Propeller 30m QRSS Received in Tasmania

Another DX report for the Propeller 30m QRSS Beacon, it has been received by Edgar - SWL in Tasmania, at 8355 miles.

Faint Propeller Signal Upper 1/5th

The Current Data Format
as Received by my Local Grabber

The transmit path map:

8355 Miles

For specmanship, that is (8355 / .0625) = 133,680 miles / Watt :-)

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Propeller 30m QRSS Received in New Zealand

Another report for the Propeller 30m QRSS Beacon, it has been received by Peter - ZL2IK in New Zealand, at 6992.5 miles. Peter incorrectly decode my CALL, but it was close.

 My Propeller 30m Beacon
Received In New Zealand

The transmit path map:

6992.5 Miles

For specmanship, that is (6992.5 miles / 62.5mW) = 111,880 miles / Watt :-)

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Propeller 30m QRSS Received in California

Another report for the Propeller 30m QRSS Beacon, it has been received by Mark - K6HX of the Brainwagon.com blog and can be seen on his Grabber.

My signal is shown about 1/3 down from the top,  the transmitted repeated pattern is above the white line (oops, all of the lines are white :-)

Beacon Signal Received
 at: http://qrss.info

700 Miles

The Propeller QRSS Beacon output at 62.5mW on 10,140060MHz, the current data format is:

• CW ID at ~15WPM,
• A Propeller Graphic,
• My CALL in SlashCode (i.e,. "/\\ /\ \\\\\ //\ /\\ ////" ), where "/" is a dit, and "\" is a dah.
• Followed by a WA Graphic

Of course, because the signal (and output format) is just software, it could change on a whim.

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Propeller 30m Beacon Received in Pensacola FA

My Propeller 30m QRSS Beacon is being received by the W4HBK Grabber in Pensacola FA, about 2206 miles, with only 62.5mW.

I know that Watts/Mile are not real specs, but,  2206/.0625 = 35296 Miles / Watt

W4HBK QRSS Grabber

My SlashCode ID can be see upper left above the red line.

The transmit path map is shown below.

2206 Miles with 62.5mW

Note: other Grabbers are located around the world, an index or Compendium is provided by I2NDT.

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Propeller 30m QRSS Signal Received in Las Vegas

With the help of a QRP After Burner (see previous post). That is: a power amplifier that boost my 3mW signal to a whopping 63.5mW, my Propeller 30m QRSS Beacon has been received 900 miles away by KK7CC Grabber in Las Vegas !!

KK7CC QRSS Grabber

My SlashCode ID is weak, but it can be seen and decoded above the red line.

The interactive grid map shows the path.

The Transmit Path

Here is the set up, Antenna Connection far left, Power Amp upper left, Low Pass Filter upper right, Propeller and Battery below. The PA is a simple un-tuned single IR-510 FET circuit, feeding a ~200 foot long Off Center Fed (OCF) Dipole at 60 feet high, strung East-West.

Update: The antenna was recently physical measure at 325 feet long and 90 feet high.

My Propeller 30m QRSS Beacon Station

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Antenna Adjustments

Early this morning, without a rain drop in site, I decided to check the new Antenna that Jeff and I installed yesterday (see previous post). When installed, the feed point did not line up with the apex of the roof and therefore the Ladder Line could be wind blown and touch the metal roof. I can fix that by adjusting the support lines.

I knew I was temping fate and the performance of the antenna, by adjusting it in clear weather. The Great Antenna Gods would not like that.

Starting at the far end, I released about 20 feet of support line and retied it off. By the time I had the extra line coiled an secured, it started to sprinkle, and by the time I got to the other end to take up the slack, it was raining! The Great Antenna Gods have once again provided the inclement weather to ensure the performance of this new Antenna, Thanks :-)

Back in the Shack (loft) I noticed that I must have raised the feed point a little higher than before, the proper drip loop was gone. Another adjustment is necessary, but that will wait.

Also, when the weather clears, I will attempt to measure the height of the Antenna, a little trig should do the trick.

The Propeller 30m Beacon has been running on this new Antenna, but no reports so far.

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Propeller 30m QRSS Spectrum

I had reluctantly attached my Propeller Beacon and new Low Pass Filter to an older 30m 1/4 wave vertical antenna near my Ham Shack. I know the Beacon output is very low power (3mW), but I did not know if the low pass filter was working as designed. I did not want my Beacon to disrupt others. But, it was attached, anyway.

Low Pass Filter

Yesterday, my friend Jeff - KO7M came over to help install a proper longwire/dipole antenna (see previous post), and I had plan to attached the Beacon to it. Jeff brought along his Spectrum Analyzer, so that we could take a look at the Propeller Beacon's output.

As expected, without the Low Pass Filter, the raw Propeller output fed into terminated 50 ohm load was full of trash and harmonics, which is VERY undesirable for a Amateur Radio Transmitter.

Raw Output
Without Low Pass Filter

After attaching the Low Pass Filter, the trash and harmonics were still there, but at much low levels, more than 40db lower, and unseen at the same scale. Now, I felt good about attaching the Beacon and Filter to the Newly Installed Longwire Antenna.

With Low Pass Filter Attached
The Single Spike Is the Fundamental Frequency
This is what a Transmitter Output should look like

Yet, when we looked at the spectrum via an open probe in the room, all of the trash and harmonics were still very much present.

Jeff got the idea that it was probably radiated from the processor itself. We wrapped the Propeller, Battery, and Low Pass Filter in insulating paper and then in aluminum foil attached to ground. Now, only the radiated power of the fundamental Frequency passing through the Low Pass Filter and leaking from the Ladder Line could be seen with an open probe. The open probe received signal was clean, the same as when the beacon was attached directly to the 50 ohm load at the Analyzer.

My Local View of My Beacon's Signal

My hope was to see my little 3mW Beacon on KK7CC's Grabber in Las Veges (900miles). But so far, no joy.

I have a previously built Homebrew Power Amplifier that I may try, it should boost the signal to 30mW, maybe enough to be received in Las Vegas.

My conclusion

I think the Propeller, with a Low Pass Filter, can be used for experiments with Amateur Radio Beacons. But as always, more experiments and data is needed to know how useful it will be. A report from a remote QRSS Grabber will help the investigation.

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Antenna Installation Day

Today we had a great day of Amateur Radio.

My friend Jeff - KO7M came over to help install a new off-center-fed dipole antenna. Until now (since my move), I have suffered with just a 30m Vertical at 0' AGL for all of my Amateur Radio needs.

Today, was the day to fix that.

Jeff arrived about 10:00AM, the weather was clear with some overcast, we ware concerned that the Great Antenna Gods were not going to be pleased, with an installation that was not properly bathed with enough bad weather to obtain our desired performance. We went ahead with the installation regardless, with the idea we may have to settle for less than optimum performance. But the Gods smiled on us and provide enough showers to complete the installation with the required anointment.

We used my Tennis Ball Launcher (see previous post) to put a line into two tall fir trees, about 300 feet apart. With one shot at each end we had antenna support lines up maybe 60 feet, the actual height will be measured in clear weather. We had a lot of branched to snake the support lines around, but with two people the task was not too difficult, it just took time.

The desired feed line locations was about 50 feet from one end. So the counter poise was cut to exactly 23.50937 feet (plus or minus a few feet or so) as maybe needed for 30 meters. We do not know how well this plan will work, but it is what we have, and it fits the space available.

The long wire side of the dipole was cut to exactly, . . . where Jeff  stopped un-rolling wire, near the other tree, maybe 200 feet. The center insulator was installed, the long wire and counter poise were attached to the Ladder Line.

Pulling on the end lines took the antenna into the air, and into the near by tree branches and shrubs. With a little work, strong pulls and a small line over the antenna, the limbs were cleared. The antenna was now hanging is a big loop between the trees. A few more strong pulls and it was in place. The feed line location did not work out as expected, but the Gods were making it difficult to make further adjustments.  We picked up our tools and guide ropes, and headed inside as it was now raining.

Jeff had to make one more trip outside in the rain, because we needed to snaked the ladder line into the upper story loft window. Once inside the ladder Line rans across the room, attached to the overhead support beam and onto the radio station area. Later I plan to run coax to just out side the window and into a balun for a match.

By this time, we were glad we were inside, and out of the rain.

Inside and with a quick cut of the ladder line, a twist of the balun terminals on the Antenna Tuner, and the receiver came alive with strong signals being heard, . . . The Great Antenna Gods must have been pleased.

Now, I agree with the stories that I have heard, "All Good Antennas must be installed in foul weather, if you expect them to perform well"  :-)

A very Fun Day.

Now it was time to put my new Propeller QRSS Beacon on the air, and that as a continued report will follow.

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Propeller on 30m QRSS - SlashCode

The Propeller SlashCode modifications (see a previous post) to the Dots and Dashes routines was easy, similar modification was necessary to the end-of-character and end-of-word (space) routines. I also added the standard QRSS3 code.

PRI dot | i

  case CodeMode
    CW:
        sendTone(50)
        delay(100)
        noTone
        delay(100)
    QRSS3:
        sendTone(50+4)
        delay(1000*3)
        sendTone(50)
        delay(1000*3)
    SLASH_CODE3:
      repeat i from 0 to 4
         sendTone(50+1*i)
         delay((1000*3)/5)

PRI dash | i

  case CodeMode
    CW:
        sendTone(50)
        delay(300)
        noTone
        delay(300)
    QRSS3:
        sendTone(50+4)
        delay(1000*3*3)
        sendTone(50)
        delay(1000*3)
    SLASH_CODE3:
      repeat i from 4 to 0
         sendTone(50+1*i)
         delay((1000*3)/5)

Note: this Listing has been corrected (several times)

My Local Grabber - QRSS3

My Propeller 30m Beacon is in the center, the short burst of what appears to be trash before the first SlashCode is actually my CW ID at about 15 word per minute, followed by my ID again in SlashCode, and then WA as QRSS art follows (twice).

The stuff at the bottom is several other stations mashed together, for a better view of their signals goto KK7CC Grabber site. My 3mW signal, with a poor antenna, is maybe a little too weak to show up on KK7CC Grabber in Las Vegas (about 900 miles), but I will keep trying.

Propeller code seems easy to write, I am impressed. Note: I should have be using variables for the timing, but that is JASMOP (just a small matter of programming :-)

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Propeller on 30m QRSS - Output Power

First - Happy New Year to Everyone, I hope all is well, or as good as it can be.

Another first - this is my first electronic measurement of the year. Julian - G4ILO ask (via comments) "what is the output power" of the Propeller 30m QRSS and low pass filter circuit.?

I do not have a power meter that measures that low, but I measured 1.1V p-p across an accurate non-inductive 50 ohm load. With P=(Epp/2x.707)^2/R, the measure power is; (1.1÷2×.707)^2÷50 = 3mW.

Scale = .5v / Div

I still need to measure the harmonic content, my friend Jeff - KO7M has a Spectrum Analyzer that I will use to report the results.

But, looking at the ragged output waveform, I am becoming less hopeful that the Propeller will be useful for RF generation for radio work. The Propeller may be relegated to just control of other oscillators and/or displays.

Note: I would have expected more measured output voltage, because the Propeller is sourcing from an active 3.3V CMOS circuit. I need to investigate more.

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