Dear Simon VE7SXS
Is your observatory located in Terrace, British Columbia ?
In 1988 I drove through Terrace and visited Prince Rupert, I had been
camping in Alaska, Yukon, BC, and traveled south along the Cassiar Road
:
https://www.google.com/maps/@54.52025,-128.599622,13z
https://www.google.com/maps/@54.52025,-128.599622,8z
I think a VERY important section of the Radio Jove Project Antenna Manual
https://radiojove.gsfc.nasa.gov/telescope/ant_manual.pdf
is section 4.1, "Site Requirements and Considerations"
page 20
... The best location may be a sports field or a RURAL SETTING ...
Avoid being surrounded by buildings, a low interference level is VERY VERY
VERY important.
Good luck
We look forward to studying your reports in the Data List, subscribe at:
https://lists.nasa.gov/mailman/listinfo/radiojove-data
Warmest regards
--... ...-- November 7 Yankee Bravo Victor :)
--------------------------------
Introductory Radio Astronomy references
http://herrero-radio-astronomy.blogspot.com/2015/06/introductory-radio-astronomy-references.html?m=1
Jupiter events at STEREO A and WIND for correlation with Juno Waves
http://herrero-radio-astronomy.blogspot.com/2016/12/jupiter-events-at-stereo-for.html
Links to Juno related posts
http://herrero-radio-astronomy.blogspot.com/2016/01/links-to-juno-related-posts.html?m=1
Sun Earth Jupiter event posts:
http://herrero-radio-astronomy.blogspot.com/2017/02/sun-earth-jupiter-20170312.html
http://herrero-radio-astronomy.blogspot.com/2015/08/links-to-monthly-sun-earth-jupiter-posts.html?m=1
Solar Cycle 24
https://en.wikipedia.org/wiki/Solar_cycle_24
"The Solar Cycle" by David Hathaway 2015, 81 pages
http://arxiv.org/pdf/1502.07020v1
Driel-Gesztelyi and Green 2015 "Evolution of Active Regions" 98 pages, 11
MB:
http://link.springer.com/content/pdf/10.1007%2Flrsp-2015-1.pdf
Links to recent Solar Radio Science Highlights by Eduard Kontar
http://herrero-radio-astronomy.blogspot.com/2017/02/links-to-recent-solar-radio-science.html
Solar Type Examples
http://herrero-radio-astronomy.blogspot.com/2015/07/solar-type-examples.html
Solar Dynamics Observatory - Now and Daily - Images Movies
http://sdo.gsfc.nasa.gov/data/
NOAA SWPC Solar Event reports with README description of their format
ftp://ftp.swpc.noaa.gov/pub/indices/events/
Preparation for Eclipse 170821
http://herrero-victor.blogspot.com/2016/10/preparation-for-eclipse-170821.html
-----------------------------
Dr. Eng. Victor Herrero-Arrieta Ph.D. M.S. Ing.Ind.
http://herrero-radio-astronomy.blogspot.com/ Radio Astronomy Blog
http://herrero-victor.blogspot.com/ Astronomy Blog
http://victorstravelpictures.blogspot.com/ Travel pictures
On Tue, Mar 14, 2017 at 6:00 PM, Jim Sky <radiosky@xxxxxxxxxxxx> wrote:
Hi Simon,
Thank you for the nice detailed description of the situation. I am going
to forward this along to the Radio Jove list because there are some smart
people on there who deal with these issues constantly. But I will throw in
my 2 cents here.
If you are going to use 50 ohm coax I suggest you use RG-8X instead of
RG-58U because it has lower loss but more importantly better shielding on
your long cable run to the antenna. 50 ohm coax has no advantage over the
70 ohm coax in these systems.
For Jupiter from your location the maximum elevation will be in the 35
degree area. If you can do 20' height, you will do a little better than at
15, but i understand the trade-off in effort.
if you have a system that is 50 ohms throughout, I don't believe you need
to have a multiple of a half wavelength in the coax run back to the
receiver. Of course, that statement does not apply to the phasing cable
and the other feed cable on the antenna side of the splitter.
I think baluns are a good idea. That antenna analyzer should come in
handy too.
If I am correct I believe a 135 deg. phasing cable for a coax with a
velocity factor of .66 at 20.1 MHz will be 12.12 feet.
The antenna manual from the Jove site is an excellent guide if you don't
have it.:
https://radiojove.gsfc.nasa.gov/telescope/ant_manual.pdf
Best Wishes,
Jim
On 3/14/2017 5:42 PM, College Professor Simon Thompson wrote:
Hello
I need help determining the lengths of the various coaxial cables that I need
to assemble the cable assembly for my radio telescope.
I will try to include all of the data that is relevant to my particular
situation.
I am using an HF receiver with 50 ohm inputs.
I have a power combiner that uses 50 ohm inputs.
I would like to use RG58/U cable; this has a velocity factor of 0.66.
The antennas will be at a height of 15 feet, if this is acceptable. If they
need to be at 20 feet in order to facilitate reception from my location, that
will be possible.
My GPS coordinates are:
N 54 31 12 90
W 128 35 58 64
I think I will need to use 135 degree phasing in order to receive a signal
from Jupiter, and to ensure that I can receive a signal over the next few
years.
My antenna array will be about 100-150 feet from the receiver location, and I
am not sure what length of cable to use from the combiner to the receiver. I
think it needs to be some multiple of the 20.1 MHz wavelength, if I have read
correctly.
I have also acquired two 50-ohm baluns to act as the centre of the antennas,
but I do not need to include these if they will interfere with reception of
the signal.
I have an antenna analyzer.
i am a licensed amateur: VE7SXS.
I am using your RadioSky Pipe software!
