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Thats great David,- its evolving.
Found this pdf with a circuit diagram & description of
an add-on stereo channel selector.
This is a follow up on my suggestion that you could range
between hydrophones with a
channel selector, stopping when a noise is detected,
with LEDs indicating direction.
Regards Alan
----- Original Message -----
Sent: Saturday, July 18, 2009 4:32
PM
Subject: [PSUBS-MAILIST]
To all:
In an effort to test console
#6's transmit channel 18 watt amplifier, I found an opportunity to give the 18
hydrophone passive sonar array a test run also. Although this session lacked a
preamplifier, some simple conclusions can be drawn from this simple testing.
(Only nine of these hydrophones have thus far been
installed.)
I was concerned at first that during
periods of training from one location to another, the scratchy contact between
the stator brush and its track would cause undue static noise. Turns out that
the more one uses this thing, the better it is worn in smooth and no such
interference is heard!
The stator brush controlled
hydrophone selector switch assembly worked flawlessly and proved that direct
hydrophone to hydrophone comparisons are possible! This will allow for better
contact bearing resolutions once a more definite beam width can be determined
for a single hydrophone unit. By training back and forth between two
hydrophones in quick secession, one can determine into which hydrophones cone
of detection a contact is most likely to be found. (switch bounce from micro
switches inhibited this feature in the earlier hydrophone selector
unit)
Lacking any underwater transmitter at the time
of testing, I trained straight across my 20' above ground pool and by tapping
the sides at various placements, I was able to determine that the hydrophone
most closely aimed at this location did pick up this noise the best (I
repositioned the array and ran this simple test several times with this same
result with other hydrophones.) I now see the need for a volume controlled
varying frequency underwater transmitter to better isolate the exact beam
width of these hydrophones.
I will resume this
testing once a preamplifier, an 18 watt amplifier board of my own, and
suitable sound source are
secured.
David Bartsch
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