Author Topic: REN - Ringer Equivalency Numbers  (Read 20152 times)

Offline Tonyrotary

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Re: REN - Ringer Equivalency Numbers
« Reply #15 on: September 21, 2009, 08:10:45 PM »
I tried looking up the info on google. Not sure what the P stood for since I could not fine anything about GTE REN numbers. But the A stood for a ringer then rang on 20hz. Then there are B ones that rang on another frequency. and so on. (on Ma Bell lines)

Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #16 on: November 18, 2009, 04:43:05 PM »
I wake up this topic again, The current drain or REN will wary, I have an simple 4 line pabx, it only rings one old telephone.
The REN has never been an issue here in Norway, but the old tel-co limited us to maximum 2 telephones + one external ringer.

Looking a little at ringers. Until 1953, "all" ringers was 1000 ohms (Dc resistance) in series with a capacitor of 1 microfarad. Then we got 2800 ohms in series with 1 microfarad.  (edit to 1 mfd)

So I did some measurements today.
Since I have no telephone with known REN I had to make my own definition of 1 "REN"
The base was us ARMY TA 43 PT
All the measurements was made at 25HZ and 86 Volts.
TA 43 PT :                                                     Impedance:    9686 ohm 0r 8,9 milliamp  = 1
1000 ohm ringer in series of 1 microfarad:   Impedance:    3547 ohm 0r 24,2 milliamp  = 2,7
2800 ohm ringer in series of 1 microfarad:   Impedance:    3048 ohm 0r 28,2 milliamp  = 3,2

All later telephones has been with electronic "ringers".

dsk
« Last Edit: November 19, 2009, 04:01:23 PM by d_s_k »

I have even got a regular New York number :-) 646 570 1796

bellsystemproperty

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Re: REN - Ringer Equivalency Numbers
« Reply #17 on: November 18, 2009, 08:16:44 PM »
The eBay seller is just crazy, that's all.  :D I had five rotary phones hooked (that rang) up before I got my PBX. Now, the PBX alternates the ringing across the house for an incoming call. One phone rings, then the next extension rings, and repeats back to the first, it is quite interesting, but allows me to have as many phones as I want hooked up because they aren't all drawing REN at once. I have at least ten ringing phones hooked up (I lost count), but only up to three ring at a given instant because each extension has no more than three phones.

Offline ntophones

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Re: REN - Ringer Equivalency Numbers
« Reply #18 on: November 18, 2009, 08:38:13 PM »
What happens if you exceed the amount? Will they just not ring?
I hadn't thought of that, when I hooked up a new 302 base. I have6 phones hooked up, but, one set to not ring.
D1 with 302 base, ae40, trimline princess, an old itt (the one that doesn't ring) and 2 phones that are new and do the electronic ring. Is that too much? They all ring fine that are turned on to ring.
--nto

Offline Phonesrfun

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Re: REN - Ringer Equivalency Numbers
« Reply #19 on: November 18, 2009, 08:56:28 PM »
I am not really sure what will happen if you go too far over.  Probably just weak ringing, and if you are on a regular phone line, maybe a trouble ticket would be kicked out at the central office for someone to follow up on.  Whether the phone company actually does follow up in this day and age, I don't know.

A typical WE 500 model phone has a Ringer Equivalence number (REN) of slightly under 1.0.  According to Ralph Meyer's book, "Old-Time Telephones", Old FCC rules were that the total of all the RENs hooked to a line could not exceed 5, but I really don't believe anyone at the phone company pays much attention unless the current drain during ringing gets to be excessive.  One thing is for sure.  5 or 6 phones all ringing at the same time can get to be noisy.

So, my guess is that if you add too many more phones, you might experience weaker ringing.  
-Bill G

Offline gpo706

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Re: REN - Ringer Equivalency Numbers
« Reply #20 on: November 18, 2009, 09:23:00 PM »
okay doaky,

I have 2 x 746's, 3 x 706's, a 554 and my 1C2 wired up  at the moment.

I get a weak ring from one of 706's, the 554 is on "off" switch, and the 1C2 rings like dandy.

So I disconnected the 1C2 (because the ring is nice but right next to my bed, and I usually find the debt collectors like to phone folks on constant backshift at 9.30am, but also it has crackle on the transmitter).

I used to have a booster but obviously the broadband provider don't like it, so sod em, I need to get a wiring loom and redo all my cables...

The REN doesn't seem to mean anything on this circuit, probably because all the phones I have are botched jobs which work and I'm frankly too scared to fiddle about with anymore.

Righty, off Sat/Sun/Mon gonna strip everything out and recable all my junk!
"now this should take five minutes, where's me screwdriver went now..?"

Offline Phonesrfun

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Re: REN - Ringer Equivalency Numbers
« Reply #21 on: November 18, 2009, 09:54:36 PM »
dsk:

I am no expert on REN, but according to Ralph Meyer's Book, an REN of 1 is an impedance of 7000 ohms. 

I am also glad you found Colin's (oldphoneguy) information.  I once built one of his "subsets" using a resistor and a capacitor built into the base of a 202.  It worked satisfactorily for what I was using it for.

-Bill
-Bill G

Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #22 on: November 19, 2009, 02:41:06 AM »
1 :) Thank you to Bill "sending me to" http://oldphoneguy.com/   I have been reading, and enjoyed my selves (current English?) with the downloadable pdf documents.
2 :) Whats happening if you connect too many ringers?

  • The telephones wont ring, or ringing will be weaker.
  • As with the PABX of mine, you may not get offhoock.
  • The monitoring of your line sees an error, and disconnect you until the error is removed.

:) You may not make an exactly measurement of REN, but you may measure the current on your line, this may give you a reasonable idea of how much you put on the line. (my guess is that the only way they could test it was this way).
When you put in a extra working telephone on your line, and something starts to behave in an unwanted way, you have probably put in one too much. Remove it, and everything is OK.

 :) :) :) I believe the UK way, to split up the 1'st (master-)socket to have a 3 ringer wire may be smart, This has a common capacitor! The wiring on the telephones is then as on ringers with ground return, and the third wire is the faked ground.

dsk

I have even got a regular New York number :-) 646 570 1796

Offline ntophones

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Re: REN - Ringer Equivalency Numbers
« Reply #23 on: November 19, 2009, 07:25:44 AM »
Do you alleviate the problem by just turning off ringers, then? Or, do you have to disconnect the phone?
It won't hurt your wiring, will it?
--nto

Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #24 on: November 19, 2009, 08:10:05 AM »
Turning off the ringer will on some telephones only affect the sound, and will not help.
On others it is a switch disconnecting the ringer. This will help.
You just have to try.

I have never experienced anything damaging my telephone line by putting in odd things in the circuit.

Some adapters from ISDN, or internet, may dislike old ringers, and rotary dials, and collapse.

My line has been ruined once, when a stroke of lightning hit the pole next to the house.
The fuses, and surge protection, was just evaporated! (still burnmarks on the wall 20 years later)
I had 3 telephones, 2 containing electronics, and a 1934 telephone, When I opened my 1934, the yoke was thrown out of its hings. After putting the yoke back, the telephone was in OK again. More trouble wit the other two (--> trash can). :)

dsk

I have even got a regular New York number :-) 646 570 1796

Offline ntophones

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Re: REN - Ringer Equivalency Numbers
« Reply #25 on: November 19, 2009, 11:31:04 AM »
Wow! They just made great phones back then, eh? :)
--nto

Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #26 on: October 14, 2010, 08:51:33 AM »
Hi, I have problems with determining an approx ren no of Norwegian telephones.
The only American telephone I have is an old TA43PT. .

If I knew the REN no of this, I could make a simple circuit and measure the current at e.g. 20Hz and make a factor telling the approx ren no.

At least that is what I think????


Tank you.

dsk

I have even got a regular New York number :-) 646 570 1796

Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #27 on: October 23, 2010, 02:12:02 AM »
I got a hint one place to substitute one REN with the load of 7 kiloohms, another place I was told 70.7 millamps at 75 V 25Hz.
So I have measured, at 75 V 25Hz:
  ;) The Ta43TP 7.630 mA = 0.7 REN
  ;) The German Amtsanschliesser 28.5 mA = 2.7 REN New data with right capacitor: 17.1 mA =1.6 REN! 
  ;) Typical Norwegian 2.8 kOhms ringer in series with 1 uF (EB model 1953) 12.4 mA = 1.2 REN
  ;) Typical Norwegian 1 kOhms ringer in series with 1 uF (most before 1953) 22.3 mA = 2.1 REN

So if the traditional Norwegian ringer is approx 2-2.5  REN it the limit of 2 ringer gives quite equal limitations as your max at 5 REN.

dsk
« Last Edit: October 24, 2010, 05:35:24 AM by d_s_k »

I have even got a regular New York number :-) 646 570 1796

Offline bingster

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Re: REN - Ringer Equivalency Numbers
« Reply #28 on: October 23, 2010, 02:35:19 AM »
Wow. The 2.7 REN of the German set is surprisingly large.
= DARRIN =



Offline dsk

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Re: REN - Ringer Equivalency Numbers
« Reply #29 on: October 23, 2010, 03:32:04 AM »
I am not sure why, but German ringing-voltage is 60V but Norwegian is 90V

This testing was done at 75V 25Hz.

dsk

Edit:
Looking at the Amtsanschliesser 33 ( Amtsanschließer 33  ) the capacitor was wrong, 2 μF instad of 1 μF.
New measurement: 17.1 mA =1.6 REN!  
Thanks for getting me using my brain again!  :D

I have always been looking at the coil resistance of ringer, but this ringer has DC resistance of 380 Ω !!

I have still an idea of this resistance is a measure of how sensitive the ringer is, but the greater current, and no windings the more sensitive it should be so  ???


dsk
« Last Edit: October 26, 2010, 01:53:59 PM by d_s_k »

I have even got a regular New York number :-) 646 570 1796