Wednesday, October 28, 2009

Successful QRSS Online

I tried my Centre Insulator QRSS Transmitter the other day without success, see: previous post.

Now it looks like, I may have been off Frequency (the band segment is only 100Hz wide!) - The Transmitter is subject to outside temperature, and the direct loading effect of the antenna. I may have NOT checked the Frequency after turn-on?

 The QRSS Transmitter - in it's nest.

Ready to be raised back to 15 feet AGL.

Tonight I retried the experiment (at 20091028 06:38Z), set the frequency, and - it worked!, I got a spot!,  .   .  .  .  I know - it was on my own Grabber?,  But, my Grabber is remote, 8 miles away.

This Transmitter has be measured at 43uW output with a calibrated RF Test Set, which make this a "1mile / 5uW" Spot,  or if my math is right and physics holds, that's "200miles / 1mW".

1mile / 5uW Spot

Now, to see if any other Grabbers will see my Centre Insulator QRSS Signal!  Note, I am not sure of the condition of the Battery, it was the last one that I had on the shelf.

My remote Grabber is at:

  • At 20091028 07:45Z, the frequency has drifted down to edge of the QRSS band segment, it may be a bad Battery, or the usual fast drop of the outside temperature tonight.

Update 2:
  • This next morning, 20091028 17:30Z - the little Centre Insulator QRSS Transmitter is still going strong, and with warmer outside temperature the Frequency has move back into the centre of the band segment.

  • Both, my signal and WA5DJJ can be seen, (along with some WSPR signals at the top).

Update 3 - 20091029 17:00Z:
  • Still running strong after 35 hours on the same battery! 
  • This now has become a "Die Hard" test!

Update 4 - 20091029 19:00Z:
  • Sorry to report, the little QRSS's DURACELL must be on its last gasps, the oscillator has dropped out of band segment at 20091029 18:43Z - we will continue to monitor until its last moments.

Update 5 - 20091029 19:20Z:
  • The little QRSS and DURACELL condition has stabilized, below and out of band segment, but stable. To continue to monitor the condition, the Grabber window has be moved down the band.

Update 6 - 20091030 01:00Z:
  • Amazing, The little QRSS and DURACELL just keeps "Going-and-Going" (wait, that's an EverReady slogan), the Frequency has moved up to the band edge and competing for space with WA5DJJ on the Grabber - Sorry Dave.

Update 7 - 20091031 00:00Z:
  • OK, I am still Amazed, The little QRSS and DURACELL has been running for 65 hours and has stablized at 10.140015mHz My other projects are on hold as I do not want to disturb this test, but I need the frequency to tune a new DC receiver , which will just have to wait.
  • The abrupt downward shift in frequency that was thought to mark the end of the battery, must have been a sudden change in temp or a rain storm incursion onto the circuit. Currently, I have no predictions as to test's contuned longevity.

Update 8 - 20091101 05:15Z - RIP:
  • The little QRSS and DURACELL has stopped, after running for 99 hours 15 minutes, during its life time it produced 4.267mWhr of RF Power. It called its ID in QRSS and CW 35,730 times.
  • It slipped off the Grabber at 10.139960mHz. 
  • I do not expect a recovery of any kind. It will be missed!
The Last Tx
Shown Faintly Near the Bottom

WOW, that was fun, Let's do it again!  . . .  sometime.

See the next post for the continuation of this adventures

E-Mails Received:

Dear Eldon,

Very interesting. That is amazing you could hold it on frequency hanging out there in the cold. I have to work very hard to keep mine on frequency. I thought the idea of hanging a solar panel  on it was a great suggestion.... then at least it would work in the daytime.

Your 8 miles / 43microwats figgured out to be 186,046 Miles per watt. That is 7.8 times around  the earth.... If I remember my Earth circumfrence correctly. So, I think that is one to put in your record book.

A ham I know put one of my Michigan Mighty Mites in a Great Stuff Cacoon. The great stuff really made it thermally stable. Then he launched it in one of his baloons and it went for miles and miles and didn't very much in Frequency. I thought that was a pretty neat way of doing thermal control.

Thanks for the look into your experiment. Glad to see someone else doing something interesting.

73 Dave

David R. Hassall WA5DJJ

Congrats Eldon for your uW experiments and blog.

I have running in my lab a 100 microW 30mt beacon.
The power is given from a 4x4 cm photovolaic cell.
Fluorescent lamps of the ambient is enough.
The oscillator is made with a BSS83 fet.

My challenge now a design a similar solar driven RX.
How far I could tranmsit and receive
a  modulated CW signal with theese  means ?

             Perhaps it sounds a little crazy.

                                       73 de IZ1KXQ


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