[asterisk-users] TDM400 with FXS some handsets not ringing

[Gordon Henderson]

On Thu, 6 Nov 2008, Mike wrote:

> Folks,
>
> I have a TDM400 with an FXS module.  I'm having some trouble ringing
> some phones attached to the device.
>
> I have a real el cheapo handset that cost me about 9UKP.  It works fine,
> I plug it into the Wildcard and call the channel and it rings.
>
> I have tried plugging in my BT Diverse 3016 cordless phone but it will
> not ring, although I can call out from it.
>
> I have also tried my GPO 332L (a rotary dial phone from the 1950's),
> this also does not ring however, I can pick up the phone and make a
> connection.
>
> Are there any limitations to the ringer on the FXS module?  Is there
> anything I can do to make my other phones ring?

Are you using a ring-adapter for the UK that includes the capacitor to put 
the ringing current on pin 3? Something like this:

http://www.voipon.co.uk/rj11-adaptor-with-ring-capacitor-p-278.html

Or take the output of the TDM card and punch it into a BT "master" socket 
and take the phones off that.

A lot of modern (ie. cheap import) phones don't need it, but some still 
do. My refurb. 746 needs this. (1960's rotary dial)

Gordon