Denny Page via time-nuts writes:
> No, no ground plane. Don’t really have a lot of room for that in the
> window. Out of curiosity, how large of an impact have you found with a
> ground plane?
As long as we're talking ceramic patch (puck) antennas, I've seen around
15dB improvement repeatedly (as
Hi
For a variety of reasons, a puck antenna is a bad choice for a lab timing
receiver.
Because the ground plane (and other issues like feed line) are a variable,
getting a
good pattern is a matter of luck. Multipath ( = low angle) rejection is rarely
going to
work well with them. They also
Yo All!
On Tue, 30 Apr 2019 22:52:26 + (UTC)
Taka Kamiya via time-nuts wrote:
> Yes, I saw your particular mention of survey antennas. My concern
> was that multi-path will affect any setup.
The best explanation I have seen is here, with lots of pretty graphs:
Hi
The pictures shown earlier are of a “survey antenna”. In the post I was careful
to refer to a “survey antenna”
as the point of the post. Ideally you want to be meters away from any metal.
Bob
> On Apr 30, 2019, at 5:42 PM, Taka Kamiya via time-nuts
> wrote:
>
> I can see that on survey
I can see that on survey situation but will it affect timing installations?
Will you give me an idea how far those bullet type antenna needs to be? My
antenna sits on a very short pole (2 feet?) and its base is mounted to frame of
my screened in porch. Roof and structure is aluminum, which is
Hi
You very much do *not* want to put a ground plane on one of the modern survey
antennas.(Chinese or US or Canadian or …) The better ones are very explicit
about this. They are optimized to sit on a pole in free air. Anything else and
the
pattern is degraded. ( = multipath gets worse)
Bob
Hi David,
No, no ground plane. Don’t really have a lot of room for that in the window.
Out of curiosity, how large of an impact have you found with a ground plane?
Btw, I love the pan!
Denny
Yes, Denny, choosing the baking tray (IIRC) was fun - I wanted as large
> From: Denny Page
> Initially, the units were connected to puck antennas that are literally side
> by side. At approximately 19:15, the units are taken off the puck antennas
> and connected to the single antenna through the splitter.
> I really didn?t expect such a dramatic change.
It does
Hi David,
No, no ground plane. Don’t really have a lot of room for that in the window.
Out of curiosity, how large of an impact have you found with a ground plane?
Btw, I love the pan!
Denny
> On Apr 30, 2019, at 00:34, David J Taylor via time-nuts
> wrote:
>
> Agreed with Dana's
Also, some receivers do a survey every time you power them up.
---
> If you move the antennas “far enough” (how far very much depends
on the design) the device goes back into survey mode.
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time-nuts mailing list --
Hi
There normally is a “survey in” process on a GPSDO. The location then gets used
to
help out the timing solution. If you move the antennas “far enough” (how far
very much depends
on the design) the device goes back into survey mode. While doing that, the
timing
may be less than ideal.
Bob
Denny,
That is certainly a large difference. But I'm not clear on one point that
could easily be very important:
Were the two antennas for the separate antenna test indoors, or on the roof?
If indoor, I kind of suspect that the difference might mostly be attributed
to the change in antenna
Hi Dana,
The antennas were in the window, top of the lower pane of a two pane window.
Certainly a better location that the antenna sitting on the desk.
There were several other units that showed similar behaviors. I suppose it’s
possible that there was interference. There were 7 antennas in 3
Denny,
That is certainly a large difference. But I'm not clear on one point that
could
easily be very important:
Were the two antennas for the separate antenna test indoors, or on the roof?
If indoor, I kind of suspect that the difference might mostly be attributed
to the
change in antenna
I don’t seem to be able to attach the pics to the emails correctly to allow the
mailing list software to process them. Rather than bombard everyone with any
more attempts, I put them up on Dropbox.
You can find the pics here:
https://www.dropbox.com/sh/fbbfuydqac5qqql/AAADkwrcVL8u5nkHvi8ecMe3a
[Resend—hopefully pics come through this time]
One additional interesting thing which I didn’t anticipate is the effect of
moving from multiple (puck) antennas to a single antenna.
The graph below shows the relationship between two LeoNTP units in the local
network as perceived by chrony. The
[Resend—hopefully pics come through this time]
Thanks Bob, this is in fact what I ended up doing. I bought a pair of the L1 /
L2 / L5 antennas from China, one for rooftop mounting at the new site, and one
for testing. I paired it with a splitter from GPS Networking. 35 feet of RG-213
from the
Hi
Looks like that should work. Don’t forget about grounding / lightning
protection …
Bob
> On Apr 29, 2019, at 2:21 PM, Denny Page wrote:
>
> Thanks Bob, this is in fact what I ended up doing. I bought a pair of the L1
> / L2 / L5 antennas from China, one for rooftop mounting at the new
Thanks Bob, this is in fact what I ended up doing. I bought a pair of the L1 /
L2 / L5 antennas from China, one for rooftop mounting at the new site, and one
for testing. I paired it with a splitter from GPS Networking. 35 feet of RG-213
from the antenna to the splitter, and 3 feet of rg-58
One additional interesting thing which I didn’t anticipate is the effect of
moving from multiple (puck) antennas to a single antenna.
The graph below shows the relationship between two LeoNTP units in the local
network as perceived by chrony. The system clock is synced to the first LeoNTP
News of this GNSS specific amplified splitter dropped into my mailbox today
https://www.sv1afn.com/gps-antenna-splitter.html
Nigel GM8PZR
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Hi
When they say “you have to use *only* the F9 config and commands” they very
much mean it …. except when
the don’t. Sorting that out has taken a while. Getting the survey to re-start
seems a bit backwards. That may be
simple because I’ve been away from uBlox for a while ….
Bob
> On Jan 31,
You will need RINEX v3.x format to take advantage of the F9 multi-GNSS data.
CSRS-PPP seems to be the only online service that takes v3 data. Also they
seem to only handle GPS and GLONASS at the moment.
I have an F9P on order, but Fedex seems to be taking their sweet time (says 2
weeks to
Hi
Indeed, putting a ground plane on a GPS antenna that is not designed
to use one will make it perform worse than it will with one. If the antenna
is a modern one that is designed for mounting on a tripod or a pole, it’s
a good bet it was designed to not have a ground plane backing it up.
A
On Tue, 29 Jan 2019 21:29:20 +0100
Achim Gratz wrote:
> Typically if they already have a ground plane mounted it's between
> 6cm…10cm in diameter (or side length if quadratic). Over that size you
> shouldn't see much effect anymore on the antenna sensitivity pattern,
There is quite a big
I don't know if that Chinese multi-band antenna needs a ground plane/pizza pan.
My antenna mount tripod has one handy, so I am using it.My first tests
were without the pan and I didn't notice any before/after differences but did
not do any extensive testing. The CSRS-PPP position error
On Wed, Jan 30, 2019 at 1:00 PM Bob kb8tq wrote:
> Hi
>
> The thing I’m not quite understanding here - why in the world use an
> antenna that needs
> a ground plane when you can get one that does not need an external ground
> plane?
>
>
What can I say, that antenna was $5.45, locally picked up
Hi
The thing I’m not quite understanding here - why in the world use an antenna
that needs
a ground plane when you can get one that does not need an external ground
plane?
I have three multi band GNSS antennas on the back of the house. They all get
down to
insane error circles (like a mm)
Denny Page via time-nuts writes:
> Thanks Mark. For the cost, this seems like a worthwhile thing to
> try. I don’t think the homeowners association would be too thrilled
> about a pizza pan on a pole so I’ll probably have to do without.
Use a resonant ground plane with four or eight tuned radials
Hi
Wind load is not a good thing when you are putting things way up in the air on
poles. Survival will
be much more likely if you don’t have to attach a great big sail to the antenna
….
Bob
> On Jan 30, 2019, at 11:38 AM, Denny Page via time-nuts
> wrote:
>
> Thanks Mark. For the cost,
Just tell your neighbors that you "cut the cord" and it is a new fangled
miracle "Digital" amplified UHF TV antenna. Any outside TV antenna falls
under the FCC OTARD exceptions, and your homeowners association can't do
a thing about it. :)
John
On 1/30/2019 9:38 AM, Denny Page via time-nuts
On 1/30/19 8:38 AM, Denny Page via time-nuts wrote:
Thanks Mark. For the cost, this seems like a worthwhile thing to try. I don’t
think the homeowners association would be too thrilled about a pizza pan on a
pole so I’ll probably have to do without.
Besides, If I mounted a pizza pan I would
Put a "Bird Feeder" on the side of the house.
Even only seeing less than 1/2 the sky, this is doing OK with just a
TruePosition L1 GPS, always 7-8 sats. I have room for two antennas on the
ground plane, only have one and am using an HP 58515A active splitter.
Hopefully the attachment comes
Thanks Mark. For the cost, this seems like a worthwhile thing to try. I don’t
think the homeowners association would be too thrilled about a pizza pan on a
pole so I’ll probably have to do without.
Besides, If I mounted a pizza pan I would also endure endless teasing from from
my wife who
Hi
Often the “puck” that comes with a demo board is set up to only work when
directly connected to the board. No long cable runs, no splitters, no lightning
protection
to all add a bit of loss here and there. It also is a good bet that whatever is
supplied
“free” with the demo board came from
Hi
Well, the lower cost alternative works fine without any ground plane at all.
That
seems like the winning solution :)
My guess is that they designed it to go on the cab of a truck. That would get
you
to something around 4’ x 6’. As Mark mentions …. no idea what they do or don’t
need for
Hal Murray writes:
> kb8tq-wyfad0z3...@public.gmane.org said:
>> The first one is designed to mount on a ground plane (which is fine if it is
>> going on a truck or airplane).
>
> How big a ground plane do they need? I'm thinking of a sheet of aluminum.
Typically if they already have a ground
Bob kb8tq writes:
> The first one is designed to mount on a ground plane (which is fine if it is
> going
> on a truck or airplane). It also is a bit low in gain for what I *think* the
> F9 is looking
> for.
The only antenna that u-Blox themselves advertise for use with the
(eval) F9P module
kb...@n1k.org said:
> The first one is designed to mount on a ground plane (which is fine if it is
> going on a truck or airplane).
How big a ground plane do they need? I'm thinking of a sheet of aluminum.
--
These are my opinions. I hate spam.
This is the antenna that I am now using. I do have it mounted over an 18"
pizza pan... I don't know if that does any good, it seemed to work fine
without it.
Hi
The first one is designed to mount on a ground plane (which is fine if it is
going
on a truck or airplane). It also is a bit low in gain for what I *think* the F9
is looking
for.
The second one has the right sort of gain, but still is targeted at a ground
plane
(rolling stock)
> On Jan 27, 2019, at 05:28, Bob kb8tq wrote:
>
> With things like the uBlox F9 now out on the market cheap …. I would go with
> an antenna that will do L1 / L2 / L5 and work with everything that it up
> there.
Like these?
I'm currently using one of those sub-$100 Chinese multi-band antennas. It
works quite well. With a L1/L2 survey grade receiver I get position error
ellipses in the 6-10 mm range (amazing considering my horrible
antenna/multipath environment).
Antenna feed is 50 feet of RG6 coax. It feeds a
On 1/27/19 6:24 AM, Bill Slade wrote:
Hi again,
The very best GNSS antennas tend to be based on suspended patch antenna
(air-dielectric) structures because they give the best
bandwidth/radiation efficiency (and hence, noise temperature)
performance. The very best include choke-rings for
Hi
True indeed and for about $10,000 you can get pretty close to “the best”. If you
want to slum it, you can get “pretty good” for about $2,000. If you are truly
after high end performance new is the way to go. Getting the full modern suite
of signals on a used one …. not so much. Even
Hi Denny and list,
Some thoughts from me...worth about what you paid for them considering
my Time-Nuts membership card was revoked the week before last for
heresy, hahaha! ;)
PCTEL GNSS1-TMG-40N
(https://www.pctel.com/antenna-product/global-gnss-timing-antenna-gnss1-tmg-40n/)
I've got
Hi again,
The very best GNSS antennas tend to be based on suspended patch antenna
(air-dielectric) structures because they give the best
bandwidth/radiation efficiency (and hence, noise temperature)
performance. The very best include choke-rings for multipath
suppression (Dorne-Margolin &
Hi
With things like the uBlox F9 now out on the market cheap …. I would go with
an antenna that will do L1 / L2 / L5 and work with everything that it up there.
You still are in the “under $100” range (delivered) for new product from China.
It’s a good bet that the guts of all of them are made
Hello Denny,
Things to keep in mind:
1. To keep noise performance, LNA gain at the antenna should be at least 10
dB above total losses in antenna cable & distribution network. 13-16 dB above
is better. Something like this would be more than suitable for a 30 ft run:
For a 30-35 outdoor cable run go with as big a coax as you can afford. At these
frequencies attenuation becomes even more critical than say an HF application.
There are several online attenuation calculators for various cable
configurations that you might want to play around with:
Hi all,
I’m looking for recommendations on an antenna / splitter configuration. I
currently have six GPS/GLONASS/Galileo timing devices, each with it’s own puck
antenna in a window. I have an opportunity to move to a (single) roof top
antenna, with a splitter to feed the individual devices,
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