It could be a combined time display with a channel number and
measured value, from some kind of data logging instrument. LN was
big in thermocouple measurements and the like. With those digits you
could show temperature at three digits resolution, selected channel
00-99, and hours and minutes,
Simon,
This is a fantastic idea and I have every intention of trying to
replicate it at home with tools on hand. Thanks for sharing, and I
hope you can show off some results.
On Wed, Oct 8, 2014 at 1:09 PM, Simon Marsh subscripti...@burble.com wrote:
I've been a lurker on time-nuts for a while,
Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun
aligned with the satellite and my dish. So I was wondering what kind of effect
this has on the GPS system and especially timing receivers.
Bob - AE6RV
___
time-nuts mailing
Bob -
I do not believe it has any effect. The DirecTV satellites are geostationary at
about 22K miles. I used to experience the same phenomenon in the late 70's with
my TVRO receiver at C band. GPS has some 36 or so satellites in a Medium Earth
Orbit (MEO). Blockage, if it can even occur due
If you had an exact timing for the outage, would that
have told you the beam-width of your antenna?
-- project for next spring :-)
On 10/9/2014 1:04 PM, Mike Feher wrote:
Bob -
I do not believe it has any effect. The DirecTV satellites are geostationary
at about 22K miles. I used to
b...@evoria.net said:
Two days this week, there was a 3 or 4 minute outage on DirecTV as the sun
aligned with the satellite and my dish. So I was wondering what kind of
effect this has on the GPS system and especially timing receivers.
Is there any easy way to get a signal/noise reading out
Henry,
I have more information and you may have explained it. The outages occurred at
about 3:10PM, and with an azimuth here of about 180 degrees (which I just
looked up), that makes no sense. Also, the cartoons I was recording for my
granddaughter were unaffected, but the station I was
On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray hmur...@megapathdsl.net wrote:
What's the beam width of the DirectTV antennas? Does it agree with the 3 or
4 minutes at the back-of-envelope level?
DirecTV is a Ku/Ka-band system operating with a 460mm dish antenna.
At Ka-band, the 3dB full-width of
Standard GPS receiving antennas have a large beam width in order to cover
most of the sky. Even in the Oregon Rainforest the sun is in view most of
the day.
Some satellite transponders have more power and are less prone to
interference
as they pass in front of the sun.
Typical home TVROs
Exactly geosyncs have sun outages as the sun aligns with the sat and your
dish.
GPS because the sats are distributed do not suffer from the effect.
Regards
Paul
WB8TSL
On Thu, Oct 9, 2014 at 2:04 PM, Mike Feher mfe...@eozinc.com wrote:
Bob -
I do not believe it has any effect. The DirecTV
The sun can have some effects on GPS signals, particularly when doing
ultra-precisiony sorts of things.
Version 4 of Lady Heather calculates the sun (and moon) positions (and moon
phase) and can display them as part of the satellite position map (and analog
watch display). This feature was
Where is this Version 4 available?
On 10/09/2014 01:28 PM, Mark Sims wrote:
The sun can have some effects on GPS signals, particularly when doing
ultra-precisiony sorts of things.
Version 4 of Lady Heather calculates the sun (and moon) positions (and moon
phase) and can display them as part
You pick up satellite TV with a parabolic dish that points at one spot
in the sky where the geostationary satellite lives. A sun outage
happens when the sun wanders into the focus and overloads the receiver
with noise that drowns out the satellite signal (at least, it raises
the noise floor enough
On 9 Oct 2014 22:17, Andrew Rodland and...@cleverdomain.org wrote:
You pick up satellite TV with a parabolic dish that points at one spot
in the sky where the geostationary satellite lives. A sun outage
happens when the sun wanders into the focus and overloads the receiver
with noise that
I'm looking for the A12 18V power supply and A8 secondary 5 MHz OCXO
modules for an attempt to resurrect my Cesium unit before it gets too
heavy for me to wrestle with... Does anyone have a parts unit or junker
that they might be able to supply these from please?
Thanks,
Dan
If you have an interest in trying to measure sun noise, you might like
to have a look at the itty bitty radio telescope.
(watch the line wrap)
http://www.arrl.org/files/file/ETP/Radio%20Astronomy/Build%20a%20Homebrew%20Radio%20Telescope-QST-0609.pdf
Hi Bob:
The geostationary sats are in a 24 hour orbit. The orbit is also in the plane of the Earth's equator. Because of these
two facts they appear stationary.
Also because of that twice a year near equinox the Sun will be directly behind
the sat and the C/N goes to pot so no signal.
I
Hi Dave:
The small size of the Ku-band TV dish and that it's surface is covered with a flat type paint means there's little or
no thermal heating of the receiver or feed.
There were cases with the early C-band TVRO systems where they did melt the
receiver.
Have Fun,
Brooke Clarke
On 9 Oct 2014 23:28, Brooke Clarke bro...@pacific.net wrote:
Hi Dave:
The small size of the Ku-band TV dish and that it's surface is covered
with a flat type paint means there's little or no thermal heating of the
receiver or feed.
There were cases with the early C-band TVRO systems where
Hi Graham:
Do you know if anyone has used a Ku-band receiver, like described in the paper,
to look at Jupiter?
The Radio Jove project is looking between 18 and 40 MHz.
http://radiojove.gsfc.nasa.gov/
Have Fun,
Brooke Clarke, N6GCE
http://www.PRC68.com
Folks,
We look after 5 separate hydrogen masers spread all over Australia and we
collect tic phases between the masers and the GPS.
On around ~Oct 7 we have noticed that the normal steady straight line (with
standard daily noise) took a noticeable downward turn - on all 5 masers.
Did anyone
Hello Jim,
I am just a novice here - but, when you say noticeable, can you please tell
us how noticeable? What is a small downturn vs. a noticeable one?
I just put up an outdoor GPS antenna. If there is anything I can do to
possibly help, please give me instructions.
I do not have direct
Hello all...
Not all satellite TV antennas are parabolic. A typical C-Band antenna is
parabolic and aligned for one satellite. But, that could change if the
feed was modified to receive multi-satellites, while the shape of the
reflector remained parabolic. Or the antenna could be an
Hi Don:
It's my understanding that all satellite dishes have a parabolic curve which
focuses the signal on the feed.
The C-band dish has a round outline and the feed is located along the dish
center line.
Most commercial Ku-band antennas have a parabolic curve, but have a elliptical or orange
Simon,
I breadboaded a set-up in March using 74AC74's and two 10 MHz Micro
Crystal oscillators (5V square wave), one as the coherent source and one
as the 10Hz offset clock. I had no glitch filtering as described in the
article you cite (CERN's White Rabbit Project, sub nanosecond timing
Hi
GPS is steered by the Air Force last time I checked.
A really good place to check is the NIST Time and Frequency pages that show
both real time and historical data for each GPS sat compared to NIST time:
http://www.nist.gov/pml/div688/grp40/gpsarchive.cfm
Hopefully it’s accessible via
Hi Brooke...
You are correct. My semantics were confusing!
The offset feed certainly has an advantage because of no shadowing,
but a lot of commercial Ku-Band antennas are complete parabolic
reflectors with a sub-reflector and cassegrain feed.
There obviously is some loss because of the
On Thu, 09 Oct 2014 18:14:55 -0400
Graham planoph...@aei.ca wrote:
If you have an interest in trying to measure sun noise, you might
like to have a look at the itty bitty radio telescope.
(watch the line wrap)
Le 10 oct. 2014 à 03:09, Bob Camp a écrit :
Hi
GPS is steered by the Air Force last time I checked.
A really good place to check is the NIST Time and Frequency pages that show
both real time and historical data for each GPS sat compared to NIST time:
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