FIRPO MESSAGE #9
Last modified on August 25, 1997 by
A. Richichi
Notes on the use of the filter and clock, by S. Richter
From rich@tls-tautenburg.de Sun Aug 24 21:29:14 1997
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Date: Sun, 24 Aug 1997 21:27:22 +0200
From: Steffen Richter
Organization: TLS-Tautenburg
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There are also a few additional notes to the use of the new filter box:
The new filter box works fine. The two potentiometers allow a better
centering of the signal. But because of no linearity of the
potentiometers it is a good choice to use the potentiometer for fine
trimming in its middle position.
It is important to check that the new filterbox and the wave generator
for the ADC computer card use the same frequency. On the old
clock/filter box there was only one push-switch for both.
To get the same frequency for the ADC card as the old clock/filter box
use at the wave generator (you find it at the first flour in the 3.5m):
frequency: 500 Hz
amplitude: 2.40 V
offset: 1.20 V
DTY: 50 %
And do not forget to use a rectangular wave form.
For the photometry we used in August a frequency at the filter box and
ADC card of 100 Hz and at the chopper of 1 Hz.
For the LO a frequency of 500 Hz is OK.
Bye Steffen