The problem are:

1) if you have a shielded cable and you don't connect the shield
it works as an antenna that will pick a lot of noise

2) if inside the shielded cable you have unused pairs
even if the shield is connected the unused pairs still works
as antennas...

regards
mauro

At 06:35 2006/06/09, you wrote:
>Hi J=F3n ,
>
>I am surprised that connecting the shield made=20
>so much difference.   I expected the twisted=20
>wire pairs to each channel to do a better job of=20
>maintaining channel and external isolation.
>
>Congratulations on solving the problem.   Thanks=20
>for sharing the information with us.
>
>Roger
>
>psn-l-digest-request@.............. wrote:
>>.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
>>| Message 1                                                           |
>>'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
>>Subject: Re: spike problem
>>From:    =3D?ISO-8859-1?Q?J=3DF3n_Fr=3DEDmann?=3D 
>>Date:    Wed, 07 Jun 2006 15:16:25 +0000
>>
>>Hi
>>
>>I haven't seen any spikes for last 24 hours. So I think this spike
>>problem has been fixed. I only had to connect the shield to the ground
>>in the amplifer board. Only noise I see now is normal culture based
>>noise.
>>
>>Regards.
>>
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