[asterisk-users] Noise on FXS ports (Sangoma)

[shadowym]

I don't see any mention of you adjusting gains on the card/phones.  Also,
what are you doing for echo cancellation?  Can you post your zapata.conf
file?

-----Original Message-----
From: Stephen Bosch [mailto:posting at vodacomm.ca] 
Sent: Monday, June 04, 2007 10:01 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Noise on FXS ports (Sangoma)

Stephen Bosch wrote:
> Stephen Bosch wrote:
>> Hi:
>>
>> I have a Sangoma A200 card installed in a server with two FXO modules 
>> and one FXS module.
>>
>> Analog sets connected to the FXS module have a "squeaky static" -- 
>> it's like static mixed with the sound of someone vigorously cleaning 
>> a window a few doors down.
>>
>> In other words, it's not a classic static noise, but it is noise, and 
>> it's distracting. Remote callers can hear this noise.
>>
>> I have, by turns:
>>
>> - Tested the line with the same analog sets plugged in at the 
>> demarcation point. No noise. (None of the SIP devices in this 
>> configuration have this noise for outgoing calls, so I'm sure it's 
>> got something to do with the FXS module).
>>
>> - Plugged the known good analog sets straight into the server
>>
>> - Moved the FXS module off the REMORA daughtercard to the main card
>>
>> - Replaced the FXS module with a new one
>>
>> - Run the server off of battery power, to see if the noise is garbage 
>> leaking in off the AC
>>
>> - Turned off the PoE midspan
>>
>> The next thing I'm going to try is turning off the switch it's 
>> plugged into. When that is done, I'll have done everything short of 
>> move the server to a different location.
> 
> Maybe the power supply is generating this crap.
> 
> Hmn. I'm going to test this hypothesis.

Okay -- that didn't work. I swapped the power supply out with a better one,
and even disconnected the extra ventilation fan. The noise is different but
still there.

To those with experience with FXS modules, I welcome your input.

-Stephen-