Where was ultrasound listening device featured? QST? Issue?
On 28, Sep 2008, at 11:13, RFI Services wrote:
> Oh Grasshoppa, you learn valuable lesson, "A Grasshopper"
> Mike Martin
> RFI Services
> 6469 Old Solomons Island Rd
> Tracys Landing, MD 20779
> -----Original Message-----
> From: email@example.com [mailto:firstname.lastname@example.org]
> Behalf Of Dan Zimmerman N3OX
> Sent: Saturday, September 27, 2008 4:59 PM
> To: email@example.com
> Subject: [RFI] False Alarm
> I was out trying to locate some arcing on my 20/17m relay switched
> which became noisy on 17m recently.
> I built W1TRC's ultrasound listening device about a year ago to try
> to help
> me track down noise around here, and I took it out to the backyard
> to see if
> I could hear some arcs and determine if I had to take the antenna
> down or if
> I just had replace some ground-level wiring or such, and I noticed a
> strange, loud noise coming from my shed's rolling door. I
> determined it was
> a reflection, and followed the path to a spot near where my cables
> all enter
> the house, where I found it VERY, VERY loud.
> It was sort of like this:
> BRRRRRRRRRRRRRRRRRRAAAAAAAAAAAAAAAAAP tic tic <pause>
> BRRRRRRRRRRRRRRRRRRAAAAAAAAAAAAAAAAAAAP tic tic <pause>
> the "Braaps" had a very square-wave character to them.
> So I look around, all I can see are wires... I figure I never remember
> hearing anything on the radio with that character, so I go back to
> around to different points in the yard listening to the Moxon.
> I get over near my tomato patch and all of a sudden
> BRRRRRRRRRRRRRRRRRRRRAAAAAAAAAAAAAAAAP tic tic
> BRAAAAAAAAAAAAAAAAAAAAAAAAPPPPP tic tic
> BRAAAAAP BRRRRRAAAAAAP BRAAAAAAAAP tic tic
> I search around and find that yes, in fact, my tomatoes are emitting
> louder ultrasound than my wire entry area was. Now I'm really
> stumped, I go
> upstairs in the house and point around, thinking maybe the neighbors
> something going and it just *seems* like it's coming from my tomato
> but no, I get up there and find I'm pointing at the tomatoes.
> I put on a tinfoil hat and told my wife that the tomatoes were
> ultrasound; her response was "we've got a backyard full of wires,
> it's not
> the tomatoes" ... ;-)
> I'm pretty sure she's right but I just have to go and check *one
> more time,*
> and that's when I found it.
> A grasshopper.
> Sitting on a tomato leaf.
> A structure on his back vibrating in time with the noise.
> I've got GrasshoppeRFI.
> - - - - - - -
> Anyway, the ultrasound thing works ;-) Build one, and when you're
> not using
> it you can hand it to your kids and let them have a blast finding
> bugs in the backyard... and you can have them find other noises
> too ;-)
> RFI mailing list
> RFI mailing list
RFI mailing list