Summiting Sierra Estrella (Hayes) High Point 18FEB18

4514′ elevation – clean prominence: 3212′ – isolation: 47.4 mi

GPS log available at peakbagger.

Wireless communications site

View of peak from trailhead, high point / radio site not in view.

Looking east toward rising sun. Evil cholla forest.

Woolsey Peak in left center distance.

What passes for a trail here. (Wait! There is no trail!!!)

More of the fine trail.

There were cairns along the way every so often, but all they really did for me is let me know some other human had been here.

Looking back towards trailhead and vehicle. Still there!

It was somewhere around here that I stepped on a boulder that proceeded to roll, then I fell smack on my head. No blood, no lightheadedness, no visual effects, but most stuff in pockets all fell out on ground while I was momentarily upside-down.

The boulder-hopping was getting rough on the ankles.

Still more boulders. Really impressive the ability of water to move stuff.

Looking back toward trailhead, which is hidden behind stuff on the left.

Higher and higher I go. Coefficient of steepness approaching angle of repose in some spots…

Now it gets heinous. That wash below was the path I took to get here. The vertical may not look like much from here, but I’m scaling rock walls with some horizontal jointing and serious cacti and ocotillo to dodge.

I know how this bighorn sheep felt… Man, that was a tough climb to the ridgeline.

And finally, Sierra Estrella High Point comes into view. But, it’s still about 0.5 miles away, and continued boulder hopping required.

Now the last pitch. Another 300′ vertical. There is kind of a trail here, but it’s not much.

Looking across the canyon to what looks like a large mine adit on the opposite ridge.

Looking back in general direction of trailhead.

This is what the final ridge climb looks like, more or less.

Final pitch, getting closer!

Alrighty! About 7500 W of solar power just in this set of panels here.

Microwave link to the NW.

Top of the mountain at the facilities.

Not the real benchmark, I didn’t find it.

More radio links.

Radio towers.

Note the amount of wind power generation. However, none was spinning on this day. Guess not enough breeze.

Toward South Mountain.

More solar and wind power generation.

Imagine this is the way they get the big gear in and out of the building.

When all else fails, there’s propane!

Clean looking site, huh? Wonder how often the critters chew through stuff?

Three big bottles and one long tank of propane.

What I think is a helipad / drop point of sorts.

Another not-the-real-thing benchmark.

Looking back, about 45-60 minutes down from the peak.

Sierra Estrella near sunset, looking east.

Summiting Harquahala Peak on foot 31MAR18 – Wireless communications site and historical buildings

5684′ elevation – clean prominence: 4361′ – isolation: 42.9 mi

GPS log available at peakbagger.

Time-lapse dashcam video of drive from pavement to trailhead.

Wireless communications site and historical buildings.

View from the Salome Rd with Harquahala the tallest peak on the ridge. For 5 years, from 1920 to 1925, the top of the mountain was home to a Smithsonian Astrophysical Observatory facility.

Developed trailhead, with toilet, about 2 miles south of US60. There is a closed but unlocked gate for entry from the highway. Please make sure to close it behind you.

Easy drive in, even a sedan could make it as long as the driver takes it slow and easy, and doesn’t mind a few bits of desert pinstripe.

Harquahala from the north side.

Remains of historical facilities along the trail.

Gorgeous exposures of what appears to be some sort of metamorphosed granitic rock? Largest porphyroblasts are maybe 1 to 2 cm in longest dimension.

At the saddle, looking about NW.

At the saddle, looking about SSW.

At the saddle, looking about SW.

At the saddle, about WNW.

At the saddle, about SE.

Benchmark at the very top.

Benchmark again.

Looking down toward dirt/gravel road that comes up the mountain from the SE side, though the view is about SSW.

Simple radio site closest to the benchmark. Not sure what frequency band it is or to what entity it belongs.

Big solar powered radio facility belonging to Central Arizona Project.

Some sort of historic structure to the south.

The site is mostly used as a microwave hop point, but there’s obviously a number of two-way radio and telemetry stations atop the mountain.

Nice place for a picnic. Note the rock fireplace complete with grill for cooking some steaks.

Next few are Flood Control District of Maricopa County. The data is on-line here.

Helipad complete with four ground-embedded red beacons.

SW along ridge from benchmark.

NNW from benchmark.

NNE from benchmark along the ridgeline.

While true in general, a bit bogus here as no one was using heliographs for the Central Arizona Project in 1970…

Looking NW toward the main radio site, with the historic building in the foreground.

volt/amp/watt/energy meters

Got another two of the inexpensive volt/amp/watt/energy meters from mfreelaa on eBay. These are pretty nice, especially for the $12 each including shipping.

I put two of them in series to see how well each tracked the other. There should be a very small drop in voltage for the second on in series as opposed to the first. That does appear to be the case.

The unit under test is pulling approximately 1-1/4 amps at 12 volts. Assuming these ammeters use 100 A/75 mV shunts (since the meters without built in shunts do the same and it’d be easier to keep them all the same) this would imply that the second meter should read about 0.001 volts lower than the first. However, the display precision is only 0.01 A so it’s not practical to see the difference with this small load.

After two hours now, both meters are showing 50 w-h, I’ll have to wait longer to see if they diverge from one another at all. The voltage (refreshed once per second) is generally within 0.02 volts, which is 0.15% agreement. The current reading is looser, maybe 0.2%. The power reading is quite close, but one would expect that the power reading comes from the multiplication of the v and i values. The energy reading is the time cumulative sum of all the power measurements.

Next project is to measure the efficiency of my new MPPT solar battery charger. Just need to have a sunny day!


Here it is the next morning and the DUT has now pulled a total of either 261 or 262 W-h, depending on the meter read. That’s still pretty good internal consistency between meters, well under 1% difference.

So, relatively speaking, these meters are pretty consistent in their performance. Perhaps one of these days I’ll set up a calibrated load to get a better handle on the absolute accuracy. But for now, just knowing that the meters are consistent allows me to do the solar MPPT charger testing.

And while I’m at it

Last week I had the pleasure to spend in far-south Chicagoland, where it started out 48 °F and raining and ended up 18 °F with black ice everywhere. Not immediately, but once the ice formed, it stayed in place the rest of my visit. Made for some dicey walking.

However, my buddies at the RR, like the post office, work rain or shine, ice or sleet, snow or sand, and were busy installing my hoped-for array of antennas on a homebrew rack up on the roof.

Little hard to see in the photos, but it’s basically a triangular array of 3 tripod mounts held down with a bunch of concrete blocks, then two-sided unistrut forming two vertically spaced equal equilateral triangles, upon which it’s easy to set vertical pipes to attach antennas.

Right now the lab I’m helping to build (in the building below) needs far better cellular connections for the industrial modems that we’re testing, so the antennas on the roof will solve a lot of our mysterious connectivity problems.

The lab also needs a solid GPS antenna on the roof – I have a rack-mounted 8-way GPS splitter inside and I’ll feed one antenna to multiple devices in the lab that need GPS.

The runs from the antennas on the roof to the rack are all 1/2″ superflex, and we’ve got grounded lightning protectors at the rack and shield grounds just before the coaxes penetrate the building. We’re also way lower than many better lightning targets all around us, so we’re probably as safe as we can be.

Next step is to head back there and start assembling some LMR240 jumper cables to run from the rack connections to the final resting places for the signals received.

It’s fun working on the railroad.

Update on the rooftop amp

Last time we visited the roof, the amp followed by the FM BCB notch filter was now in the die-cast enclosure, but not actually attached to anything.  Now it finally has a home, at least for now, on the tripod leg. It required a visit to Artie’s Ace Hardware in Phoenix at Tatum and Thunderbird, which until about 8 hours ago was unknown to me as a purveyor of a near infinite number of different kinds of metric fastener! Only 4 miles away, it’s a treasure to know that I can get an M4x8 mm pan head screw even late in the afternoon.

The metric hardware was required to install the steel mounting ears on the die-cast enclosure; those mounting ears accept the muffler clamps that hold the whole thing to the leg of the tripod. Later on this winter I’ll bend up some 0.032 Al sheet to act as a sun shield and remount the box on the north leg with the shield to keep it cooler during the summer. I still need to do something permanent about the power for the amp, it’s currently the solar power setup I made a couple weeks ago.

Left is input, right is output. Runs on any voltage up to about 32 vdc and down to about 7 vdc. The internal dc-dc converter keeps the amp supplied with an even 5.0 volts.

With this amp in place, my stack’o-scanners is just bangin’ along. I’ve got great reception, and no FM BCB interference. And, there’s space in the enclosure for a future Arduino or Raspberry Pi, as well as the necessary network connection.

Shocking new amplifier

Is finally built. I bought three of these a couple years ago from kuyaya520 on eBay and they’ve languished since then, heat-shrink protected and tie-wrapped in place, like for the truck’s half-deaf GRE PSR-600 scanner.

Finally put one in my new die-cast case that I got 10 of last month, and used a 82 ohm resistor to set the operating voltage to around 10 vdc when running off 13.8 vdc. According to the eBay page about the amp, its best gain and noise figure is around 9-10 vdc.

Checked out the gain, and it’s pert darn near what the vendor says it is. Don’t have a simple way to do noise figure. Need to get myself an ENR noise diode so I can do y-factor.

This amp will likely go into the truck to replace the tie-wrapped kludge… I’m starting to get reasonably good at assembling these things.

Next step on the rooftop LNA setup

This past weekend I finally started building the ultimate case to house the LNA and FM BCB filter for the rooftop multireceiver project.

Last night I did the final bit of wiring, installed a DC-DC buck converter to take +12 vdc and knock it down to 5.0 vdc.

Here’s some pics of the project.

The two separate die-cast enclosures are the LNA (lower) and the FM BCB notch filter (upper). There’s a LM2596 DC-DC converter in the lower left, and a weathertight Ethernet connection in the center-right wall. All external RF connectors are N. All internal connectors are TNC. All coax is RG316 double-shielded. I used an Ethernet connection to get power to the box and to allow the future addition of either an Arduino or an Raspberry Pi for telemetry purposes.

The overall enclosure with installed components. Got this particular enclosure for about $22 delivered – someone in Santa Maria CA didn’t want it. Was missing the base plate upon which I mounted all the components – fortunately, I had a piece of Al in the garage that was a near-perfect fit! Would have cost nearly $70 new.

The left N connector is the antenna input, the right N is the assembly output to the shack. The Ethernet connector is for future expansion and dc power.

Installed on the roof temporarily (will be mounted on the tripod to right ultimately) with power supplied by batteries in the Tupperware container.

The batteries (Eneloop AA x 10) are charged with a newly modified solar panel install. Again, over the weekend I cut some Al extrusions to replace the old way I’d attached a single 5 w solar panel, now it supports two 5 w panels for a total of 10 w. This almost guarantees sufficient charge for long winter nights.

In addition, the box mounted on the tripod already had a PoE Ethernet connection from the main rooftop unit. I use that 12.6 volt PoE  through a single 1N4001 rectifier to source power to the LNA box when the solar panels can’t provide enough charge to keep the batteries up. I want to add some telemetry (through a future Arduino or similar on the roof) to measure voltages, temperatures, etc.


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