If you want to have some fun and generate lots of high intensity
ultrasonic signals pass some high pressure air through a small orifice
or over a sharp edge.
Gedas, W8BYA EN70JT
Gallery at http://w8bya.com (under repair)
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 5/31/2021 8:59 PM, n0tt1@juno.com wrote:
Just rubbing your fingers together works very well. And yes, car
keys, walking in grass, bees, etc all generate ultrasonics.
Charlie, N0TT
On Tue, 1 Jun 2021 00:22:45 +0000 (UTC) AA5CT via RFI
<rfi@contesting.com> writes:
If memory serves me correct, playing around with an ultrasonic
receiver years ago I noticed that car keys gave off quite a bit of
'noise' (ringing and jangling) when shaken ... perhaps another
easy source to verify ultrasonic 'dish' operation in the field?
de AA5CT Jim
On Monday, May 31, 2021, 4:03:01 PM GMT-5, Charles Plunk
<af4o@twc.com> wrote:
Sit down and whipped up a 40khz oscillator. If nothing else gives me
confidence the dish is working. The dish is pretty much spot on and
if
go by max signal its very accurate at 30'. At some point need to
make
taps on the dish circuit for measuring max signal to make sure the
detector is in the right position in front of the dish. I'm guessing
it
is close.
https://www.facebook.com/media/set/?set=a.107413994889511&type=3
Chuck
W4NBO
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|