Contents:
An Apology
Radio-SkyPipe Beta is Here!
"Listening to Jupiter", a new book.
Amateur Radio Astronomer Interview: Thomas Ashcraft
Amateur Tip #4
Featured Site
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An Apology to Subscribers
It has been many months since the last issue of the Radio-Sky
Journal. The reasons for the delay are many but most are related
to our move to Hawaii. We arrived here on the Big Island on the
25th of December, 2000. It will take some time to settle in, get
a high speed internet connection and unpack our things whenever they
arrive.
Please be patient if you place an order with us in next the few weeks.
At the time of this writing, most of our products have not yet arrived
here in Hawaii.
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Radio-SkyPipe Beta is Here!
The long promised, internet enabled, data collection program is
finally available on my web site. Radio-SkyPipe provides you
with
a means to put your observatory on-line in real-time. Here is a
brief summary of the programs functionality:
1. Use as a stand alone data collection program sampling via your
sound card or a simple, inexpensive, 12 bit ADC.
2. Stream your data in real time to multiple clients via the internet.
A permanent IP address is not needed. Your site can be
accessed
by anyone else with Radio-SkyPipe software if you chose
to
make it public.
3. Connect to any public Radio-SkyPipe server, stripchart, and save
the file, complete with embedded header information about
the
files origin.
4. Chat online with others connected to the same server.
The program is free!
Just go the my website http://radiosky.com and click on the download
icon.
You can see the help file and installation info at:
http://www.radiosky.com/skypipehelp/skypipe1beta.html
Note: The Beta version presently available on the website expires
on Feb 1, 2001, but a new version without this limitation will be
made available before then.
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"Listening to Jupiter" a New Book by Richard Flagg
Monitoring Jupiter's decametric radio noise storms is one of the best
ways to introduce yourself to amateur radio astronomy. Veteran radio
astronomer and engineer, Dick Flagg, has written a new book,
"Listening to Jupiter", which guides you through the process of
assembling an observatory and making radio observations of these
mysterious signals.
"Listening to Jupiter" is written in clear, simple language that is
appropriate for the absolute beginner, but even long time observers
will gain from Dick Flagg's insights and years of experience as a
Jovian radio astronomer. When to listen, receiving equipment, antennas,
data recording, and advanced projects are all covered. This book has
a spiral binding for easy placement on the workbench or in the
observatory.
See the full table of contents at: http://radiosky.com/newLJTOC.html
"Listening to Jupiter" is available at our website for $22 plus $3.20
shipping in the US and $10 shipping elsewhere.
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An Interview with Thomas Ashcraft
If you have been an amateur radio astronomer for very long, you probably
know Tom Ashcraft's name. Tom is the most active amateur observer I
know.
His energy and rigorous approach is inspiring. I am sure you will
enjoy the following interview.
RS: How did you come to be interested in radio astronomy? Were there
any
books or people that influenced you?
TA: I moved to New Mexico in the late 1980s and soon learned that this
is a
place where the sky determines people's lives to a great degree. I
got very
interested in astronomy and especially the Sun. In May of 1991, I bought
an
80 mm optical refractor telescope and began a daily regimen of sunspot
drawings. The day I got the telescope, there was a tremendously active
sunspot region on the Sun and this spot group turned into one of the
most
dynamic storm producing regions in recorded history. That was
a fortuitous
beginning to my astronomy work.
Optical solar observing in white light is interesting but the Sun is
dynamic in the broader spectrum and there are many more levels of "seeing",
(like radio-seeing). I wanted more sensitivity in my observations,
a deeper
connect. I can't remember the year, (maybe 1992?), but I came
across a
magazine article in Science Probe Magazine (now defunct) by Jeff Lichtmann
that gave actual plans on how to build various sorts of radio telescopes.
It gave the possibilities of hearing the Sun, Jupiter, and exotic things
like quasars. This intrigued me. Some strong urge to manifest my own
radio
telescope set in.
But getting started in radio astronomy was difficult right from the
start.
I don't have a background in electronics and I couldn't seem to get
much
circuitry help locally. It seemed like a year or two went by without
much
progress but the idea of a radio telescope was never far from my attention.
But I was making no actual physical progress. I was stuck.
Then a couple of good things happened.
One good thing was finding an article in Sky and Telescope Magazine
that
gave instructions on how to observe the Perseid meteor shower by FM
radio.
(Lynch, J.L., A Different Way to Observe the Perseids. Sky & Telescope,
August 1992, pp. 222-225.) As per the instructions I bought a
$20 Radio
Shack yagi, some antenna wire and hooked it all up to my FM tuner and
set
up to hear what a meteor might sound like. To my amazement it worked.
I
heard some forward scatter reflections, some "Blue Whizzer" Perseids.
That
was finally some actual radio astronomy, some real deed, and
it felt very
satisfying.
Another good thing, great thing really, was the advent of the internet.
I
began to connect with a few others who had similar pursuits. I discovered
online "The Radio Meteor Observer's Bulletin" published by Chris Steyaert
in Belgium. It was a place for real data. I joined SARA in 1993 or
so. That
was a helpful step.
As I answer your question, I realize I could write on and on about the
path
into radio astronomy but it would take up too much space! But
here are
some keywords and inspirations:
The independent work of inventor Grote Reber.
Visiting the VLA (Very Large Array). This is like a wonder of the world
to
me.
Radiopanspermia and the "diseases from space theories" of Hoyle,
Wickramasinghe, Arrhenius.
Book: The Invisible Universe by Gerritt Verschuur.
RS: Please briefly describe your radio astronomy activities; the types
of
observations you do and the equipment you use.
TA: I do daily Sun and nightly Jupiter observations. I am interested
in audio
waveforms and have been capturing all sorts of wave phenomena on tape.
There is a great variety of bursts and emissions from outer space.
My solar radio array is very sensitive at the frequencies I work at.
It is
neat to hear "fast drift bursts" hit on one radio at 50 MHz and then
at 29
MHz on the next radio.
I can sometimes hear and see the beginnings of "coronal mass ejections"
on
my charts and can tell that something important is in process and can
thus
alert the network of solar observers.
Jupiter at decametric wavelengths has become a pre-occupation for me
here
in the year 2000. For Jupiter, I run three radios and keep three chart
recorders going and one stereo audio recorder. Working from 18 through
23
MHz gives a good indication of any strong Jovian activity. My
system runs
smoothly and automatically through the night and I put a tape in before
bed
and check my charts in the morning to see if there was any bursting
in the
night. If I see possible Jupiter I run my audio tape and listen to
verify
the reception.
There is all sorts of diversity in Jupiter emissions. As far as
I can tell
there are only a handful of observatories collecting serious and consistent
data.
Equipment:
For Jupiter and the Sun I use essentially the same radio array and
components.
Radios:
Two Sangean ATS-803 short waves with the AGC desoldered and wired around.
ICOM R-75
One old Sanyo shortwave for WWV Universal Time signal.
Data logging:
I use old fashioned Rustrak paper strip chart recorders and have not
quite
moved into computer data logging as yet. I also spend a lot of time
under
headphones listening in real time and making copious notations into
notebooks.
Audio recorders:
Panasonic stereo Hi-Fi VCRs. (Makes an eight or even ten hour long
stereo
audio tape with two radios feeding in.) I have one VCR for continuous
recording and another for playback.
Antennas:
Half wave dipoles cut to frequency.
For the Sun I work at 50 MHz and 29 MHz. The upper frequency limit
of the
ICOM is 60 MHz but I have found 50 MHz consistently useable. The Sangean
short waves go up to 29.999 MHz.
For Jupiter I use the exact same system but change to lower frequency
dipoles,(23 MHz, 20.1 MHz and 18 MHz).
Logbook. Pencil and paper. Very important.
Forward scatter meteor observing:
I did forward scatter meteor work for some years and developed a
hyper-sensitive array that incorporated four separate FM radios/antennas.
From my observatory in New Mexico I can observe out over the Great
Plains
states up into Minnesota, Wisconsin and to the east to the Mississippi
River
and to the south into Texas. I got interested in fireball detection
after
the 1994 Comet SL-9 crashed into Jupiter. I observed then for meteoric
fireballs for a year or two and worked in conjunction with the Air
Force
for a while. That was interesting.
Equipment:
Technics FM tuner, JVC FM tuner
Radio Shack FM yagi antennas
Headphones.
Rustrak strip chart recorders (not recommended for meteor work)
Panasonic VCR
Logbook.
RS: Many amateur radio astronomers seem to spend most of their energy
developing their equipment, and never come up with a systematic approach
to
observing. How do you balance observing vs. equipment construction?
By predilection I am an observer. The capacity for long term and consistent
observation may be a configuration of individual personality traits
or
perhaps quirks. I don't know if a disciplined observational temperament
can
be willed.
I have utmost appreciation for my radio telescope system since it contains
many hours of work and problem solving. To build a research grade radio
telescope array and establish reliable baselines is a long and dedicated
task.
I'm not that much of a hardware person. When my system is running smoothly
then I don't even jiggle a wire. But I do love my system. My radio
telescope
is like an extension of my body. I consider my antennas to be my own
hyper-extended nervous system.
RS: How do you view the amateur radio astronomy "community"? How would
you
like to see it evolve?
TA: The key in radio astronomy and all science is correlation and verification.
This is especially important in radio astronomy where there are many
sorts
of interferences that mimic extra-terrestrial signals. If you're working
all alone it can be hard to prove a specific reception. Hence the community
is of utmost importance.
The community is a good one. When I began these endeavors the internet
was
just beginning to bloom. I was isolated in my interests. But then other
observers appeared and I have done a great deal of synchronous observing
with folks in other parts of the world. For example, you can radio
observe
the Perseid meteor shower in Europe and the Americas at the same time.
The
shower radiant is above the horizon in both parts of the world. It
is
amazing to record the peak of the Perseids and confirm the same essential
results as others far away. And communicate in real time via email.
It is
great.
Presently, I am observing Jupiter in conjunction with the Radio Jove
Project. There have been three instances of joint observing and a
conference call during the session. While on the conference call I
received
Jupiter bursts in real time that were received by observatories in
Florida,
New Mexico and Hawaii.... this is exciting.
RS: Do you see a strong potential in amateur radio astronomy for genuine
contribution to science? How does one gain credibility as a scientific
contributor with amateur status, or is this even possible?
Of course, there is the potential for real contribution. Science is Science.
I wonder though. If a person is a practitioner of true science then
why
even bother to use the qualifier "amateur"? Ultimately it is not what
is
said but is the data presented. If the data is impeccable and holds
up
under scrutiny then it is science. Credibility is earned by consistency
of
solid observation.
I do admit to having a little difficulty with the word "amateur" as
it has
come to be understood at times. There is a gray area where amateur
science
merges with hobby science and this doesn't serve the serious amateur.
I
have nothing against hobbyism but this is a question I address from
time to
time.
RS: After all of your hours of observation of the Sun and Jupiter, is
there
any excitement left for you in these activities? Is there another
emotion
which better describes what you derive from doing radio astronomy.
Is
there any perceived "spiritual" connection?
TA: This work is pure excitement. It is never static. Even days of solar
quietude are interesting. During sunspot minimum years there were actually
weeks of absolutely no sunspots. A perfect Sun. That's interesting
in and
of itself.
Jupiter is a mysterious frontier. The mechanisms of its radio bursting
are basically little understood. Jupiter is a fluid planet and observing
and noting when it emits is like mapping an unknown world.
It's possible that life in space will be first discovered on the Jovian
moon Europa in a warmish ocean. This discovery may happen. Even soon.
Is there any perceived "spiritual" connection? Well, I'm not all that
spiritually inclined and especially not divinely inclined. But,
inter-species kinship propels my studies and the possible "intelligence"
of
all nature stimulates my work. Things like extra-terrestrial microbial
intelligence, viral urges, waveforms as communication between species.
This is the interesting stuff and to me it is the heart of radio astronomy.
RS: Do you have new projects on your horizon?
TA: I am working to get my website fluid and hopefully will be able
to post
fresh observations and sound files. The URL is http://www.heliotown.com
I want to put out some CDs of sounds I have collected. I think there
might
be some sort of "nutrition" in these extra-terrestrial waveforms or
maybe a
way to entrain with the sound for shifting body and mind states. It
sounds
a little science fictional maybe. But I would like to find ways to
enter
into the waveform and make it accessible to others. This is interesting
to me.
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This Amateur Tip was submitted by Robert Rolf. Thank you Robert.
Amateur Tip #4
When adding in offsets to op-amps, always use a separate precision
voltage reference (like an LM385) for your bias pot to remove power
supply variation as a contributor to the bias setting. Most op-amps
have very good CMRR (common mode rejection ratios), but they can't
do
a thing about a drifty offset input. For example a typical 78L05 would
give you a 20uV change for a 2 volt input variance (50dB RR), while
an
LM385 operating at 100uA would give you 6uV. The LM385 also has better
specs for tempco (80ppm) and long term drift (20ppm) while the 78L05
has
no spec, and is drifty as heck over temperature and time.
As an aside, when dealing with tiny voltage changes one most take into
account many thermocouple effects. A copper constantan thermocouple
generates 4uV/C so a copper, lead, tin, gold, aluminum junction chain
(as found with a IC lead) will have a significant and variable thermocouple
effect depending on the uniformity of the solder, metal purity, etc.
If you
are really serious about low signal levels one must temperature regulate
-every- possible thermocouple (dissimilar metal) junction or prevent
thermal gradients where such junctions are unregulatable. e.g.
copper-gold-gold-copper junctions of a connector since the two Sebeck
potentials will cancel out if both metal junctions are at the same
temperature.
This is why a temperature controlling jacket around an outdoor LNB makes
an enormous difference to the amplifier stability.
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Featured Site
The Windward Community College Radio Observatory
While not fully completed, the WCCRO site will provide you with the
ability to monitor Jupiter for a few hours even after the Sun comes
up on
the US mainland. Presently, the WCCRO is set up with a 20.1 MHz dual
dipole
antenna pointed at the zenith, however, a large log periodic array
is under
construction. You may listen to the audio from the WCCRO receiver using
Windows
Media Player 6.4 or above or you can see the real time stripchart data
stream
using Radio-SkyPipe, (or both!).
http://jupiter.wcc.hawaii.edu
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