REN values on Digital Voice

[RichHI]

I collect telephones I have many more phones than the REN 4 limit. All but one are dect cordless. So my questions are twofold:

As Dect Phones have a power source and a base unit also connect the ac supply do I count these as 0 or 1? If I turn off the ringer does this make a difference?

I have 4 Digital adapters which work fine though the BT phone (Elements 1K) take a couple of seconds longer to ring, perhaps this is because I have 2 handsets. I would like to put some more of my collection into use but thought I would check with the knowledgable folks in case I did something that messed up my line. I have had issues when all the adapters and the modem have to be rebooted before though that was caused by BT activity. Better safe than sorry. Would like to add 2 or 3 extra phones. I tried to get second line but it appears open reach now refuse to install them due to the pressure on FTTP. As I live in Surrey and we are the last people in the country to get any improvement, I think it will likely be another 2-3 years before we get FTTP. What is the answer? Can I add more cordless and if I switch off ringer will that make a difference? Thank you. 

[RIC9380]

You used to be able to buy a BT telephone extension REN booster which increased the power of the exchange ringing, allowing you to connect more products to your line.
The extension booster was capable of ringing up to 8 products connected to it but I'm not sure if it is still available or whether it would work with BT's Digital Voice phones. Someone else on here will surely will know better.

[Devon_Dave]

I suggest you get a small internal phone system. Take a look at the BT inspiration. 

You could give each phone it's own extension number, would need a bit or wiring work. 

[martin_z]

As it happens, I have a working BT REN booster which I'm about to list on eBay.  So if you're still interested in this, keep an eye out - it'll be listed in the next day or two.  A search for "BT REN booster" will find it.  And it will almost certainly improve things for you.

[martin_z]

Well, it wasn't the next day or two - life got a bit in the way!  But it's listed now, if you're interested.

[fosterl2]

I was an apprentice at the time, but REN (Ringer Equivalent Number) numbers came into existence when  PO Telephones first allowed people to connect their own devices to the network - part of the introduction of sockets (circa late '70s early 80's), rather than hard wired phones. Phones back then had a bell set and associated coils to operate it, and the the bell circuit was wired in series, whereas phones are in parallel. Due to the current drain of the bell sets, it was determined that a max of 4 (I think) was all that was permitted, due to the power drop in each bell set.

Modern devices do not use the bell circuit - they just sense the incoming ringing current, then electronically make a ringing noise, so then REN number is now totally superfluous and you can have as many devices connected as you like.

[Tim123]

If REN was only relevant to telephones with bells, how come even modern corded models (still on sale, such as the BT Decor 2200) still display "REN: 1" on the base?

[RIC9380]

Because the BT Decor 2200 is an analogue phone manufactured about 8 years ago for use on the old analogue public switched telephone network (PSTN).

[JB2016]

@RichHI 

This link may be of use to you:

https://bt-digital-voice.blogspot.com/p/bt-smart-hub-2.html