Hello.

The Y connector most likley does not carry the frequancy that your
sensor is sending to the amp board.

Regards.
J=F3n Fr=EDmann.

On f=F6s, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote:
> Some months ago I purchased a Geotech Instruments Helicorder RV-301B
> with the accompanying amplifier AR-320B.  It works just fine when I
> drive it using one channel from one of Larry's older amp/filter
> boards.  The input is from a Lehman-type horizontal detector utilizing
> a coil with 8k resistance. (hz1 detector).   =20
> =20
> I normally have the Lehman hz1 output going into a second,
> newer version of Larry's amp/filter A/D boards, and then on
> to WinSDR. =20
> =20
> Here is my problem:  I want to split the output from hz1 using a Y
> connector to both the WinSDR display and the helicorder so I can
> record analog and digital simultaneously.  When I do this, the
> helicorder stylus goes dead and the CRT display from the amp/filter/AD
> board displays rhythmic amplitude spiking.  There appeared to be an
> impedance mismatch, so  an EE designed a buffer amplifier for me with
> two outputs.  Unfortunately, when using the buffer amp, the helicorder
> stylus still is inoperative and the spiking again shows up on the CRT
> display from the amp/filter/AD board, just as before.
> =20
> I am at a loss at what to try next.  The Geotech Instrument people say
> they are too busy to give me any advice.  I am wondering if any of you
> using the RV301B helicorder has tried to use a split signal such as I
> described?  I would appreciate any suggestions from the PSN family.
> Thanks and regards,
> =20
> Al Hrubetz
> Dallas, Texas
> =20
>  =20
>=20
>=20
> ______________________________________________________________________



  
  


Hello.



The Y connector most likley does not carry the frequancy that your sensor is sending to the amp board.



Regards.

Jón Frímann.



On fös, 2009-08-21 at 18:34 -0400, AHrubetz@....... wrote:

    Some months ago I purchased a Geotech Instruments Helicorder RV-301B with the accompanying amplifier AR-320B.  It works just fine when I drive it using one channel from one of Larry's older amp/filter boards.  The input is from a Lehman-type horizontal detector utilizing a coil with 8k resistance. (hz1 detector).    


     


    I normally have the Lehman hz1 output going into a second, newer version of Larry's amp/filter A/D boards, and then on to WinSDR.  


     


    Here is my problem:  I want to split the output from hz1 using a Y connector to both the WinSDR display and the helicorder so I can record analog and digital simultaneously.  When I do this, the helicorder stylus goes dead and the CRT display from the amp/filter/AD board displays rhythmic amplitude spiking.  There appeared to be an impedance mismatch, so  an EE designed a buffer amplifier for me with two outputs.  Unfortunately, when using the buffer amp, the helicorder stylus still is inoperative and the spiking again shows up on the CRT display from the amp/filter/AD board, just as before.


     


    I am at a loss at what to try next.  The Geotech Instrument people say they are too busy to give me any advice.  I am wondering if any of you using the RV301B helicorder has tried to use a split signal such as I described?  I would appreciate any suggestions from the PSN family.


    Thanks and regards,


     


    Al Hrubetz


    Dallas, Texas