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—Details—
Peak: W5N/BA-005 – 7284 [Socorro Peak]
Location: Socorro, NM, DM64mb
Time: 20 July 2013, 1700 UTC
Bands: anything I can manage. Likely 20m and up, and 2m
Mode: SSB preferred, but I want to try to muddle through some CW. I’ve never done CW without a computer (shame on me) so PSE QRS!

On 20 July, I plan to activate a nearby mountain for SOTA. This isn’t any regular mountain – the some parts of the road up to the peak is owned by EMRTC, or, simply speaking, its a bombing range. Therefore access is permit-only and this plan is tentative at the moment [edit — It’s a go!!]. However, at last night’s Socorro ham club meeting, I met a guy willing to be my escort, so I don’t get blown up, and to make sure I don’t steal anything, I suppose.

Map of the area and the Summit. [http://sotamaps.wsstvc.org/]

BA-005 is known as 7284 on the SOTA map, but the peak is commonly referred to as M-Mountain or Socorro Peak. A nearby peak which has a large, limestone M on it isn’t included in the database because it’s too near the taller peak.They only differ in elevation by about 60 feet.

This shorter peak is the home of the famous Elfego Baca Golf Shoot, where participants tee off at about 1500ft above and 2 miles awaythe hole. I think it’s a par 36 😀

Instead of golf, we’re going to shoot for some QSOs.

I’ll be using my new fangled End Fed Half Wave coupler and some conveniently placed towers. If those don’t work, then I’ll revert to some hamsticks. Stay tuned for more on the antenna project, and the summaryof the activation!

Our station was active for almost 24 hours, minus a lull at about 1:10 am Sunday morning. Our backup arrived at around 2 am, which included Brian (N5ZGT, Rocky Mtn Division Director), who just got back from a Turks and Caicos island vacation (or DXPedition, you might say), and Scott (N5SQR) who worked PSK and SSB.

Setup and Operation 

Beam

TA-33 with the 80m windom in the background

Dipoles

On my first shot, I got over this tree and the line sat perfectly on the brown number post.

The perfect shot.

Old Glory on our 80/40 trap dipole

RPi camera

Operation

We were 2A, so we had 2 stations on the air, all supported by batteries. We operated SSB, CW and PSK31.

Scott, N5SQR working SSB

No field day station is without its problems. We were lucky to only have minor issues, like the logs not syncing or the digital station computer interface not working. These were easily and promptly fixed. Everything else (except for the band conditions) was perfect.

Our ops came from all areas of the hobby. Brian, for example, just got back from Turks & Caicos, and worked hordes of stations from VP5-land, while Seth never worked a contest before being a technician.

Brian and Seth teaming up to send Radiograms for bonus points

Seth taking names and gettign mults on the voice station

Seth quickly caught the Field Day bug and worked the 12-1am shift by storm, and eventually took both working and logging on the voice station on solo.

It was very cool to see him warm up to the air and get excited to work stations. It reminds me of my first Field Day, where I was thrown into the action and started racking up QSOs as fast as any other operator after only having a few hours to figure it out.

A visitation by the local sheriff

  Satellites

The Arrow LEO-SAT yagi and other antennas in the background

Sat Station Setup — FT-817 for RX and an 897 for TX

My job at W5MPZ was to bring a satellite QSO to the log for an extra 100 points. Unfortunately, this didn’t happen.

I had several attempts at SO-51 (the only FM satellite), VO-52, FO-29 and the zombie AO-7 (all SSB/CW transponders). I had most luck with the SSB satellites but had problems in being able to hear myself.

To work the SSB satellites (all but SO-51) you need to know where your signal ends up after it gets translated to the other band. For example, FO-29’s uplink band is 145.8-145.9 MHz, while the downlink is 435.9-436.0 MHz. One would think the 100 kHz passband would be linearly related, e.g. I transmit on 145.85, and hear myself on 435.95, but this isn’t the case. The doppler effect causes the frequency to differ by up to 500 kHz on UHF, so you need a way of calculating doppler, or simply finding yourself.

My technique was to spin a carrier through the passband until I heard it on the downlink, and switch to SSB to call CQ and tune into myself. Upon the switch, I lost myself.

I figured out the solution on the last pass of the weekend. The FT-897 has a feature in SSB mode that allows you to send CW at your tone frequency. So if I’m on 145.000 and have a 700 HZ CW pitch, it would send it at 145.000.70 MHz. Therefore, if you were tuned into 145 MHz on another rig, you’d hear that same pitch. All I had to do was zerobeat on the flipped bandpass, and call away. I finally heard myself repeated by the satellite, but didn’t have any replies within the last 5 minutes of the pass.

It was worth the effort (and in hindsight I should have just worked the ISS’s message system via packet)!

Summary

The underlying point of Field Day (aside from preparedness) is to have fun. W5MPZ did exactly that. Our support team of family members kept us well fed, watered, sheltered, and our batteries charged. One could not ask for a better place to set up and operate from, and the weather (despite being cold in the mornings) was amazing – not having wind and the 100°F temperatures to contend with was a huge relief.

I’m not sure of the final QSO count or score, but we only missed a few sections in Canada – NT, MAR, and ONN I believe — like we expected. Field Day isn’t a contest, so the score isn’t important to me or any of the operators aside from personal club goals and whatnot, so that wasn’t a worry. What matters is the coming together of like-minded people to getaway from the daily grind, have a ton of fun, share stories, and work stations.

It’s always been a dream of mine to put on glasses that allow you to see only waves of RF emitting, reflecting and illuminating the world around you…this would make my job so much easier too!

Well, there just so happens to be such a thing that allows you to see RF…it only requries about 3 acres and 250 antenna elements, a supercomputer and a fast internet connection.

The LWA near the VLA

The Long Wavelength Array is a seemingly random assortment of crossed dipole pairs with a frequency response of 10-88 MHz. Every antenna is separetly fed into a giant computer that correlates and beamforms the array into a giant RF eye looking at the sky.

LWA Dipole Detail with the VLA in the background

And by eye I really mean it sees the RF world above it in real time:

Above is a real time view of the sky above the LWA (hit F5 to refresh, I dare ya!). During the day you can see the sun and several radio sources like Cas A, Tau A, and Cyg A which are galaxies, pulsars, and other nebulae of ridiculously “loud” RF emitters. Also, at the top and top left, you can see RFI from the VLA site, which is one of the things we’re working to alleviate.

Another cool thing it can do is plot spectrum over the whole day:

This shows the intensity at all frequencies between 10 and 90 MHz over a 24 hour period starting at 17:00 PST 11 July 2012. You can watch the nighttime MUF drop between 00:00 and 06:00 PST, and surge again at sunrise. Other strange and interesting patterns exist as well — check out the index at http://lwalab.phys.unm.edu/lwatv/ovro and see what you can find.

Ckeck out their website at www.phys.unm.edu/~lwa/lwatv.html and read technical information about the LWA here, and an even more technical dissertation here.

73!

New Mexico is dry. I was floored when it rained three days ago. But for 11 months out of the year, the air is dry, the sun is bright, the clouds are facetious, and everything’s on fire. 

Smoke plume from the 30,000 acre Silver fire

Smoke fills the horizon

 Such is life in NM. The 10% humidity caused me some pain and suffering for a while, but I seemed to got used to it. I used a lot of normal lotion, which wasn’t the best idea for being out in the sun so much.

Currently, a large chunk of the Gila mountain range is on fire, but thankfully few people live in the area. The Silver fire (named because its near Silver City, NM) is currently at 32,000 acres, making it the biggest fire in the US. From atop a VLA dish, you can see the smoke plume and the long trail of smoke being carried by 30-40 mph surface winds. It’s quite dark in Truth or Consequences.

Aside from the fire, the plains of central New Mexico have a variety of weather, typically involving some kind of dust and lots of wind:

Dust carried aloft by 40 mph winds

We even have tornadoes of dust! (Seriously, some of them are big enough to cause damage):

A particularly strong dust devil with a well defined center column

Then, all of a sudden, it storms:

A snowstorm to the north…it’s a rare event to see precip actually get to the ground.

Above, you see it’s snowing. Snowstorms in the southwest isn’t a myth after all! Just last year, a snowstorm dumped 2′ of snow on Socorro, NM.

Typically though, the air is so dry that any precipitation just evaporates before it hits the ground. This phenomena is called virga, and is the sole reason why the clouds are so facetious. What does hit the ground are tendrils of lightning, graupel — basically mini snowballs from the sky — and hail.

A tendril of lightning betwixt two VLA dishes

In 2004, hail fell with a vengeance:

So its dry, its dusty, windy and usually boring (minus the bits of hail, getting caught in a haboob, and waking up to lightning barrages)…but now is the season for rain. And we’re in dire need. NM has been in a 10 year drout, and wells are drying up like int he community of Magdalena, NM, just east of the VLA.

Locals believe that July 4 is the day which marks the start of the monsoon season…don’t take monsoon to seriously though, it’s not like the monsoons of India and Asia. They may dump 2″ of rain, but that gets sucked up so quickly by the dry, absorbent dust and flora of the mountain ranges that it was like it never happened the next day.

We’ll see what the skies bring.

A few weeks ago, the IPG got some curious email from some ABQ-ians asking if they could play Ingress at the VLA to capture some GPS-based portals. If you’ve never heard of Ingress, think of it as geocaching with a Virtual Reality spin. Check out their website here.

Ingress is played on smart devices, which require data connections to operate. These data connections are fine and dandy unless you’re at the world’s greatest radio observatory; here they aren’t so dandy.

RF-EMS

Below is a screencap of our RF-EMS (Radio Frequency-Environmental Monitoring System) which captured two WiFi access points (the darker blotches) from an RV containing a Verizon 4G hotspot and another router for something else.

Your VLA on WIFI

In the last blog I described the 10′ dish for pinpointing RFI. We also have a (usually) 24/7 monitor that uses some pretty nifty antennas and preamps on a 50′ tower, sending it to an HP 70000 Spectrum Analyzer in a RF-shielded room from which we can record and upload plots like the one above, every day for the past 5+ years. 

RF-EMS Tower and Bunker

The biggest downfall is adequate locating of interfering transmitters. Currently, I’m designing a method which will allow the IPG to quickly and accurately pinpoint people with any kind of transmitter, be it a cell phone, hotspot, or vehicle keyfob (if we wanted to locate such things). My idea is based on multilateriation, which uses multiple receivers around the site which compare arrival times to calculate a four dimensional location. Keeping the bill of materials as low as possible, simplicity, ease-of-use and network integration (without causing RFI itself) a prime focus.

It may be overkill, but it gives me something to do in the free time.

Other Doin’s: Testing out and Debugging the 74 MHz System

When I’m not having free time, this is what I’m doing. A new feature of the Expanded-VLA is observations on the 4 meter band. The current system in place uses these simple crossed dipoles hoisted a few meters below the sub-reflector.

The cross dipoles connect to our receiver, which hooks up to the rack that magically digitizes the signal and turns it into pulses of light which the correlator feeds upon.

One of the problems we face are things broken that don’t have to do with our antennas and receivers. For example, the first test we do to examine the receivers performance is a band pass plot. Often times, we see something like this:

A bad bandpass plot caused by a faulty relay in the T301.

This is ugly! What we want to see is this:

A beautiful bandpass! You can see 4 band on the left, and P-band in the middle with RFI spikes all over.

First we go digging in the LO-IF and FE racks for a place to stick a spectrum analyzer to…

And from that we figure its’ this T301 which does the first IF up-conversion from 0-1GHz to 1-2GHz.

We get a new one, stick it in, turn it on and voila, it’s alive!

Like I mentioned, today Paul Harden, da boss, and I installed two more low-band receivers today, but with only a 50% success rate.

The receiver is  dual banded for 74MHz/350MHz and is housed in a big and heavy 8″x12″ metal box. for thermal stability. We call them LBRs or 4/P receivers — 4 band is 58-80MHz (eg 4 meter wavelength) and P-band is 325-420 MHz or so. P comes from it’s old military designation, like L, S, C, X, Ka, K, Ku, radar bands, etc.

She’s mounted on a sturdy mount inside the “barrel” also known as the Focus Rotation Module, or simply the apex. It’s also my second home. Inside the barrel is a central square steel through which the 4-band antenna and receiver output cables go through. The receiver mounts near the bottom of the apex, and plugs in to 8 different cables – two pairs of Heliax for the 4/p band crossed dipoles, one Heliax pair for the output, a power cable, and a calibration signal cable.

Each antenna input requires two pair because of the dipole design — they’re orthogonal crossed dipoles that are fed into the receiver as two linear polarizations. Some magic happens in the LO-IF rack that either sends them as a linear polarization to the correlator (mainly for ionospheric observations) or combines them in quadrature to provide left- and right-circular polarization for observations outside our own solar system.
The first installation went smoothly — we removed a malfunctioning receiver from antenna 18 and replaced it with a fresh one — it’s pretty much plug and play. Somewhere through, we lost a two-way radio. No idea where it went. I think it always existed in some kind of quantum state, and now it’s hiding.

The second was troublesome. Each output, left and right polarization (or X and Y) should show clearly the band passes of each band through a spectrum analyzer. What we saw was spikes caused by the 74MHz *something* oscillating like a runaway Hartley. (that was a pretty poor play on words)

So we hit it a few times, jiggled the cables, and poof, it was back to normal! We came back down to the vertex room to find it again went nuts. So we went back up, wiggled some more, and took the SA with us. Now the X side was gone! We took the cover off and poked around, but it was dead. Methinks the oscillation was strong enough to saturate an LNA, bust a cap or diode or two, and kill X.

Paul’s gonna play with it tomorrow, and we’ll see if we can make our pseudo-deadline of getting everything working by Tuesday night. Lots of pressure from the higher ups.

Tonight, I’mma gon’ write a blurb about the SDR demonstration at the ARRL Youth Lounge at Dayton for Ward Silver, N0AX, upvote and argue things on reddit, and buy some wire and ladder line for field day. Need to make a 9:1 balun by then too.

View of South baldy and the Magdalena Ridge from the bus ride home

With midnight inspiration comes morning desperation. For sleep. Heh heh.

Welcome to the new blog of N0SSC — ARRL Youth Editor, EE degree seeker, Very Large Array intern, and among other things, a radio amateur. Ideas have been flowing from my mind into thin air, so I have done up this blog to start to capture them.

I’m a zero in five land. My call sign – N0SSC, shows that I am from zero-land: the ham radio call district that makes up most of the midwest. Due to my internship, i’ve been displaced to New Mexico, which is in the fifth call district – 5 land.

So, this blog will focus on my ham radio activities while in New Mexico, as well as my internship at the Very Large Array. I have a lot of fun stories to share!

Stay tuned for more! For now, follow me on your favorite social networking site — just google N0SSC and you’ll find me.