I bought an AT&T CL4940 corded phone. It comes with a power adapter. But I found it has a REN value of 1.2B. This really surprised me.
Why is this telephone having such a high REN value, even higher than those $10 very simple telephones that come without power adapter? Isn't it that nowadays telephones with power adapter, be it corded or cordless, should have a REN of only 0.1B?
That is a shock!
Some phones are designed to continue to work in a degraded capacity during a power failure. Could this be one of those?
So you mean all of the modern corded/cordless 0.1B-REN phones are NOT designed to continue to work in a degraded capacity during a power failure, and should be considered inferior to this phone, and a high REN value actually is a good thing, not a bad thing?
How can that be?
My Uniden cordless phones, which I am currently using on my OBi200 (0.0 REN, BTW) simply can't make or take a call without being externally powered. They are just dead. However, I have a nice AT&T desk speaker phone that will still work during a power outage. The speaker phone part won't work, nor will the fancy speed dials, but it will ring and dial out. Without external power, the phone has to draw power from the line to ring a bell, hence the non-trivial REN. I am simply suggesting that maybe your phone is designed to do likewise. Maybe not, but perhaps that's why it draws 1.2 Bels on a ring.
Designing a phone to work during a power failure is neither inherently good or bad. In this application, the tradeoffs are probably not desirable, but in a landline application, it may well be a different story.
I am not sure whether my phone:
(1) is constantly exhibiting the 1.2 REN value, regardless of whether being externally powered or not, or;
(2) is only exhibiting the 1.2 REN value without external power, and exhibiting a far-less REN when being externally powered. In another word, a dynamic variable REN.
The manual is not clear on that. If (2), then it is fine. If (1), then the AT&T engineers are too lazy and I hate them, as it will drastically reduce the number of phones I can plug into my OBI110.
Quote from: VOIP_JoeSummy on April 25, 2015, 05:46:03 AM
as it will drastically reduce the number of phones I can plug into my OBI110.
I'd just keep adding phones until I got to the number I needed & ignore what the manual says. ::)
Quote from: zorlac on April 29, 2015, 09:24:28 PM
Quote from: VOIP_JoeSummy on April 25, 2015, 05:46:03 AM
as it will drastically reduce the number of phones I can plug into my OBI110.
I'd just keep adding phones until I got to the number I needed & ignore what the manual says. ::)
... provided they all still ring. The OBi REN 5 rating is for system design... no point in deploying it to drive REN 10.
OE
Quote from: OzarkEdge on April 30, 2015, 05:46:04 AM
Quote from: zorlac on April 29, 2015, 09:24:28 PM
Quote from: VOIP_JoeSummy on April 25, 2015, 05:46:03 AM
as it will drastically reduce the number of phones I can plug into my OBI110.
I'd just keep adding phones until I got to the number I needed & ignore what the manual says. ::)
... provided they all still ring.
Ummm, kinda implied. ::)