 and earlier sets were well over 1 ren each - remember that a mechanical ringer ren of 1.0 is for an F-type (or later) ringer with both coils in series.

4.) As was said, with older phones, standard bridged ringing was the exception, not the norm. Grounded ringing was standard for two-party lines and common on single lines, and then there were gas-tube polarized ringing and (in non-Bell areas) harmonic and decimonic ringing. Furthermore, just because a phone is WE doesn't mean it wasn't set up for the latter: I have here a standard WE 554, except it isn't a 554 but rather some odd numbered phone shipped by WE with no ringer installed for use in a non-Bell CO with frequency-dependent ringing (the ringer was installed by the purchaser, in this case Commonwealth Tel). Bottom line: get the BSP's (or KSP's, etc.) for all your phones and go over all the wiring and also verify the ringer type by looking at old catalogs, etc. An oddball frequency-dependent ringer might still ring if it is the only phone on the line, however when bridged with other phones none of them may ring because of the severe impedance mis-match. This is why real-world data comes in handy (see below).

5.) After you check all you connections and verify you ringer types, test each phone seperately on the bench to see how much current the ringer actually draws. Is use a late-madel Tellabs key system power supply that has a 90V 20 hertz ringing output, but any key system supply with a ringing output will do as long as it is 20 hz. (don't use a 30 hz. unit). Connect a good quality digital VOM (setup to measure current) in series with phone and see how much it really draws - once you've identified the phone(s) that are drawing too much, you can go on from there.

CAUTION : If you are not 100% clear on how to connect your VOM to measure current, you may want to skip this part. I don't want to blamed if you blow up your meter.

6.) If you want to ring all these phones, the ring booster is probably the way to go, but only after you verify the connections and ringer types. Another alternative is to swap out the ringers for later model units, there are some mechanical ringers which were quite small (such as the ones used in Princess phones).

Jim, Solid info but since our new member's tag indicates that he is green, I don't think he has any Tellabs ring generators laying around like many of us do. He should just try a combination of different phones to see just how many he can get going. I suggest starting with the newest phones first to see how many of those he can get to ring. Then, disconnect those and try it again starting with the older phones. Working forward and then backwards can give him a clue as to which phones he can have ring and which phones he should silence. A ring booster may be overkill. Besides, I think Hal wants to go over to help and play with these old phones. It certainly sounds like fun to me!

Well I have to tell you that the 202 will never ring and talk without a "bell box".

Never say never. Lots of them are out there, jury-rigged without a subset. The voice quality is awful, the clicks will kill your ear...but they are out there.

Wired many 201 and 202 sets with an Automatic Electric mini-network (from a Trendline phone) inside the base of the phone. No room for a ringer, but good quality speach.

so did I , wasn't there room in there for a 90v buzzer also ?

I seem to recall squeezing them in

Could it also be that the wiring in the home isnt consistant ? Dont the older 2500 (princess) phones need to be polarity sensitive? Just a question to put out there ? is he plugging the phones into the same jacks or moving them around ?

your correct AL , he early WE touch tone pads where polarity sensitive

I don't believe the ringing circuits where though

(BTW princess phones and 2500 sets are two totally different critters )

princess


2500

No, polarity has nothing to do with ringing, regardless of the age of the set. Ringing voltage is and has always been AC (alternating current), as in changing polarity anywhere from 20 to 30 times per second (frequency).

Reversed polarity only applied to touch-tone dials in early (approx. pre-1980) phones where this condition would result in the dial's inability to generate tones.

Princess phones were the 700/2700 series and they are long-gone. 500/2500 was (is) the standard desktop phone that is still quite readily-available today. You may be referring to the "Trimline/Trendline" series of phones, often referred to with the misnomer of "Princess" with the dial in the handset. These were often addressed with the 200/2200 nomenclature.

Thanks for the added input though. Every little bit helps in situations like this one.

Indeed the Princess is long gone, and while it was never my cup of tea, I know some ladies my age who would kill to have one now - they remember it, of course, as the phone they had when they were a girl.

As I remember, after divestiture, customers who rented/leased their home phones from Ma Bell were given the oppurtunity to buy them outright at a quite reasonable price - all except for the Princess. Those were held on to tightly by the Company, and were made available (refurbed) at the AT&T "Phone Centers." That simple little phone turned out to be quite a money maker!

Jim
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Still clutching my 2500 set and refusing to let go.