A new filter/box is available. It has been built by A. Bettarini, under
contract from thr Arcetri Observatory. It is lighter, smaller and sturdier
than the filter/clock and offset boxes used till now. Construction of a
second model is foreseen in the near future.

The box is a small plastic container, with two potentiometers and a
push-switch. The two potentiometers allow the user to modify the offset
(fine and coarse, +/- 0.5V and +/- 10V respectively). The offset is
stabilized to a few parts in a million. The push-switch is used to select
4 fixed-cutoff filters, from 100Hz to 1000Hz (cutoff frequency shown
on the box). Characterization of the filters is under way in the lab.
Notice that only positions 0-3 are meaningful, while values of 4 and
above will leave the signal unfiltered.

The box has one input BNC, and two output BNC: one outputs the signal
with the same polarity as the input, the other reverses the signal
(remember that FIRPO has negative output). There is also a socket
for the power supply, which is a separate component including the
transformer.



				Andrea

Back to the following homepages: Lunar Occultations, FIRPO. Comments to luna@arcetri.astro.it