A lecture on Radio Astronomy The amateur can t really afford

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A lecture on Radio Astronomy

• The amateur cant really afford a large enough
  dish to make Radio Astronomy a good hobby

Joe Perry August 2009 Wb6dco
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What do we need to really receive noise from
space atomic atoms that vibrate
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Moon Bounce EME
To quantify the path losses the distances and
reflection efficiency of the Moon are required.
The Moon is around 385 000 kilometers distant
from the Earth. The surface of the Moon is also
reflects only about 6 of the radio signal power
that reaches it. Added to the path loss for the
signal travelling to and from the Moon, the
overall path loss is around 251 dB on 144 MHz and
270 dB on 1296 MHz.
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The Dish, big and ugly
30 Dish is way too small
The Home big ugly dish (BUD) comes in sizes from
3 feet to about 16 feet.
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The largest BUDs are usable for Radio Astronomy
or better EME Moon Bounce
Parks 64 Meter Dish is really what you need to
get those faint signals
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Radio Wavelengths of Interest in Astronomy
Significant Radio Astronomy Frequencies The
following radio astronomy frequency bands were
recognized at the 1979 World Administrative Radio
Conference. Many are shared segments, not
specifically protected from interference by other
authorized users, but are nevertheless generally
accepted spectral regions for radio astronomical
observation. The lower two segments are generally
used for solar and Jupiter observations the 73,
150 and 406 MHz segments are quite popular for
pulsar detection, and the 1400 MHz band is used
for hydrogen line measurements. 13.36 - 13.41
MHz 25.55 - 25.67 MHz 73.00 - 74.60 MHz 150.05
- 153.00 MHz 406.10 - 410.00 MHz 1400.0 -
1427.0 MHz
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Frequencies for Atomic Atoms
Substance Rest Frequency Protected Frequencies
Deuterium (DI)327.3840 MHz327.0 - 327.7 MHz
Hydrogen (HI)1420.406 MHz1370.0 - 1427.0
MHz Hydroxyl radical (OH)1612.231 MHz1606.8 -
1613.8 MHz3),4) Hydroxyl radical Water vapour
(H2O) 380.197 GHz 379.81 - 380.58 GHz Carbon
monoxide (C18O) 439.088 GHz438.64 - 439.53 GHz
Carbon monoxide (13CO) 440.765 GHz440.32 -
441.21 GHz Hydrogen cyanide (HCN)797.433 GHz
796.64 - 789.23 GHz Formylium (HCO) 802.653 GHz
801.85 - 803.85 GHz Carbon monoxide (CO) 806.652
GHz805.85 - 807.46 GHz Carbon (CI) 809.350 GHz
808.54 - 810.16 GHz
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Some Frequencies will be too noisy to record

• Ham Band 1.2 to 1.3 Ghz (23 cm)
• The all time best is the Hydrogen Line
• Hydrogen (HI)1420.406 MHz1370.0 - 1427.0 MHz
• Most BUD dishes can work easily in the 1 to 5 Ghz
  bands with the proper LNA or LNB receiver diode.
• 406-420 Mhz and 608-614 Mhz UHF TV old channel
  areas also can be used in Radio Astronomy.

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General Setup for your Dish
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The Receiver FM box tunes 1.420 to 1.665 Ghz
Pricey 1500
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But you still need more parts. You need the dish
horn cover and a receiver LNA
Feed Horn Cover for the LNA to help keep noise
out 130
A low noise amplifier diode LNA 130
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More Parts yet to come.
I dont think you will be home brewing this low
noise receiver stuff. 575 for the converter
Here is a low noise amplifier 150
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Other test parts

• Calibrated Noise source to test your equipment..
  Whos noise is it! 95

A narrow band pass filter will help also 130
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Books on Radio Astronomy

• "AMATEUR RADIO ASTRONOMY"
• SYSTEMS, PROCEDURES AND PROJECTS"
• by Jeffrey M. Lichtman.
• This NEW CD is the first all subject, all
  frequency range compilation of amateur radio
  astronomyinformation. A timely collection of
  amateur radio astronomy projects from amateur
  radio astronomersand professionals. In addition,
  radio astronomy basics, antennas, construction
  techniques and signalprocessing techniques are
  covered.
• Over 200 virtual Pages.
• This book is a MUST for your radio astronomy
  library.
• PRICE 17.00 5.00 Shipping / 20.00
  Foreign (Air)

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Now you need to record all this noise from space

• You need a good A/D recorder device for you
  computer.
• Then you need good software to run FFTs to
  analyze the data.

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Resolution in the SKY

• This will depend on the dish diameter.
• You would like the smallest width front lobe.
• You will need to correlate the pointing of the
  DISH to the Optical Sky map.
• Most just let the sky drift by and record the
  signal changes.

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Dish sizes and Efficiency by N1BWT in 1997
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Dishes suffer from many problems.

• The surface of the dish needs to be near perfect
  so that the signals from all over the dish do not
  null each other out.
• The dish suffers from spillover. This requires a
  good shadow Horn to reject off axis signals.
• You local EMI environment from power lines,
  Earth, Grounds, AM, FM, SSB, microwaves will all
  interfere.

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Use UR BUD dish for EME off the moon

• Well when you get tired receiving noise all the
  time you can buy or make a 1296 Mhz ( 23cm)
  transmitter module.

EME 11 meter dish By OE5JFL
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You have to have lots of power and room for all
the support equipment. He uses 1 watt!
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EME by K6PF

• Moon Bounce with 2m Yagi
• Antenna KLM 13LBA or larger
• Az-El motor system to track the moon
• Yaesu FT-726R
• Time wave DSP-59
• TE Systems brick preamp 180 watts
• Schedule with a big gun receiver station

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Love Thy Neighbor ( except in Palmdale )
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EME using 2 meters
Us 150 watts USB, bandpass off, AGC off, into a
2 m Yagi pointed at the moon. Us the RigBlaster
for the digital communication mode, CW , Rtty,
PSK, WSJT, JT65B, MAP65, WSPR Get K1JT software
http//physics.princeton.edu/pulsar/K1JT/ You
need a computer to run RigBlaster and
Software EME path loss is 240 db or more on the
propagation Best time for EME is the moon at
Perigee (closest) A low temperature Pre-amp will
help also A 12.5 dBd or 14.6 Dbi gain
horizontally polarized (not circular) antenna
yagi LM400 or Belden 9913 coax. Do not use RGs
of any type Antenna Tracking software, W5UN
Skymoon and others
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KB8RQ has a big Gun Array
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Some Hams just got to have bigger is better
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I dont see any small Dishes? So, BUDs probably
dont work that well
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The Milky Way in RF
Where is Mr. SETI
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The amateur level of SETI looking in RF
Frequencies is out of the question.
For SETI, Size Matters.
100 foot Arecibo Dish in Puerto Rico
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The New SETI is looking at stars for Photon
modulations
Almost any telescope of amateur size can be used
for photon monitoring of the stars. Presently
there is a Space Satellite pointed at one small
region of the galaxy in hopes of recording photon
changes that are of human nature. The current sky
conditions around the world are making astronomy
a fading sport.
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From http//www.setileague.org/editor/possible.ht
m

• Is Amateur SETI Even Possible?by Dr. H. Paul
  Shuch, Executive Director
• Recent link calculations have revealed what
  should not particularly surprise experienced
  weak-signal radio amateurs the best ham SETI
  station we can assemble appears unable to
  communicate with its counterpart at the distance
  of the nearest star. This finding has generated
  concern within the SETI community. "If your
  system wouldn't detect the strongest signal the
  ETI might radiate," SETI pioneer Dr. Bernard M.
  Oliver told me recently, "even if it came from
  the nearest star, then years of listening, or
  thousands doing it, won't improve the chance of
  success. To cross the Golden Gate, we need a
  bridge about 10,000 feet long. Ten thousand
  bridges . . . one foot long won't hack it." I
  must admit, Barney makes an excellent point. And
  yet I am not discouraged. Why? In part, because
  the Golden Gate Bridge analogy assumes a serial
  process, whereas SETI may indeed prove a parallel
  enterprise. In addition, the crux of his argument
  seems to rest on how we define "the strongest
  signal the ETI might radiate." And this is so
  entirely unknown as to make speculation futile.
• What happens to our range, for example, if a ham
  SETI station tries to receive not itself, but a
  MegaWatt signal from an Arecibo-type antenna? The
  additional antenna gain at one end of the path
  increases system range by perhaps two orders of
  magnitude, to tens of light years. And what if
  the ETI possesses a Cyclops? Now our potential
  contact range increases another order of
  magnitude, into the hundreds of light years. Is
  amateur SETI futile? Not if our galactic
  neighbors are more successful than we in getting
  their governments to fund large-scale antenna
  arrays. So ironically, it just might be the
  distant success of Oliver's own brainchild which
  gives hope to amateur SETI.
• Hams have always been innovators, and one cannot
  begin to anticipate the spin-off technologies
  which might result from the search. Just as the
  thousand monkeys at a thousand typewriters might
  some day write out the whole Encyclopedia
  Galactica, might not a thousand digital signal
  processing experimenters, pushing a thousand
  different algorithms, someday find the key to
  digging another 20 dB into the noise? It would
  seem that amateur SETI is a no lose scenario,
  even if we hear not a peep from the stars.

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• I think this puts to bed the idea of doing any
  type of deep space receiving by an amateur
  station. Most areas would be way to EMI noisy
  and may not allow extensive arrays of antenna.
  Feed line loses are too great for most any setup.
• So, think astronomy photon counting.

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Review of Radio Telescopes
Arecibo Observatory Radio Telescope in Mountain
Side in Puerto Rico, 1963, 1000 ft wide
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Jodrell Bank Radio Telescope
Jodrell Bank England, UK, 1945, 250 Feet,
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U S Naval Laboratory
Some where back east I think was this telescope
of the 1950s. 80 footer.
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The SETI Radios
Following a recent demonstration of a 10-dish
element of the Allen Telescope Array, the U.S.
Navy has signed off on a 1.5 million agreement
to use the array along with another 10-dish
installation to be developed in the near future.
When complete, the ATA will consist of 350
20-foot (6.1-meter) dishes. Twenty dishes are
currently online at the observatory with a
42-dish array total to be completed near the end
of the year. Though the project is slightly
behind schedule due to the recent heavy northern
California winter and the usual challenges of
engineering a radical new technology, one of the
projects leaders is particularly pleased by
recent progress.
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Green Bank of West Virginia
300 Foot, 1950s, this one fell down in 1999.
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New Green Bank Telescope
OrganizationNRAO LocationGreen Bank, West
Virginia, USA Wavelengthradio telescope and
microwave band Built1991-2002First light August
22, 2000 Telescope style Parabolic off-axis
reflector, Gregorian optics Diameter100m
Collecting
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Radio Telescope at Harvard
60 footer.
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Cornwall Goonhilly, UK Radio Telescope
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Now, Amateur Built Radio Telescopes
5.2 meter, for 1420 MHz neutral Hydrogen
listening.
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New Mexico Institute NRAO
In a cooperative effort with New Mexico Institute
of Mining and Technology, NRAO has built the
N2I2 NRAO/NMT Instructional Interferometer. It
is a 2-element adding interferometer located at
the Etscorn Campus Observatory at New Mexico
Tech. The dishes were purchased from CASSI, are
10' in diameter, 25 meters apart on an east/west
baseline, and use the SRT pointing software. The
21cm receivers are from Radio Astronomy Supplies.
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Chippewa Valley Astro Society
5 Meter,
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Parabolic Horn PA0AVS, The Netherlands
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Goldstone Apple Valley, CA.
How about a tour of this site? Contact JPL?
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CalTech Ownes Valley, Bishop, CA.
Solar array
40 meter