Thursday, October 31, 2024

Hiking and POTA (Parks On the Air) operation from Arches National Park (US-0004)

Figure 1:
Double-O Arch
Click on the image for a larger version.
Earlier this month I had the opportunity to spend nearly a week in Arches National Park in south eastern Utah.  As the name implies, there are a lot of natural arches scattered throughout the area, the result of erosion occurring over millenia, the semi-porous sandstone eventually yielding the the inexorable forces of wind and water.

These trips to red rock country are not new to me:  I've been visiting this part of the state for more than 30 years now, having spent more well over six months cumulative camping, hiking and backpacking in this austere land.  On most of these trips, I have been in the company of other amateur radio operators - and that was the case here, as well.

Compared to other national parks in Utah, Arches is fairly small - on a few 10s of miles long and narrower than this in width.  Compared to some places I go, it's a bit of a "tourist" park meaning that it's fairly crowded with comparatively few developed trails concentrated in a few areas.

Figure 2:
Fins and more fins, backgrounded by the La Sal mountains
as seen along the "primative" trail.
Click on the image for a larger version.
When going to such places, I tend to do about as much hiking as I can - but Arches is comparatively limited, but one of the longer trail systems is that associated with Landscape Arch and Double-O arch.  On this hike I took the "primative" trail, separating me from the madding crowds - a much longer route over occasionally rugged terrain, occasionally requiring a bit of scrambling up or down slick rock:  Just the way I like it!

Over the course of a few hours I made my way from the campground to Double-O Arch where I met the rest of my group who'd taken the other trail where we stayed for a while before splitting again and heading back.  Altogether, I managed about 10 miles (16km) or so by the time I got back to camp.

With temperatures in the mid 80s (about 30C) I set up my radio in the shade of my tent and shade and started operating.

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Equipment:

Antennas:

The evening before, I had a bit of extra time around dinner and I took that opportunity to set up my portable antennas in the cooling evening air.  For this POTA operation, I eventually set up two antennas - the first one being my JPC-7 loaded dipole.

Figure 3:
Operating CW in the shade, on a portable table, using
a cast iron frying pan to keep the paddle in place.
Click on the image for a larger version.
I've discussed the JPC-7 antenna on this blog before (LINK) - and have used it for several POTA operations already with good results.  Since the last POTA operation I'd rewound the loading coils, replacing the original stainless steel wire with silver-plated copper to reduce the losses - I discuss the details about this HERE.  It's difficult to estimate how much improvement this change made, but it's likely in the general area of 3dB or so - only 1/2 "S" unit or so, but it's certainly worth a bit of hassle to improve efficiency on an already-small antenna.

A day after setting up the JPC-7, I also set up the JPC-12 vertical antenna (described here).  This antenna, too, has been refitted with a silver-plated loading coil as well:  With a few extra mast sections, a top-hat and resonant, elevated radials it also makes for an excellent portable antenna - albeit a bit more complicated to set up than the loaded vertical, particularly when changing bands.

Radio and power:

The radio - an older Yaesu FT-100 (with the CW filter from an FT-100D) which was powered by a 100 amp-hour Lithium-Iron Phosphate battery using a paddle from cwmorse.us - (link).  I've used this particular paddle ("Outdoor pocket double paddle with magnets") for several POTA activations and as before, I've used the same cast-iron fry pan for all of them to keep the paddle from sliding around - often ending up with a bit of soot on the side of my hand and wrist!

Figure 4:
The antennas - and solar panel.
There was no audible interference from the
now-modified solar controller.
Click on the image for a larger version.
Operating (mostly) on 20 meters I managed to make about 285 contacts - all but four of them CW with 277 of them counting as POTA contacts.  The operating position was almost as POTA as one gets:  Sitting in a chair, under a shade, surrounded by sand and red rock.

Mixing antennas with solar - with no QRM!:

 Figure 4 shows the "antenna farm".  In the foreground - just left of center - is the JPC-7 loaded dipole, using a studio tripod for support while in the background - to the right of center - can be seen the JPC-12 vertical with tophat.

Also in the foreground is a 200 watt solar panel - but you may be wondering if this would cause QRM (interference) from its controller:  The answer is NO - but this is only true because I've done previous work to add extra filtering to it.  Even with the antenna (particularly the JPC-7) right next to the solar panel with its controller, I could not hear any interference at all - but this is by design as I have taken steps to make it quiet, and you can read about the details to accomplish this HERE in a previous blog entry.

At this camp site there were two other PV systems in operation located some distance away from the antenna, but I could hear those.  For the one closest, I happened to have an FT240-43 toroid on hand and I was able to cram five turns (with connectors) of the cables from the two panels feeding it:  Predictably, this reduced the QRM somewhat (1-2 S-units) - but as noted in the blog entry noted above, ferrite alone will not likely solve such a QRM issue!

Figure 5:
Red and green auroras backgrounding the big dipper.
Click on the image for a larger version.
The "other" PV system - which was even further away - caused minimal interference so nothing was done about it - but since I'd used my only FT240-43 toroid, I wouldn't have been able do anything about it, anyway.

Red Rock + Aurora = More red!

As it happened, the sun did a bit of burping in the days leading up to and during this trip, the result being the repeated appearance of a visible aurora, the first appearing on October 7 when very visible red pillars appeared in the northern sky:  Scrambling to the top of a nearby bluff, we could see a bit of red and green in the sky along with the Big Dipper.

For the next few days we noticed something else:  On the first night, the sky was spectacularly dark - the Andromeda Galaxy being visible - but on the night of the first aurora and for a few nights thereafter it seemed as though we lost a lot of the "deepness" of the sky.  We also noticed that despite the lack of moonlight, we could see the surrounding landscape and make out large objects on the ground without needing additional light.

Figure 6:
Sky glow, lighting up the camp and environs.
Click on the image for a larger version.
We eventually realized that what we were seeing was sky glow.  In other words, the entire sky was glowing dimly:  Not bright enough to be perceived as color, but the cumulative glow of the entire sky was enough to illuminate the landscape in that odd way.

A few days later the aurora was clearly visible again - and that's when the photo in Figure 6 was taken, showing a bit of red behind the clouds to the north and some green glow on the northern horizon.


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This page stolen from ka7oei.blogspot.com

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