From: Stephen Hammond 
To: psnlist 
Sent: Mon, 16 May 2011 16:16
Subject: RE: Photos of your station


Hi Larry, here is the PSN San Jose hardware link
ttp://pw2.netcom.com/~shammon1/AptosStn.htm
teve
Hi Steve,
    It would be most helpful if you could give the period of your Lehman an=
d=20
also the period to which the vertical is extended from 3 seconds. It is usu=
ally=20
possible to extend the period below resonance with a 1/f^2 filter by x10=20
without running into noise problems. You can also do this for geophones,=20
turning 4.5 Hz geopones into 0.45 Hz ones!=20
    Regards,
    Chris Chapman








<=
TT>





=
From: Stephen Hammond <shammon1@.............>

To: psnlist <psnlist@..............>

Sent: Mon, 16 May 2011 16:16

Subject: RE: Photos of your station





Hi Lar=
ry, here is the PSN San Jose hardware link
ht=
tp://pw2.netcom.com/~shammon1/AptosStn.htm
Steve

Hi Steve,
    It would be most helpful if you could give the period o=
f your Lehman and 
also the period to which the vertical is extended from 3 seconds.=
 It is usually 
possible to extend the period below resonance with a 1/f^2 filter by=
 x10 
wit=
hout running into noise problems. You can al=
so do this for geophones, 
<=
TT>turning 4.5 Hz geopones in=
to 0.45 Hz ones! 
    Regards,
    Chris Chapman