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Wednesday, April 29, 2009

WSPRing Across the Mighty Atlantic

You have to look carefully, but in the picture above you can see a little green line stretching from Rome to Maine. That's my 20 milliwatt WSPR signal crossing the Atlantic. W1CDO's receiver picked me up at 0452 UTC yesterday.



Date Call
SNR


W
by loc km mi
2009-04-29 4:52 N2CQR
-22


0.020 W1CDO FN43ou 6541 4064

The day/night terminator was in the mid-Atlantic at that time, so I think I had a bit of a tailwind from the gray line! But still, not bad for 20 mw in Maunder Minimum II. K1JT's software and W1CDO's receive system did the heavy lifting. Antenna here is just an end-fed wire among the buildings of central Rome.

Goats Go QRP to the Field!



Another great video from Steve and the goats.

Monday, April 27, 2009

The Flea at MIT

Nick LaPointe sent along this nice virtual tour of the famous flea market (it includes four videos):
http://eepromeagle.dyndns.org/Pick/gallery/v/mitswapfest090419/

Nick also points us to the very interesting web site of Stephanie Maksylewich (VA3UXB): http://planetstephanie.net/

Thanks Nick!

Sunday, April 26, 2009

SolderSmoke 106 Podcast

http://www.soldersmoke.com

In SolderSmoke 106:

Sicily, Mt. Etna, The Godfather
DSB success on WSPR
Am I the lowest power WSPR station in the world?
Diode Ring Mixers
SolderSmoke: The Book
SolderSmoke: The Cologne?
And now, a word from our sponsor: Genesis Radio
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Our first sponsor: GenesisRadio

SolderSmoke is very pleased to have GenesisRadio of Australia as our first sponsor. Check out their site: http://www.genesisradio.com.au/G40/index.html

My very ugly DSB QRPP WSPR Rig

As described in SolderSmoke 106. My beacon box is the vertical aluminum box. The junk box AF Amp lies on the shelf. Like they used to say, "It's ugly, but it gets you there."

Saturday, April 25, 2009

Eldon's awesome 9V QRSS rig

Amazing! That's the whole rig, keyer chip included! And those red wires you see coming off the end -- that's the loop antenna. Here is Eldon's description of this rig:

For now, even thou it worked, I have abandoned the Water Tank QRSS Encoder, for a more traditional ID Keyer (K-ID2), and I have been busy rebuilding my 9 Volt Battery QRSS transmitter.

For my first approach, I wanted to use the Manhattan style of construction using mostly SMDs. The Oscillator was very successful even thou there were NO actual Manhattan Islands use, the components are just tacked-soldered together - I guess it would have to be called the "Ugly SMD Style".

Photos of Rev-0 are available on my web site;
http://qrss.ebcon.com/WA0UtWH/Gallery/Qx/

Setting the frequency was tough, as the some initial installed component's had to be replaced to get it to oscillate and adjustable within the 100Hz QRSS band. The "Ugly SMD Style" of construction is possible, but circuit changes are difficult. I decided to etch a HB circuit board to provide for a more physically stable "component selection breadboard", where SMDs part values could be easily tried, by just pressing them down in place (which BTW works very well). I then decided to expand the etched board to include space for the K-ID2 Keyer - with the goal of direct QRSS modulation with very few additional components.

This all worked so well, that I constructed another for a final form. Note: the second transistor in the photos is a 78L05 voltage regulator, which is used to help with long term oscillator stabilization, and used to reduce the power requirement and provide battery longevity.

The final QRSS Beacon uses a SMD 2N3904 for the oscillator and is now transmitting 1.5mW into a 18 inch loop antenna, currently only my grabber shows the results. But - My plan is to build this Beacon into the center insulator of a 30m Dipole and then start looking for QRSS Grabber DX. The battery should last several days at this very low power.

My goal is: to achieve long distance, with a very physically-small transmitter, small part count, and with extremely low power.

It will take me several days to construct and install the dipole antenna, until then you can see this Beacon sending "WA0UWH" on the Seattle Grabber:

http://qrss.ebcon.com/WA0UtWH/grabber/

73's - Eldon - WA0UWH
Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column