I saw a rather expensive GPS antenna made by one of the
big-name GPS survey equipment mfgrs that was mounted
on top of a 12 or 15 inch diameter disc about 3/4 inch thick.
Turns out that the disc is made of some sort of RF absorbent
foam covered by a weather-proofing coating of some sort.
If
: Re: [time-nuts] Improving performance of a GPS antenna...?
Hi Mike:
I used military surplus radar absorbing material to stop reflections on a
satellite antenna by applying it to the rain
gutter, see:
http://www.prc68.com/I/Images/SB_angw.jpg
A sheet of this stuff about 4 x 6 feet weighed maybe
Jim,
There's a new choke ring style antenna (patented, of course, and they
deserve it) which uses spikes instead of solid rings. And, they wrap the
choke over a hemispherical surface as opposed to on a plane.
Much tougher to design and fabricate (no buying sets of cake pans any
more), but
What sort of interference?? What is causing it? Any possibility of
correcting it?
I am interested in more information. Will look for whats later in the
thread. I have a situation where there is interference coming from a
specific direction (close to the horizon). Is it feasible to
How do you know it is coming from a specific direction? There is a
terrestrial L-band transmitter? A radio link? Try to put a screen
n*lambda+lambda/2 from the GPS antenna to create a null for the offending
L-band frequency...
On Thu, Apr 5, 2012 at 2:49 PM, Chuck Forsberg WA7KGX N2469R
avril 2012 14h49
À : time-nuts@febo.com
Cc :
Objet : Re: [time-nuts] Improving performance of a GPS antenna...?
What sort of interference?? What is causing it? Any possibility of correcting
it?I am interested in more information. Will look for whats later in the
thread. I have a situation where
Hi,
Are you sure that the Oncore VP sends the right voltage to the antenna?
This type needs 5 V and most pucks are designed for 3.3 V . According
to the manual the VP sends 5 V to the antenna but anyway it is easy to
measure.
Regards,
Ignacio, EB4APL
On 05/04/2012 3:43, Morris Odell
On Thu, Apr 5, 2012 at 2:28 PM, EB4APL eb4...@cembreros.jazztel.es wrote:
Hi,
Are you sure that the Oncore VP sends the right voltage to the antenna?
This type needs 5 V and most pucks are designed for 3.3 V . According to
the manual the VP sends 5 V to the antenna but anyway it is easy to
Thanks for the replies.
Yes it's definitely 5V from the receiver.
That advice re the pipe mount sounds good - that will be the next step!
Morris
--
Are you sure that the Oncore VP sends the right voltage to the antenna?
This type
You could cut up a military surplus RF blanket :-) For those who don't
know, you cover the radome of an aircraft with this when the radar is
transmitting, so you don't cook anyone nearby. I never knew how
effective it was, but I didn't walk in front of the aircraft, just to
be safe.
Joe Gray
W5JG
You can get inexpensive conductive foam from Amazon.
On 4/4/2012 5:53 AM, Michael Baker wrote:
Hello, Time-Nutters--
I saw a rather expensive GPS antenna made by one of the
big-name GPS survey equipment mfgrs that was mounted
on top of a 12 or 15 inch diameter disc about 3/4 inch thick.
Turns
So it can be done: try to emulate the Zephyr GPS antenna with the RF
absorber.
On Wed, Apr 4, 2012 at 3:56 PM, Robert Berg bo...@pobox.com wrote:
You can get inexpensive conductive foam from Amazon.
On 4/4/2012 5:53 AM, Michael Baker wrote:
Hello, Time-Nutters--
I saw a rather expensive
On 4/4/12 6:56 AM, Robert Berg wrote:
You can get inexpensive conductive foam from Amazon.
Not all conductive foam works as a decent RF absorber. If the
conductivity isn't well matched to 377 ohms, then the RF reflects right
off of it. The black foam that ICs used to come in is a good
If foliage does such a number on GPS signals, just fill a big garbage bag
with yard debris and set the antenna in the middle of that.
On 04/04/2012 05:53 AM, Michael Baker wrote:
Hello, Time-Nutters--
I saw a rather expensive GPS antenna made by one of the
big-name GPS survey equipment mfgrs
On 4/4/12 7:35 AM, Chuck Forsberg WA7KGX N2469R wrote:
If foliage does such a number on GPS signals, just fill a big garbage bag
with yard debris and set the antenna in the middle of that.
*wet* yard debris..
___
time-nuts mailing list --
Hi Mike:
I used military surplus radar absorbing material to stop reflections on a satellite antenna by applying it to the rain
gutter, see:
http://www.prc68.com/I/Images/SB_angw.jpg
A sheet of this stuff about 4 x 6 feet weighed maybe 40 pounds. An easy way to confirm it works is to use it
My first job was in a blasting cap plant in 1960. Raw materials and
finished product were kept in earthen bunkers separated by a distance
that would prevent an explosion in one from propagating (the distances
were found by experience).
Tall, grounded masts were spaced among the bunkers to prevent
Hi all,
While we're on this subject, I have a related question.
I recently bought one of those cone shaped Lucent GPS timing antennas from a
vendor in China. I'm using it for one of my GPS controlled clocks which
contains a 6 channel Oncore VP receiver and is on the end of about 15 feet
of
I mounted the antenna on a small Al plate about 10 X 20 cm attached
to a balcony rail 3 stories from the ground with a clear view of about 75%
of the sky.
I would have expected that the receiver would see quite a few satellites, a
similar arrangement with a magnetic puck antenna regularly sees up
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