Week Two
07.09.2018
What is a Horn Telescope?
Part of Kevin' Bandura's goal for this program is to develop a low cost radio telescope (<$100) that could be easily constructed by, and for, high school teachers to use with their students. One of the strongest sources of radio waves coming from space is the radiation of 21-cm wavelength radio waves generated by cold neutral hydrogen from the plane of our Milky Way Galaxy.
Neutral Hydrogen Map of Milky Way Galaxy
The following image is a screen capture from the Wikipedia article on Hydrogen Lines. It seems to contain the basic information about what the 21-cm Hydrogen line can tell us about our own galaxy...
The Horn
An optical telescope is curved such to reflect the visible light into a sharp image that can be seen. The Horn is quite different in that it is designed to reflect the radio waves into the resonance can chamber. The antenna is placed at an anti-node point of the standing wave we wish to look at (the 21-cm), thus (21 cm) / 4 = 5.5 cm. Here is a quick diagram to explain the nature of the Horn.
There won't be a sharp image, but there will be a stronger signal in the general direction it is pointing.
Our Week Two--No Lecture Classes (just stating the facts)
The main 2 goals were for us to make a horn telescope for each of us (6), and to have the lovely experience of soldering the 40 or so tiny components of the Low Noise Amplifier on the circuit board. Since we had the 4th of July off (Wed), we worked 4 days at creating the 6 scopes. With John and Howard here last year, and Dan seeing lots of possible improvements, there was a fair amount of brainstorming ways to make it more portable. Eventually, we got into an assembly line mentality and people fell into niches that needed to be filled to get the job done. We spent the time in a nice tech lab that would make my fellow tech teachers drool.
The two major improvements over last year's design was:
1) To make notched 2x4 base pieces instead of bolting them together. This allowed for quick assembly and disassembly.
2) To make a "horn holder". Basically a cage slightly bigger than the can for the can/hold assembly to slide in. Pieces of styrofoam are used to wedge it tightly in place. Last year's design had it taped in place. Again, quicker assembly and disassembly.
An aluminum screen horn design is being worked on to allow wind to blow through horn walls to reduce shaking or tipping...Stay tuned! (That's a radio astronomer's joke.)
Getting ready to build scopes in the Shop
Getting Jinky with it
Lots of Conducting Aluminum Tape
How Much Wood...
Trying a new notch design
Cutting some wood
Let's Make Some Horns
How many science teachers does it take to cut a metal can
Find Your Inner Balance
Putting the A in STEAM
Take us to your Leader
And the rent is only $400 a month!
Horn Head from ...Florida
Designer Horn Wear...Wait a minute...Where's my other foot?!
Friday afternoon...time for the weekend...all parts ready, but no fully assembled scopes. Wait for Monday!
