mufon ufo journal - The Black Vault

e initially operated in the PEAK
mode as discussed later in this paper.
The signal at the output of OA1 is
also passed via TRIGGER' LEVEL potentiometer
R7 to the gate of SCR 1.
When SCR1 fires, it activates alarm Al.
Since the power source is dc, Al will
remain on even after the triggering signal
has passed. Normally closed RE-
SET pushbutton S4 must be momentarily
depressed to silence the alarm. It
should be noted that the alarm will
continue to be activated repeatedly if
the detected object is still present.
Two modes of signal detection are
provided by PEAK/NORMAL switch
S2. In the NORMAL mode, meter Ml
will continuously show the signal value
output from OA1 when the detected
object is present (if UFO flux is variable)
and will return to null afterwards.
In the PEAK mode, the strongest output
level from OA1 will remain displayed
on meter Ml until the charge
on capacitor C3 leaks off. For this reason
C3 is selected to provide for the
best low leak characteristics. The charge
can be dissipated on C3 at any time by
momentarily selecting the NORMAL
mode. Two scales are provided on Ml
for OA1 output level, so as to provide
increased granularity of the detected
signal due to large or small field variations
induced in LI. These scales are
selected by HI/LO switch S3.
Operating power is obtained from
a line operated, regulated 12 volt dc
supply. If line power should fail, B2,
a back-up 12.6 volt battery supply will
operate the unit. Silicon diodes D3
and D4 provide for keeping the battery
voltage slightly lower than the
regulated power supply voltage and
thus allow its use only if line power
should fail. The unit is turned on via
ON/OFF switch S5. LED will illuminate
when power is applied via the regulated
power supply only, as it would
quickly aid in draining B2 when in battery-only
operation. TRIGGER
LEVEL control R7 should be set to
prevent the alarm from being triggered
by natural or man-made sources in
close proximity to the detector.
The construction and packaging
of the instrument is not especially critical.
The flux concentrator and coils
can be protected by a length of magnetically
neutral plastic pipe. Although
only the type of flux concentrator rod
mentioned above has been tested,
other rods may be used at a reduced
sensitivity as long as the magnetic per-
FIELD -INDUCTION MAGNETO METER,
Figure 1
LEO
meability of the rod substance is fairly
high (greater than 5,000). A list of
part numbers for a major retailer will
be supplied on request to simplify construction
of the instrument.
Left to right: Len Stringfield, Tom Deuley, and Richard Hall at Fund for UFO
Research table, 1980 MUFON UFO Symposium. (Photo: Bruce Oeuley)
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