Jim Lux wrote:
WHy yes they do: that's what weather radar is. It detects the reflections
> from the rain drops or ice crystals in the storms. ...
But radar is much different than passively receiving known radio signals
that penetrate the atmosphere from above.
Conceivably one could have hundred
"Just to put that in perspective, we're measuring a few degrees of phase
shift in a 32 GHz signal on a path that is over a billion km long."
Now this is fully qualified nuttiness :)
Didier KO4BB
On October 10, 2014 8:17:13 AM CDT, Jim Lux wrote:
>On 10/9/14, 10:16 PM, Andy wrote:
>> Bob Stewa
time-nuts-boun...@febo.com] On Behalf Of Bob
Stewart
Sent: Thursday, October 09, 2014 1:40 PM
To: Time Nuts
Subject: [time-nuts] Sun Outage
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
Andy...
On DirecTV and Dish, in order to get channels beyond the basic package,
Dish and Direct both use additional satelites at different orbital
locations.
If you have only the basic package, you get one antenna and possibly only
one feed horn.
Dish for example can use a two antenna set
On 10/10/14, 4:21 AM, Bob Camp wrote:
Hi
Bringing this back to GPS…
The TV stuff is at about 8X the frequency of GPS. That makes a difference in
terms of things like rain. That said, yes, there probably is some giant
rainstorm that would impact GPS accuracy. Much more likely in a “I can only
On 10/9/14, 10:16 PM, Andy wrote:
Bob Stewart wrote:
It occurred to me that one could use satellite signals as a meteorological
instrument to measure the water density in the atmosphere above you. I
wonder if the NWS does that.
WHy yes they do: that's what weather radar is. It detects th
Hi
Bringing this back to GPS…
The TV stuff is at about 8X the frequency of GPS. That makes a difference in
terms of things like rain. That said, yes, there probably is some giant
rainstorm that would impact GPS accuracy. Much more likely in a “I can only see
a small patch of sky” situation.
M
To: Time Nuts
Subject: [time-nuts] Sun Outage
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
__
Bob Stewart wrote:
... Also, the cartoons I was recording for my granddaughter were
> unaffected, but the station I was watching had the outage. That doesn't
> all fit together unless it was the uplink that had the problem.
I don't think the uplink itself can have this problem.
But DirecTV u
On Thu, 09 Oct 2014 18:14:55 -0400
Graham 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)
>
> http://www.arrl.org/files/file/ETP/Radio%20Astronomy/Build%20a%20Homebrew%20Radio%20Teles
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 s
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 p
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 off-ce
t in my opinion. 73 - Mike
Mike B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
Stewart
Sent: Thursday, October 09, 2014 1:40 PM
To: Time Nuts
Subject: [time-n
On 9 Oct 2014 23:28, "Brooke Clarke" 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 they did melt
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
http://ww
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 hav
lvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
Stewart
Sent: Thursday, October 09, 2014 1:40 PM
To: Time Nuts
Subject: [time-nuts] Sun Outage
Two days this week, there was a 3 or 4 minute ou
On 9 Oct 2014 22:17, "Andrew Rodland" 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 drowns out the satel
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
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 o
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 add
..@febo.com] On Behalf Of Bob
> Stewart
> Sent: Thursday, October 09, 2014 1:40 PM
> To: Time Nuts
> Subject: [time-nuts] Sun Outage
>
> 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 wha
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 have
On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray 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 the beam is 2.4 degr
ewart ; hmur...@megapathdsl.net
Sent: Thursday, October 9, 2014 2:27 PM
Subject: Re: [time-nuts] Sun Outage
On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray wrote:
> What's the beam width of the DirectTV antennas? Does it agree with the "3 or
> 4" minutes at the back-of-envelo
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 o
rt
> Sent: Thursday, October 09, 2014 1:40 PM
> To: Time Nuts
> Subject: [time-nuts] Sun Outage
>
> 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 th
-boun...@febo.com] On Behalf Of Bob Stewart
Sent: Thursday, October 09, 2014 1:40 PM
To: Time Nuts
Subject: [time-nuts] Sun Outage
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 th
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
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