"Cloudsonian" – DIRECTV Solar (And Other) Itty Bitty Radio Telescope Setup For Daytime Fun – Part 1: Cheap PoC

Above (and we didn't do this): The Very Large Array antennas dip in formation to observe a target in the southwest sky. Radio telescopes can observe day or night. From https://public.nrao.edu/gallery/the-backs-of-the-vla-dishes/

When we first bought the house, the DIRECTV dish was screwed in tight on the northwest side and we had no intention of ever doing anything with it because everything we want (WXXI) is pumped direct into our digital antenna. That said, you can't do amateur astronomy and own a dish without at some point wondering if you could do some kind of observing with it – which eventually led me to Mike Brown's "Summer project: Build a radio telescope at home" page on making a solar scope on the super-cheap. A long time ago. "I gotta try that," as the saying goes.

The issue was forced this year by my eldest remarking on how the dish wasn't doing any good in the basement by itself. Good point. It's been seven years, but it is an outdoor dish designed for whatever weather conditions Western NY can throw at it, so I decided it was worth a little bit of money to see what might come of trying to, at the least, pick up the Sun with it.

And it works(!), even it we're a loooong ways away from the movie Contact. I present to you our proof-of-concept house "Cloudsonian" – good enough to find the Sun, geosynchronous satellites providing signal, and other stuff we've not yet identified. Also nearly as much fun as a four-year-old can handle for a good 30 minutes.

And, of course, there is nothing new about this – the Itty Bitty Radio Telescope has lots of precedent (and links) and lots of examples (and links). Some relevant links (and links) below:

  1. https://nightsky.jpl.nasa.gov/docs/ibtmanual2.pdf
  2. https://www.gb.nrao.edu/epo/ibt.shtml
  3. https://www.radio-astronomy.org/store/projects/ibt
  4. http://www.stargazing.net/David/radio/itty_bitty_radio_telescope.html
  5. http://arrl.org/files/file/ETP/Radio%20Telescope.pdf
  6. https://www.aoc.nrao.edu/epo/teachers/ittybitty/procedure.html
  7. https://www.opensourceradiotelescopes.org/itty-bitty-radio-telescope/
  8. Whatever else your web search for "Itty Bitty Radio Telescope" might come up with

If you just wanted to try something, had some money lying around, but didn't want to go into any real technical detail, the below and some aim will get you buzzing.

Parts List

  1. The Complete Dish (for us, with a LNB SL5S4NR2-02) – honest to goodness, there was another one out in the trash at a neighbor's house last year and I didn't think to go out late at night and take it. You might find one cheap on craigslist, might just see one on the street, who knows. Parts are also all over ebay. The range for this sized dish is 12.2 to 12.8 (OK, 12.7) GHz, or the entire Ku band of the EM spectrum. You'll find this out if you do broad searches for "other uses for DIRECTV dishes," where some of the most interesting uses are for outdoor cooking.
  2. ($57) Tripod – we went very cheap on first pass, using PVC I had lying around. We had so much fun that I eventually sprung for a proper tripod to make life (and aiming) a bit easier – 3ft Heavy Duty Tripod Mount for Starlink, Antenna, DIRECTV, Ubiquiti (includes 1.66" by 2" diameter Mast) – https://www.amazon.com/gp/product/B0B2213CV7
  3. ($13) Power Supply – you can do this by soldering some connectors together to get enough 9V batteries to do what you need, but, for $14, you can just buy something you don't have to fiddle with – AT&T (Formerly DIRECTV) 21 Volt Power Inserter for All DIRECTV SWM LNBs (PI21) – https://www.amazon.com/gp/product/B005AME7Y8
  4. Satellite Finder – bought two because the first one (orange) didn't work on battery alone, then the second one (blue) ended up being touchy when plugged in. Orange + Power Supply = audible detection.
  5. ($4) Coax Cable – if you don't have a spare – Monoprice RG6 Quad Shield CL2 Coaxial Cable with F Type Connector – 18AWG, 75 Ohm, 6 Feet, Black – https://www.amazon.com/gp/product/B003L1AG72?th=1
Theodore (4), amateur radio astronomer

We had it out for an hour the first time, fighting with the PVC stand to point the dish at the Sun, then at the rough position we knew the DIRECTV satellite to be, then at various other locations just looking for legitimate changes in signal.

The Thrill Is Not (Entirely) Gone…

It comes out intermittently at this point. After the March setup, we used it during the April 8th Total Solar Eclipse this year. Given the ridiculous cloud cover we had in the Rochester area that entire afternoon, our use of the dish to find the exact location of the Sun and point it out to backyard attendees was entirely reasonable.

Poorly framed, poorly focused, but three generations and the rig on the tripod on April 8th.

I'd be remiss in not mentioning the several relevant pages put together by Martin Pepe on the ASRAS website for those looking for some more background (and others in the area who have done the same or much, much better).

A very simple Round 1 is in the bag and we'll see what else we decide to do with the dish or something more involved as another observatory project. Stay tuned (no pun intended).

Free Astronomy Magazine – And Aurora! – July-August 2024 Issue Available For Reading And Download

Above: The Sun, putting on another show the morning after (11 May 2024) from downtown Rochester.

The most recent issue of Free Astronomy Magazine (July-August 2024) is available for your reading and downloading pleasure in English, Italian, Spanish, French, and Arabic at www.astropublishing.com (and facebook).

Browser-readable version (and PDF download): www.astropublishing.com/4FAM2024/

The amazing aurora from May 10/11 of this year (didn't you hear? earthsky.org/earth/auroras-last-night-extreme-solar-storm-wow-millions-may-10-11-12-2024/) was perfectly timed to coax an informative article for this issue about when and how often the Sun might be far less benign. Since the solar events of 1859, we've gone even farther down some "War Of The Worlds"-esque path, where our technology has become simultaneously more complex (computation) yet more fragile (one good solar storm = kaput). Whereas the Carrington Event lit some telegraph lines and made for some great press the days and weeks after, a similar (or worse) event might risk knocking out every satellite we have in orbit and a whole lot of transformers on the ground, setting us back decades and sending us back as far as our own natures might permit.

With that said, I'm very pleased that Michele chose to replace one of his much better aurora pics from the original draft with one that I took (that I only sent along to show him that we had a display here as well).

That story – The Mrs. and I snuck out after the kids were asleep on May 10th in hopes of finding a quiet clearing along the southern edge of Lake Ontario. Try as we might, every festival that could have been going on was going on. 45 minutes of driving later, we head back to the house having not seen much of anything on the road anyway. I park and go to the deck for one random look and, good heavens, aurora! We're minutes from major retailers, lit parking lots, neighbors who have complicated my observing attempts for years, and the show was amazing. Grabbed the camera and tripod, set to long exposure, and just hung out for another hour. Was, by far, the best show I've ever seen the Sun put on. Click either below for a larger view.

Dazed and tired from the night before, we're making our morning rounds on the 11th when the Sun put on another impressive show from the comfort of our sunroof – in this case a gorgeous halo.

Morning solar halo, with random bird for unusable scale.

Made up, a bit, for missing the total solar eclipse around here.