First Wireless Toucans POTA K-1178

Project TouCans made its first POTA flight this weekend! The rig made 51 QSOs! Alas, there were issues we get to fix.. Which is actually kind cool :)

What the rig did well

OK, the rig made it coast to coast, up to Alaska, and into Canada! Pretty impressive if I do say so myself.

You might n otice that the bottom of the irg is about eight feet off the ground.That might make it seem like our radiation angle for 20 meters would be pretty high based on this

Taken from Radio Antenna Engineering

The antenna is about 0.12 wavelengths off the ground, so the angle—and I'm being kind giving it that extra .012, but the twine was stretchy making that within the margtin of errorr for this back of the envelope estimation—should be about 60 degrees as marked by the red arrow. But, that's if the ground is flat. We were on the edge of a ridge. I know this because I kept having to chase the roll of butcher's twine down the hill. I used the SOTA map for nearby Mt. Tamalpais (CC-063) summit to show that the slope of the hill was about 18 degrees.

The units are in meters for run and feet for rise.

Then, we have

For simplicity, first consider an antenna on the top of a hill with a constant slope downward. The general effect is to lower the effective elevation angle by an amount equal to the downslope of the hill. For example, if the downslope is −3° for a long distance away from the tower and the flat-ground peak elevation angle is 10° (due to the height of the antenna), then the net result will be 10° − 3° = 7° peak angle.

--from the very fb "Antenna Height and Communications Effectiveness" by By R. Dean Straw, N6BV, and Gerald L. Hall, K1TD.

Taking that into account gives us 62 - 18 or a launch angle of about 42 degrees as shown in green circle above. The hill slope giving us the effect of having an antenna at 0.4 wavelengths up isn't a bad deal!

So! With our almost half a wavelength up antenna, the dinnertime QSOs looked like this

From there, it's slightly less shocking that the rig 0.12 wavelengths up reached the opposite coast, and Alaska, and was spotted in Hawaii.

Here's the QSO map for the first portion of the following morning.

Then, the gang and I took a break for oatmeal that they cooked—yes I am bragging. Here's the QSO map between the end of oatmeal and our hike down the hill to the bus stop to go home.'

Where the rig could improve

There were WiFi connectivity and rig noise—as opposed to QRM—issues throughout. Let's talk about the rig noise first. It wasn't awful. A lot of the QSOs shown above are at 339 from the opposite coast. At least one of them was also QRP. That's pretty good and pretty cool! By taping down the audio out wire to the battery pack can, I was able to get rid of some of the noise. The thing is that sometimes, all of the rig noise is gone. I'm working on making that the typical case. The next step will probably be to mount the headphone jack in the battery pack can. We'll see.

WiFi though! Geesh! It seemed to be getting swamped by the gang's cell phones. It was also just generally spotty, sometimes taking tens of seconds to respond. I need to figure out a better system. Towards that end, here are some things the gang an I will try over the next several weeks:

Pico-W WiFi Interference Characterization

We can test the keyer in a somewhat controlled environment in the houe. It doesn't know it runs the same firmware on and off the radio. We need to vary the following:

Distance between controlling laptop and Pico
Number of other WiFi devices present

Distance of those devices from the Pico
Amount of traffic being executed by those devices during Pico Operation

Pico-W WiFi Directionality

We can tape board to the cieling, point it at and away from the controlling laptop and position the Pico-W behind and in front of soup cans.

The Whole Experience

All in all, this was pretty awesome! We need to get stronger twine now that the rig is heavier. Then, we need to test out suspending the rig. We might do this in McLaren Park. We won't get as much data on QSOs since it won't be a POTA activation, but we will get to practice the pragmatic aspects of getting the dipole mounted rig up in the trees.

One final thought:

It was really surprising and unique not to have to worry about running into or tripping over any wires from the radio to the ground!

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