GPS antenna selection
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
-
What are the key specifications which need to
be verified before buying a GPS antenna? -
How can they be compared based on incomplete
specifications? -
Is a place on the roof or in the garden worth
the trouble over the covered balcony? -
Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1] http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
Do you have a picture of the balcony?
----- Original Message -----
From: "Herbert Poetzl" herbert@13thfloor.at
To: time-nuts@febo.com
Sent: Thursday, August 04, 2016 5:29 PM
Subject: [time-nuts] GPS antenna selection
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
-
What are the key specifications which need to
be verified before buying a GPS antenna? -
How can they be compared based on incomplete
specifications? -
Is a place on the roof or in the garden worth
the trouble over the covered balcony? -
Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
[2]
http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
[3]
http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
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To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
On Aug 4, 2016, at 5:29 PM, Herbert Poetzl herbert@13thfloor.at wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
That’s the spec on the interference rejection filter. Tighter is better
as long as it still passes the desired signal(s).
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The better ones will have a TNC connector on them
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
- What are the key specifications which need to
be verified before buying a GPS antenna?
You want one that is designed for permanent outdoor use. That eliminates the $10
car mounts. These days, I’d get one that does both GPS and GLONASS
- How can they be compared based on incomplete
specifications?
They can’t. It’s just luck. The ones you see for about $40 and up that are designed
for mast mounting are usually pretty good.
- Is a place on the roof or in the garden worth
the trouble over the covered balcony?
The real question is how much of a sky view you get. Ideally you would like a clear view
of the sky from about NE clear around to NW (270 degrees). You also would like to be
able to “see” down to within 10 degrees of the horizon over that range. The segment from
E to W (180 degrees) is pretty important. Being able to see to within 30 degrees of the
horizon is also pretty important.
- Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Some receivers put out +12V, most antennas don’t like +12 and want +5. Some modern
antennas will only handle +3.3V.
If you have a long run to the antenna, feed line loss is what matters. To some degree
you can cope with this by buying an antenna that has a higher gain amp in it. They
range from about 21 db to about 50 db. You also don’t want to over drive your receiver
so just getting the 50 db version is not a perfect solution.
Grounding the antenna is always a good idea. A surge suppressor in the line could save
you some real cost if there is a lightning strike. I don’t know about Austria, but here in
the US, both are required.
Bob
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1] http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi Herbert,
just look the loss of the cable at 1500 MHz, and you will start to cry
at 1500MHz tha cable will have cca 30dB for a 30meter long
piece....basically that RG174 looks very nice with that small antenna
but that is the only positive aspect. Meinberg in Germany has one
up/down converting system, which makes it possible to go more than 50 meter.
On the other hand if you could stay on the balcony and use the cable
which came with the antenna, 2m to 3 meter, you could have a good
working system, but with 15m RG174 is asking to much. For 1500 MHz BNC
is not the best solution,
73
KJ6UHN
Alex
P.S.: wo ist diese "Austrian countryside"
On 8/4/2016 2:29 PM, Herbert Poetzl wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
-
What are the key specifications which need to
be verified before buying a GPS antenna? -
How can they be compared based on incomplete
specifications? -
Is a place on the roof or in the garden worth
the trouble over the covered balcony? -
Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1] http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7690 / Virus Database: 4627/12745 - Release Date: 08/04/16
On Thu, Aug 04, 2016 at 06:26:28PM -0400, Bob Camp wrote:
Hi
Hey Bob!
On Aug 4, 2016, at 5:29 PM, Herbert Poetzl herbert@13thfloor.at wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
That’s the spec on the interference rejection filter.
Tighter is better as long as it still passes the
desired signal(s).
Understood!
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The better ones will have a TNC connector on them
Hmm, I had to google TNC (Threaded Neill-Concelman).
Is it worth the trouble in the < 2GHz range?
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
- What are the key specifications which need to
be verified before buying a GPS antenna?
You want one that is designed for permanent outdoor
use.
That eliminates the $10 car mounts.
Even under somewhat protected conditions like on the
covered balcony?
These days, I’d get one that does both GPS and GLONASS
Makes sense.
- How can they be compared based on incomplete
specifications?
They can’t. It’s just luck. The ones you see for
about $40 and up that are designed for mast mounting
are usually pretty good.
Okay, thanks!
- Is a place on the roof or in the garden worth
the trouble over the covered balcony?
The real question is how much of a sky view you get.
Ideally you would like a clear view of the sky from
about NE clear around to NW (270 degrees).
That would opt for the balcony, as it faces north
and extends the slanted roof, so basically clear
view from NE to NW down to the horizon.
You also would like to be able to “see” down to within
10 degrees of the horizon over that range.
The segment from E to W (180 degrees) is pretty
important.
Being able to see to within 30 degrees of the horizon
is also pretty important.
- Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Some receivers put out +12V, most antennas don’t like
+12 and want +5.
Some modern antennas will only handle +3.3V.
If you have a long run to the antenna, feed line loss
is what matters.
To some degree you can cope with this by buying an
antenna that has a higher gain amp in it.
They range from about 21 db to about 50 db.
You also don’t want to over drive your receiver so
just getting the 50 db version is not a perfect
solution.
Understood! Is there some rule of thumb at what
cable lengths which amplifier gain is best suited?
Grounding the antenna is always a good idea.
A surge suppressor in the line could save you some
real cost if there is a lightning strike.
I did a quick search for SMA/BNC/TNC based surge
protectors and not much did come up, any suggestions
what to use there?
I don’t know about Austria, but here in the US,
both are required.
Outside definitely, "inside" I'm not sure, but it
won't hurt to have additional protection for the
receiver(s).
Thanks a bunch,
Herbert
Bob
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
On Aug 4, 2016, at 7:26 PM, Herbert Poetzl herbert@13thfloor.at wrote:
On Thu, Aug 04, 2016 at 06:26:28PM -0400, Bob Camp wrote:
Hi
Hey Bob!
On Aug 4, 2016, at 5:29 PM, Herbert Poetzl herbert@13thfloor.at wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
That’s the spec on the interference rejection filter.
Tighter is better as long as it still passes the
desired signal(s).
Understood!
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The better ones will have a TNC connector on them
Hmm, I had to google TNC (Threaded Neill-Concelman).
Is it worth the trouble in the < 2GHz range?
It threads on rather than latches on like a BNC. That makes it
more water tight in the outdoor environment.
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
- What are the key specifications which need to
be verified before buying a GPS antenna?
You want one that is designed for permanent outdoor
use.
That eliminates the $10 car mounts.
Even under somewhat protected conditions like on the
covered balcony?
You still have fog / condensation / humidity and the other sources
of moisture. So not quite so important, but we rule out the balcony below.
These days, I’d get one that does both GPS and GLONASS
Makes sense.
- How can they be compared based on incomplete
specifications?
They can’t. It’s just luck. The ones you see for
about $40 and up that are designed for mast mounting
are usually pretty good.
Okay, thanks!
- Is a place on the roof or in the garden worth
the trouble over the covered balcony?
The real question is how much of a sky view you get.
Ideally you would like a clear view of the sky from
about NE clear around to NW (270 degrees).
That would opt for the balcony, as it faces north
and extends the slanted roof, so basically clear
view from NE to NW down to the horizon.
It needs to face south and have a clear view over a 270 degree arc.
If it faces north …. not going to work very well at all.
You also would like to be able to “see” down to within
10 degrees of the horizon over that range.
The segment from E to W (180 degrees) is pretty
important.
Being able to see to within 30 degrees of the horizon
is also pretty important.
- Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Some receivers put out +12V, most antennas don’t like
+12 and want +5.
Some modern antennas will only handle +3.3V.
If you have a long run to the antenna, feed line loss
is what matters.
To some degree you can cope with this by buying an
antenna that has a higher gain amp in it.
They range from about 21 db to about 50 db.
You also don’t want to over drive your receiver so
just getting the 50 db version is not a perfect
solution.
Understood! Is there some rule of thumb at what
cable lengths which amplifier gain is best suited?
The more money you pay for the cable the lower it’s loss. For $10 a meter you
get a lower loss cable than $1 a meter or $0.10 a meter. Figure that anything over
about a 30 meter run will require either a high gain antenna or some money invested
in LMR-400 cable.
Grounding the antenna is always a good idea.
A surge suppressor in the line could save you some
real cost if there is a lightning strike.
I did a quick search for SMA/BNC/TNC based surge
protectors and not much did come up, any suggestions
what to use there?
There are a lot of them on eBay. Many of them have N connectors on them.
I don’t know about Austria, but here in the US,
both are required.
Outside definitely, "inside" I'm not sure, but it
won't hurt to have additional protection for the
receiver(s).
It is a good bet that the antenna will be outside. I’d plan it that way.
Bob
Thanks a bunch,
Herbert
Bob
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
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What matters more than anything else is how good is the view of the sky.
Next You want one that will last basically "forever" outdoors. The
best kind have a plastic radome over a metal base. The base has pipe
threads for mounting on a standard 3/4" galvanized plumbing pipe. The
coax wires goes down this pie and never sees the light of day or rain
water either
The shape of the dome does matter, you want the pointed kind that
birds can not perch on. If the top is flat od even hemispherical it
will get covered with bird poop.
When I put mine up on the roof most of the work was done in the attic.
I drilled a 1 inch hole and pushed the mast (1" pipe" up through the
hole then secured it with U-straps to a rafter and joist and tugged on
it hard from all directions to make sure it would not move. Put a
level on it first and check for vertical. It is no more work to use
a longer pipe than a short one so go up 3 feet above the roof line.
Then while ion top of the roof just flash the hole to prevent a leak
and drop the coax cable down the pip and screw on the antenna to the
mast.
You local building code likely wants you to ground the antenna mast
lust like you would with an old TV antenna. It is a good idea to
prevent lightening damage to the house.
With the radome typically sealed by o-ring to the base plate and the
lead wire hidden inside a galvanized pipe there is nothing to degrade
over time. It should be maintenance free for decades or until hit by
lightening
Al the other stuff about what kind of coax to buy and what connectors
are best and so on are "in the noise" the important stuff is (1) view
of the sky and (2) build so you will never in your lifetime have to
fix it
If you must place it near a balcony or window make sure it faces south
as that is where the satellites are, they don't orbit over the poles.
On Aug 4, 2016, at 2:29 PM, Herbert Poetzl herbert@13thfloor.at wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
-
What are the key specifications which need to
be verified before buying a GPS antenna? -
How can they be compared based on incomplete
specifications? -
Is a place on the roof or in the garden worth
the trouble over the covered balcony? -
Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1] http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-Antenna-connector/dp/B00D8WAVTC
[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
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I just wrote that the type of cable hardly matters. I did not think anyone
would try to use RG174. That is for 1 foot long jumper cables and
oscilloscope probes at most. If cost is an issue the 75ohm cable TV wire
is cheap and works better then that tiny sized rg175.
There is no need to buy the high priced stuff as you can buy an antenna
with 30db gain and that makes up for the loss in any reasonable cable.
On Thu, Aug 4, 2016 at 3:32 PM, Alex Pummer alex@pcscons.com wrote:
Hi Herbert,
just look the loss of the cable at 1500 MHz, and you will start to cry at
1500MHz tha cable will have cca 30dB for a 30meter long piece....basically
that RG174 looks very nice with that small antenna but that is the only
positive aspect. Meinberg in Germany has one up/down converting system,
which makes it possible to go more than 50 meter.
On the other hand if you could stay on the balcony and use the cable which
came with the antenna, 2m to 3 meter, you could have a good working
system, but with 15m RG174 is asking to much. For 1500 MHz BNC is not the
best solution,
73
KJ6UHN
Alex
P.S.: wo ist diese "Austrian countryside"
On 8/4/2016 2:29 PM, Herbert Poetzl wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
Setting:
I'm living in a three storey house with a sloped
roof, a covered balcony and a larger garden with
huge trees on the Austrian countryside (Europe).
I've walked around with my smartphone (older one)
and I get a GPS position fix within 35s in the
garden (nine satellites shown), within 100s on
the balcony (also nine satellites), and not a
single satellite can be seen indoors.
The obvious choice would be to put the antenna on
top in the middle of the slanted roof for a perfect
sky view, but this brings a number of problems as
the roof is very hard to reach and quite high.
I have my 'lab' at the floor where the balcony is,
so I'm considering putting an antenna there and
run about 5-15m of coax cable to the GPS receiver.
The advantage there is that the antenna would be
somewhat protected (it still gets very hot during
summer and very cold during winter, but no rain
and no snow) and easy to reach for maintenance.
The third alternative would be to put the antenna
somewhere in the garden and have a rather long
cable running to the house and up to my lab.
Antennae:
Looking on eBay and Amazon shows a huge pricerange
for active GPS antennae with and without cable.
It seems to start at about 10 bucks with rather
small black boxes [1] designed for cars, probably
containing a 25x25 ceramic GPS antenna and an
amplifier, progresses over very interesting out-
door constructions for boats and whatnot [2] in
the 20-100 bucks range and finally tops with high
end devices [3] way above 100 bucks.
The information about the cheap devices is usually
very scarce, but typically boils down to:
1575.42 +/- 5MHz
24-28dB LNA Gain with 10-25mA at (3-5V)
7dB f0 +/- 20MHz
20dB f0 +/- 50MHz
30dB f0 +/- 100MHz
They seem to use RG174 and come with SMA as well
as BNC connectors (and a number of others as well).
The mid range devices seem to use larger antennae
with smaller tolerances (+/- 1MHz) and larger
voltage ranges for the amplifier (3-13V).
Questions:
-
What are the key specifications which need to
be verified before buying a GPS antenna? -
How can they be compared based on incomplete
specifications? -
Is a place on the roof or in the garden worth
the trouble over the covered balcony? -
Are there any typical pit-falls or general
tips and tricks regarding mounting and cable
connection to the receiver?
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1] http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle
-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/
dp/B00LXRQY9A
[2] http://www.ebay.com/itm/Standard-Horizon-XUCMP0014-GPS-
Antenna-f-CP150-CP160-CP170/331364914004
https://www.amazon.com/Garmin-010-12017-00-GPS-
GLONASS-Antenna/dp/B00EVT2HSE
https://www.amazon.com/SUNDELY®-External-Marine-
Antenna-connector/dp/B00D8WAVTC
[3] http://www.ebay.com/itm/NEW-FURUNO-GPA018-Gps-dgps-Antenna-/
182223355414
https://www.amazon.com/Garmin-nmea-2000-orders-over/dp/B0089DU96A
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Version: 2016.0.7690 / Virus Database: 4627/12745 - Release Date: 08/04/16
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Chris Albertson
Redondo Beach, California
On Thu, 04 Aug 2016 23:29:06 +0200, Herbert Poetzl wrote:
Dear fellow time-nuts!
I'm currently investigating my options regarding GPS antennae (of course
for time related purposes)
and I'm really confused by the variety they come in ... (my apologies in
advance for the long post).
Setting:
I'm living in a three storey house with a sloped roof, a covered balcony
and a larger garden with huge trees on the Austrian countryside
(Europe).
I'm using this type (26dB, N Connector) on my balcony (South).
It's mounted on a 1m waterpipe, that is "stripped" to the balcony fence.
I initially bought a 40dB , but had to change to 26dB , due to too much
gain.
www.ebay.com/itm/PCTEL-GPS-TMG-26N-26-dB-Internal-Amplifier-Timing-
Reference-Antenna-/232037804675
www.ebay.com/itm/Lucent-Datum-KS24019L112C-GPS-26dB-5V-Antenna-Telecom-
Timing-N-Conn-Andrews-NEW-/361510967153
I use a Tbolt, that have 75ohm impedance , and am using about 25m quad
shielded 75 ohm , quality sattelite cable from the balcony to the Tbolt.
I'm using a N-->F adapter at the antenna end, that makes it super easy to
make a diy F-->F connector cable.
I now have installed a quad active antenna splitter (50ohm) , using the
same 75ohm cable , and a F-->N adapter at the splitter end. And see no
noticable problems using 75ohm cable there.
CFO
Denmark
Dear fellow time-nuts!
I'm currently investigating my options regarding
GPS antennae (of course for time related purposes)
and I'm really confused by the variety they come
in ... (my apologies in advance for the long post).
[]
Many thanks in advance and my apologies again for
the rather lengthy post. Please feel free to point
me to previous discussion regarding this topic.
All the best,
Herbert
[1]
http://www.ebay.com/itm/99-Good-GPS-Antenna-SMA-Screw-Needle-10m-Super-Signal-Navigation-DVD-Antenna-/171802461614
https://www.amazon.com/Waterproof-Active-Antenna-28dB-Gain/dp/B00LXRQY9A
Herbert,
Based on practical experiences here the antenna [1] on the balcony (outside)
would be more than adequate for a modern receiver. Receivers from 10-15
years back are less sensitive and may require an antenna more like [2] (but
that has BNC connector).
I would try the cheaper antenna first, and it's no great loss if you have to
abandon it later.
I don't believe that you mentioned what receiver this was for.
Cheers,
David
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv