Regarding the problem of intermittent chirp on receive in the Corsair II,
I have had the same problem and finally solved it.
It turns out that the circuit boards in the C-II have a special coating
used during the manufacturing process. With age, this material breaks down
and while the new compound is neither hazardous nor deleterious for
electrical performance, it does become a chemoattractant for several
members of the genus Teleogryllus. Further, a number of the internal
spaces in this rig turn out to be ideal nesting locations and it is not
uncommon to find quite a few individuals in residence.
Now it is well established that several species, including Teleogryllus
oceanicus, display a behavior known as evoked calling. That is, they are
motivated to produce an advertisement call in response to an acoustic
signal, even a fairly non-specific one. The call in this case is commonly
described as a "chirp". Thus depending on motivation of the individuals
involved (temperature, food availability, etc), each CW note will evoke a
call (chirp), i.e., the problem you are experiencing.
Fortunately, there are two relatively straightforward procedures commonly
used for fixing this problem. The first requires removal of the Corsair
II top and bottom covers and displacement of the individual specimens. Now
it is only required that males be removed, but unless you are an expert at
the procedure it may be difficult to make this discrimination.
Alternatively, the calling behavior may be discouraged by liberal
application of a corrective compound (e.g. Raid) with the somewhat
negative consequence of unpleasant odor.
Well that is about all you need to know. Please advice if this does not
help, as there are some alternative but more esoteric procedures which can
be undertaken.
73,
=Randy=
R. Zelick
Department of Organismal Biology
Portland State University
P.O. Box 751
Portland, OR 97207
503-725-3086 (voice), 503-725-3888 (fax)
email: h2rz@odin.cc.pdx.edu
web: http://odin.cc.pdx.edu/~h2rz/
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