[Asterisk-Users] X101P on a UK BT line ---- txgain issue

[Richard Scobie]

Chris Stenton wrote:
> Thanks for the info Rich looks like I'll have to wait for the new FXO
> module. The impedence in the UK is zcomplex(2) which looks a long way away
> from a straight 600 ohms.
> 
> Here is the list of zcomplex impedences
> 
>        Zcomplex(1) = 150 nF // 750 ohms + 270 ohms ( European harmonized,
> France Telecom & Telefonica )
>       Zcomplex(2) =230 nF // 1050 ohms + 320 ohms ( British Telecom plc )
>       Zcomplex(3) = 115 nF // 820 ohms + 220 ohms ( Deutsche Telekom  AG )
>       Zcomplex(4) = 310 nF // 620 ohms + 370 ohms ( Telecom New Zealand )
>       Zcomplex(5) =47 nF // 510 ohms + 150 ohms ( Russian Telecom )
> 

These complex impedances are all supported in the Silabs chips used in 
both the new TDM FXO module and the FXS module, but the driver currently 
sets them to 600 Ohms.

I guess at some stage a patch will appear to perhaps set these depending 
on the default tonezone set in the config files.

Regards,

Richard