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Radio Astronomy/SETI Argus


Dish Looking East

Dish Looking East

RADIO ASTRONOMY/SETI: The movie “Contact” sparked an interest I seemed to have had way down inside.   Using the Internet, I searched for more information into actually trying to listen for signs of intelligent life beyond what we consider our home, the Earth, Solar System and our own Galaxy.   In 1997 I became a member of the SETI League. and the result was that I built my own Radio Astronomy / SETI Argus research station. Here are some pictures of QSLs I got from space communications.

It all began with me needing a dish. I was living in Claremore OK at the time. And the college I was working for, had a UHF TV station. I noticed that they had some sort of dish about mid way up on their television transmitter tower. After looking at it with a pair of  high powered binoculars, I noticed it didn’t seem to be hooked up to anything, just bolted up there about eighty feet in the air. I talked to the station manager about the idea for taking it down. He said that I couldn’t do it because it was a commercial tower and the only ones that could go up there would be commercial tower climbers. RATS!

Dish Birdbath Mode

Dish in Birdbath mode

He saw that I really wanted a dish and told me that he had an idea for me to get another one other than the one high up on that TV tower.


The dish is a twelve foot cable front end receive only (RO) unit I got from a guy in Claremore that used to install commercial cable TV systems. This particular dish was in his backyard and he told me that I could have it if I would remove it from his yard. I remember, at that time, it was cold as a witches whatever. But, after spending almost two full days with tools in hand, I got a friend to haul all of it away to my back yard. It was MINE! All mine!

I proceeded to clean each part as much as I could in the evenings after work. I wire brushed and sanded the fiberglass edges of each dish section. I soaked each nut and bolt and other metal parts in metal cleaning solution and wire brushed them as well. I painted the base, pivot and feed horn tower.

I then began building the base mounting substructure. This consisted of three 3/4 inch three foot bars of all-thread and tow steel plates with the exact same bolt pattern as the base. This would be what gets concreted in place.

By then it was March and I began the project of erecting the dish. I trenched the yard down two feet and ran 3/4″ conduit 40 feet to the dish location. I then dug a hole 3 foot square and 5 feet down. I dug a 2 foot deep six inch hole with my post hole diggers in the middle and drove a steel fence post three feet into that hole leaving about a foot extended past the top of the 6″ hole. This was what I called “the tap root.” I then built a little frame out of wood to position the substructure in the center of the hole. Then came the concrete. I bought 60 bags of premix and a bunch of rebar from the local hardware store. I borrowed a portable mixer from a buddy and began…It was a nice sunny day and I remember it was cool, not cold. At the end of the day I had a nice concrete base curing in the back yard, and a hell of a sun burn on my head, ears, nose and any skin that was exposed. Let me tell you that when you are working that hard, long sleeves came off and a nice light short sleeve T-shirt replaces helps keep one cool. BEET RED I was.

To make a log story short. The dish in Claremore never got wired up. I was beginning to get a bit antsy. I kept talking about a little raise in salary but nothing came. I ended up leaving the college for another job in Tulsa to the tune of adding $18,000 more to my annual salary. So down came everything. The radio tower, dish, everything came down and moved to their new home in Tulsa. The setup for the dish went pretty much exactly as it did in Claremore except I made the pad about an inch higher so it would be easier to weed eat.

In Tulsa after the concrete set, I quickly mounted the base. I bought some really nice electrical boxes to hold all the wiring and relays and stuff and ran all the cables through the ground mounted conduit. Another thing I did differently from Claremore was to put in one inch pipe instead of the 3/4 inch. Excellent decision! For quite a while, over a month or so after that, I did nothing more to the dish.

Me in hole

Me digging it

Looking at the hole

Looking at the hole

Dish Tap Root

Dish “tap root”

Spreading the dirt from hole

Spreading it out

I don’t know why I’m making such a face, probably because nobody’s helping me except for the camera man, which is, by the way, a tripod.
Elevation Motor

Elevation Motor

Azimuth Motor

Azimuth Motor

Before I got the actually dish mounted one of my buddies I’ve known for a long time came up with an excellent design for azimuth control of the dish, leaving the existing positioner  to function as elevation control with a slight modification of the assembly. He took the base over to his shop and created a big sprocket gear unit and a bracket to hold a 24 volt DC motor. He then setup a chain drive to the sprocket and welded all the parts in place. He inserted a zert fitting into the sprocket and used a special grease. He said the entire assembly was using the grease as a bearing since the unit wasn’t going to move very fast. I had my doubts about this, but during the five years it was up, he proved my doubts were in error.

Motor Control Relays

Motor Control Relays

All the dish electrics were housed in two weather resistant electric boxes mounted to the stem of the base. Relays were fitted onto perfboard and mounted into one of the boxes. The bottom box housed the terminal strips and motor control relays, and the top, smaller box was for the 1.4 GHz calibrated noise source for calibrating and testing the dish. All in all there were two different feed horn configurations for the dish. The first was a single monopole 1.4 GHz and the second was a dual monopole arrangement that along with two matched low noise amps and a hybrid could be used as a single, horizontal and/or vertical or either right or left hand circular depending on how the arrangement was switched.  Pretty freaking cool, huh?

 

Dual Monopole Feed Horn Assembly – Designed By Tommy Henderson WB5AGO

Dual Monopole Feed Horn Top

Dual Monopole Feed Horn From Top

Dual Monopole Feed Horn 1

Dual Monopole Feed Horn Looking in from bottom

Dual Monopole Feed Horn 2

Dual Monopole Feed Horn Looking Inside

Dual Monopole Feed Horn Parts 1

Dual Monopole Feed Horn Parts

Matched Low Noise Preamps

Matched Low Noise Preamps

Low noise preamp housing

Low noise preamp housing with preamps

Low noise preamp housing 2

Low noise preamp housing with preamps

Feed horn - Notice the antenna for noise source beneath it

Feed horn – Notice the antenna for noise source beneath it


 

The dish is ready and now we need something to connect it to. I purchased a used Icom IC R7000 receiver with all the intention of  using it for SETI and Radio Astronomy, but when I tried the 1 GHz switch, the radio just emits white noise and any signal that should be there is not. So, I had to do something.

Console Ultra-Spectra Cyber

Ultra-Spectra Cyber gray unit in Console

A little more research results in finding the perfect receiver for the job. I found the Radio Astronomy Supplies (RAS) web site and in their catalog was the UltraCyber 1420 MHz Receiver. Next thing I knew, it was sitting on my kitchen table. I opened it and read everything that came with it. I downloaded the software, installed it and hooked up the receiver. FIRST LIGHT in 30 minutes. The receiver and software allows for turning on and off the calibrated noise source out at the dish, so when I saw the changes in the output on the graph, I knew the receiver was indeed hearing it. WOW!

So I began to play with the new toy and after 6-8 months, I emailed Jeff at RAS and he told me for a small fee, I could upgrade my Ultra Cyber to a full force Spectra Cyber system. Next thing I know, it’s on its way to RAS for a Spectra Cyber upgrade.

My Spectra Cyber came back and I noticed it had both the ultra Cyber and the Spectra Cyber labels on it. WOW! I really liked that. What a great touch to the front of the unit. One cool thing also, is that RAS included a 70MHz jumper in the back so I could add a scope or anything I wanted that would take the output. VERY COOL INDEED.

NOTE: Since the move to Oklahoma City, the SETI Argus station has been disassembled. The dish and Az/El motors were donated to the Tulsa Community College. But the feed horn and receiver are safely in a box in the attic awaiting further instructions. Presently there is no date set to rebuild the station, as I now live in a Home Owners Association (HOA) with a covenant preventing the erection of a dish.