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.

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!

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."

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

On to the Canary Islands

Got up this morning, walked into the shack and saw on my computer screen a thin green line from Rome to the Canary Islands. I knew that my little WSPR station had reached out to new territory, and had established a new distance record (for me). Life is good!
As I've been doing, I decided to see who was at the other end of that line. It was Luis, EA8AY (pictured above). Luis's station picked up my 18 milliwatt signal at 2106 UTC on April 24. The distance was 1871 miles (3011 kilometers). I was 23 db below the noise.
Luis has a very nice web page: http://www.ea8ay.com/index.html (Warning: This site will likely cause feelings of extreme jealousy: Luis is living in a fantastic location, with a beautiful family AND he is the owner of an Argonaut 509!)
On his site, Luis has a nice video that will give you a sense of what WSPR is like:


wspr with 100 mw from luis on Vimeo.

Crossing a small bit of the pond...

I got into WSPR because I wanted to one day walk into my shack and be greeted by a Google map with big long lines showing my milliwatt signal stretching bravely across various oceans. That hasn't really happened yet, but I got a taste of it this morning courtesy of OY3JE's WSPR station. Jan lives in the Faroe islands, about 1600 miles from me. Last night at around 2300 UTC my 18 mw WSPR signal made it to Jan's location. I was 29 db below the noise. Thanks Jan!
(The images above and below are of Jan's locations in the Faroe islands (from his site).

WSPRing along at 27 db below the noise....

WSPR is fun. I haven't crossed any ponds yet, but the real- time displays of the reception reports are very addictive:
http://wsprnet.org/drupal/wsprnet/spots
Be sure to click on the map display also.

I was intrigued by the Signal to Noise ratio column, and wondered what the reference bandwidth for the noise was. K1JT's pages show the reference bandwidth is 2500 Hz, and that WSPR can decode signals that are as much as 27 db below that noise.

That's great. I guess I don't have to worry about the lower sideband of my 30 mw signal causing anyone any trouble. It will be very far down in the noise.

Are Diode Ring Mixers Fundamentally Different?

Joop, PE1CQP, and I have been discussing mixer circuits, especially the ever-popular diode ring.
Here is my latest e-mail to Joop. The RSGB diagram for the ring diode mixer appears above.

Joop: I think the way the diode ring mixer works is very different from the way a two diode singly balanced mixer functions. The effect, of course, is the same. But the polarity reversing element introduced by the ring configuration -- it seems to me -- makes this a very different circuit.

Attached is the RSGB Handbook diagram I mentioned. I like it, because you can really SEE how the actions of the diode ring produce the sum and difference freqs (you have to keep Fourier in mind, and imagine the results of filtering).

The two diode circuit simply "chops" the input signal at the rate of the LO. And it would even work in a non-switching mode -- you could, for example, use FETs instead of the diodes and bias them to operate in the non-linear portion of their curves, right? This makes me think that the diode ring mixer circuits (aka "polarity switching mixers" or "commutating mixers") are very different.

73 Bill

Balloon! Project Blue Horizon Reaches Mid-Atlantic

Wow, that's an exciting track. The intrepid radio amateurs at Cornell University have a balloon up over the mid-Atlantic. It is approaching my old stomping grounds in the Azores. Beacons are onboard and reports are requested. Here are some more details:

Balloon Launch - Assist in Tracking

The NS3 group of Cornell University engineering graduate students will launch PBH-9 (Project Blue Horizon) from Lockheed Martin in Owego NY on Sunday evening, 19 Apr 09, at approximately 21:00 EDT (Monday, 20 Apr 09, 01:00UT)

This ARHAB flight (Amateur Radio High Altitude Ballooning) will ascend and then float for up to 50-hours while drifting to the east.

The payload will include a KC2TUA-8 144.390 APRS beacon
(track via (http://findu.com/cgi-bin/find.cgi?call=KC2TUA-8)
and HF CW position report and telemetry downlinks on 7.104MHz and 10.148MHz.

The NS3 PBH-9 team requests distant ground stations receive and report HF telemetry via N2XE@arrl.net including reception UT date and time.

Distant receiving stations are welcome to also submit HF
reception reports to W0RPK@amsat.org for the ARHAB <50mhz href="http://showcase.netins.net/web/wallio/ARHABrecords.htm" target="_blank">http://showcase.netins.net/web/wallio/ARHABrecords.htm.

Additional PBH-9 information including HF telemetry transmit schedule and format is available via
http://showcase.netins.net/web/wallio/ARHABlaunchannouncements.htm.

Flight updates are available from the NS3 PBH-9 team
via http://twitter.com/pbh3.