Empathy List Archives

DP

Denny Page

Mon, Apr 29, 2019 6:21 PM

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 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well.

I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :)

On Jan 27, 2019, at 05:28, Bob kb8tq kb8tq@n1k.org wrote:

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 there. It’s also a good bet
that they all are ceramic slab style designs.

Bob

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 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well. I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :) > On Jan 27, 2019, at 05:28, Bob kb8tq <kb8tq@n1k.org> wrote: > > 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 there. It’s also a good bet > that they all are ceramic slab style designs. > > Bob >

DP

Denny Page

Mon, Apr 29, 2019 7:09 PM

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 unit, and the graph represents chrony’s view of the clock offset for the second LeoNTP unit. 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. Other timing units in the local network show a similar result.

I really didn’t expect such a dramatic change.

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 unit, and the graph represents chrony’s view of the clock offset for the second LeoNTP unit. 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. Other timing units in the local network show a similar result. I really didn’t expect such a dramatic change.

BK

Bob kb8tq

Mon, Apr 29, 2019 9:23 PM

Hi

Looks like that should work. Don’t forget about grounding / lightning protection …

Bob

On Apr 29, 2019, at 2:21 PM, Denny Page denny@cococafe.com 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 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 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well.

I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :)

<outside.jpeg>
<inside.jpeg>

On Jan 27, 2019, at 05:28, Bob kb8tq <kb8tq@n1k.org mailto:kb8tq@n1k.org> wrote:

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 there. It’s also a good bet
that they all are ceramic slab style designs.

Bob

Hi Looks like that should work. Don’t forget about grounding / lightning protection … Bob > On Apr 29, 2019, at 2:21 PM, Denny Page <denny@cococafe.com> 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 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 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well. > > I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :) > > > <outside.jpeg> > <inside.jpeg> > > > >> On Jan 27, 2019, at 05:28, Bob kb8tq <kb8tq@n1k.org <mailto:kb8tq@n1k.org>> wrote: >> >> 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 there. It’s also a good bet >> that they all are ceramic slab style designs. >> >> Bob >> >

DP

Denny Page

Mon, Apr 29, 2019 10:36 PM

[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 antenna to the splitter, and 3 feet of rg-58 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well.

I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :)

On Jan 27, 2019, at 05:28, Bob kb8tq kb8tq@n1k.org wrote:

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 there. It’s also a good bet
that they all are ceramic slab style designs.

Bob

[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 antenna to the splitter, and 3 feet of rg-58 from splitter to the devices. The one I’m using for testing is sitting on my desk near a window… so far it’s been working well. I’ve included a couple of pics of the mounting below. This is what can happen when a contractor enjoys a good challenge. :) > On Jan 27, 2019, at 05:28, Bob kb8tq <kb8tq@n1k.org> wrote: > > 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 there. It’s also a good bet > that they all are ceramic slab style designs. > > Bob >

DP

Denny Page

Mon, Apr 29, 2019 10:36 PM

[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 system clock is synced to the first LeoNTP unit, and the graph represents chrony’s view of the clock offset for the second LeoNTP unit. 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. Other timing units in the local network show a similar result.

I really didn’t expect such a dramatic change.

[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 system clock is synced to the first LeoNTP unit, and the graph represents chrony’s view of the clock offset for the second LeoNTP unit. 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. Other timing units in the local network show a similar result. I really didn’t expect such a dramatic change.

DP

Denny Page

Tue, Apr 30, 2019 12:10 AM

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

Thank you to Tom and John for trying to help!

Denny

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 Thank you to Tom and John for trying to help! Denny

DW

Dana Whitlow

Tue, Apr 30, 2019 1:18 AM

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 locations more than anything else. If this is what's
going on,
you've made very strong case for outdoor antennas for GPS timing.

Also, it's possible that the two receivers with their antennas in such close
proximity might have been interfering with each other.

Dana

On Mon, Apr 29, 2019 at 8:07 PM Denny Page via time-nuts <
time-nuts@lists.febo.com> wrote:

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

Thank you to Tom and John for trying to help!

Denny

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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 locations more than anything else. If this is what's going on, you've made very strong case for outdoor antennas for GPS timing. Also, it's possible that the two receivers with their antennas in such close proximity might have been interfering with each other. Dana On Mon, Apr 29, 2019 at 8:07 PM Denny Page via time-nuts < time-nuts@lists.febo.com> wrote: > 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 > > Thank you to Tom and John for trying to help! > > Denny > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. >

DP

Denny Page

Tue, Apr 30, 2019 3:32 AM

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 different groups—2 groups of 3 antennas separated by 4 inches, and 1 antenna off by itself. However, all showed an increased “closeness” in tracking when moving to the common antenna. It’s not exactly a controlled test, but surprising nonetheless. Just out of curiosity, I may do a more controlled comparison once I’m done with the current testing.

Denny

On Apr 29, 2019, at 18:18, Dana Whitlow k8yumdoober@gmail.com wrote:

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 locations more than anything else. If this is what's
going on,
you've made very strong case for outdoor antennas for GPS timing.

Also, it's possible that the two receivers with their antennas in such close
proximity might have been interfering with each other.

Dana

On Mon, Apr 29, 2019 at 8:07 PM Denny Page via time-nuts <
time-nuts@lists.febo.com> wrote:

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

Thank you to Tom and John for trying to help!

Denny

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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 different groups—2 groups of 3 antennas separated by 4 inches, and 1 antenna off by itself. However, all showed an increased “closeness” in tracking when moving to the common antenna. It’s not exactly a controlled test, but surprising nonetheless. Just out of curiosity, I may do a more controlled comparison once I’m done with the current testing. Denny > On Apr 29, 2019, at 18:18, Dana Whitlow <k8yumdoober@gmail.com> wrote: > > 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 locations more than anything else. If this is what's > going on, > you've made very strong case for outdoor antennas for GPS timing. > > Also, it's possible that the two receivers with their antennas in such close > proximity might have been interfering with each other. > > Dana > > > On Mon, Apr 29, 2019 at 8:07 PM Denny Page via time-nuts < > time-nuts@lists.febo.com> wrote: > >> 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 >> >> Thank you to Tom and John for trying to help! >> >> Denny >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

DJ

David J Taylor

Tue, Apr 30, 2019 7:34 AM

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 locations more than anything else. If this is
what's going on, you've made very strong case for outdoor antennas for GPS
timing.

Also, it's possible that the two receivers with their antennas in such close
proximity might have been interfering with each other.

Dana

---====

Agreed with Dana's comments on the antennas. If indoors the signal strength
would be much less. Did you have a ground plane for the puck antennas? I
went through a couple of iterations:

https://www.satsignal.eu/ntp/2013-03-31-1226-32-GPS-antenna-farm.jpg

https://www.satsignal.eu/ntp/2019-01-08-1330-23b-GPS-antenna-farm.jpg

and I have a simple outdoor L1 antenna & splitter too.

Cheers,
David

SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

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 locations more than anything else. If this is what's going on, you've made very strong case for outdoor antennas for GPS timing. Also, it's possible that the two receivers with their antennas in such close proximity might have been interfering with each other. Dana ===================================== Agreed with Dana's comments on the antennas. If indoors the signal strength would be much less. Did you have a ground plane for the puck antennas? I went through a couple of iterations: https://www.satsignal.eu/ntp/2013-03-31-1226-32-GPS-antenna-farm.jpg https://www.satsignal.eu/ntp/2019-01-08-1330-23b-GPS-antenna-farm.jpg and I have a simple outdoor L1 antenna & splitter too. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-taylor@blueyonder.co.uk Twitter: @gm8arv

BK

Bob kb8tq

Tue, Apr 30, 2019 11:30 AM

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

On Apr 30, 2019, at 3:34 AM, David J Taylor via time-nuts time-nuts@lists.febo.com wrote:

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 locations more than anything else. If this is what's going on, you've made very strong case for outdoor antennas for GPS timing.

Also, it's possible that the two receivers with their antennas in such close proximity might have been interfering with each other.

Dana

---====

Agreed with Dana's comments on the antennas. If indoors the signal strength would be much less. Did you have a ground plane for the puck antennas? I went through a couple of iterations:

https://www.satsignal.eu/ntp/2013-03-31-1226-32-GPS-antenna-farm.jpg

https://www.satsignal.eu/ntp/2019-01-08-1330-23b-GPS-antenna-farm.jpg

and I have a simple outdoor L1 antenna & splitter too.

Cheers,
David

SatSignal Software - Quality software for you
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

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 > On Apr 30, 2019, at 3:34 AM, David J Taylor via time-nuts <time-nuts@lists.febo.com> wrote: > > 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 locations more than anything else. If this is what's going on, you've made very strong case for outdoor antennas for GPS timing. > > Also, it's possible that the two receivers with their antennas in such close proximity might have been interfering with each other. > > Dana > ===================================== > > Agreed with Dana's comments on the antennas. If indoors the signal strength would be much less. Did you have a ground plane for the puck antennas? I went through a couple of iterations: > > https://www.satsignal.eu/ntp/2013-03-31-1226-32-GPS-antenna-farm.jpg > > https://www.satsignal.eu/ntp/2019-01-08-1330-23b-GPS-antenna-farm.jpg > > and I have a simple outdoor L1 antenna & splitter too. > > Cheers, > David > -- > SatSignal Software - Quality software for you > Web: http://www.satsignal.eu > Email: david-taylor@blueyonder.co.uk > Twitter: @gm8arv > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

time-nuts@lists.febo.com

Rooftop antenna and splitter

Cheers, David

Cheers, David

Cheers,
David

Cheers,
David