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| 40m Log |
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 Tue Dec 4 23:16:35 2007, tobin, Update, PSL, ISS
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 Wed Dec 5 17:49:57 2007, tobin, Update, PSL, ISS 
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Wed Dec 5 18:22:03 2007, tobin, Update, PSL, ISS dark noise
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Wed Dec 5 20:32:51 2007, tobin, Update, PSL, ISS dark noise
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Thu Dec 6 19:30:43 2007, tobin, Update, PSL, ISS dark noise - 60 Hz!
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Fri Dec 7 19:14:30 2007, tobin, Update, PSL, ISS dark noise - ground loop enlightenment
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Message ID: 183
Entry time: Fri Dec 7 19:14:30 2007
In reply to: 177
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| Author: |
tobin |
| Type: |
Update |
| Category: |
PSL |
| Subject: |
ISS dark noise - ground loop enlightenment |
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My alleged 60 Hz harmonics were all from a ground loop created by connecting the SR785 ground to the ISS circuit ground; they disappeared when I set the SR785 input to "floating ground." doh!
I modified the ISS PD's to have a 100 ohm resistor in series with the output (in place of 20 ohms). The diodes are again in place on the table, ready for action. |