[Asterisk-Users] TDM400P Revision question.

[Robert Webb]

On Thu, 14 Apr 2005 12:45:44 -0400
  "Ian Pattison" <ianp at technologyassociates.ca> wrote:
> My specific issue has to do with ringing on my FXS 
>ports.
> 
> A Northen Telecom Harmony phone (circa 1983) rings 
>normally but when I connect my newer GE 2.4GHz cordless I 
>never get more than 1/2 ring (it lights up and works 
>fine... just can't get a ring from it). Normally I'd 
>assume that it's a low power issue on the FXS port but 
>with a phone rated at 0.1 REM?
> 
> I do have some strange voltages though....
> 
> ON-Hook: ~48V DC, 107V AC (this really concerns me...)
> Off-hook: ~6V DC, ~12VAC (where the hell is this AC 
>component coming from???)
> Ring: 0V DC, ~45V AC
> 
> Suffice it to say that electrically this is completely 
>out to lunch... I'd like to throw an oscilloscope on the 
>line to see what's what but I'm having trouble finding 
>one.
> 
> Thanks,
> 
> Ian

The one test I did not look at was off hook scenario. I 
will try that tonight. I am also going to call a friend of 
mine now and see if he has a line tester I can borrow to 
accurately measure the voltages.