----- Original Message -----
Sent: Sunday, July 19, 2009 11:49
PM
Subject: RE: [PSUBS-MAILIST]
Take the time to go to: www.canakit.com and tell me anyone if you
have ever delt with this company and if so what were your thoughts after
having done so.
They seem to have quite a few electronic kits
that I could see a use for in the future with a wide selection of amplifier
kits. The three bandwidth spectrum analyzer is still shown and goes for a
little more than
$31.00.
David Bartsch
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject:
Re: [PSUBS-MAILIST]
Date: Sat, 18 Jul 2009 19:04:47 +1200
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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