Too many GPS puck antennas

[Charles Longley]

I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

[JS[_5_]]

On Friday, January 10, 2020 at 6:22:22 PM UTC-8, Charles Longley wrote:
> I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

I've been using a MECA divider for several years now.
Besides the panel being less crowded, GPS satellites aquire much faster.
Don't use DC blockers. Use a 12v GPS antenna to feed the divider. This way if your primary device fails, you don't lose all of them.
Search for GPS divider in the subject, links were posted on a previous thread.
Jim

[Richard Pfiffner[_2_]]

On Friday, January 10, 2020 at 6:22:22 PM UTC-8, Charles Longley wrote:
> I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

Charles,

Cables and combiners on the bottom of this page.

http://www.craggyaero.com/antennas.htm

Richard
www.craggyaero.com

[[email protected]]

On Friday, January 10, 2020 at 9:22:22 PM UTC-5, Charles Longley wrote:
> I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

Too many puck GPS antennas too close together will lead to interference and poor function.
I remember reading somewhere that these puck antennas must be 30 inches apart to help reduce the possibility of such interference.

[Dan Marotta]

I put a couple on my canopy rails.Â* Most (mine, at least) GPS pucks have
a magnetic base so I glued small steel washers to the glare shield and
slapped the pucks in place.Â* No worries when jettisoning the canopy.

On 1/10/2020 7:22 PM, Charles Longley wrote:
> I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

--
Dan, 5J

[Charles Longley]

I like your idea best Richard. I’ll give you a call next week.

[Eric Greenwell[_4_]]

wrote on 1/11/2020 6:07 AM:
> On Friday, January 10, 2020 at 9:22:22 PM UTC-5, Charles Longley wrote:
>> I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?
>
> Too many puck GPS antennas too close together will lead to interference and poor function.
> I remember reading somewhere that these puck antennas must be 30 inches apart to help reduce the possibility of such interference.
>
I'm sure the recommendation is much less than 30". Practically speaking, I've 3
antennas in a triangle with 10" sides for 5 years, no apparent problems. Counting
the iPhone mounted near the panel, it's really 4 antennas. My experience is the
norm, I think.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[[email protected][_2_]]

What brand/model 12v GPS antenna is being used, reasons?

R

[JS[_5_]]

On Saturday, January 11, 2020 at 9:49:32 AM UTC-8, wrote:
> What brand/model 12v GPS antenna is being used, reasons?
>
> R

Linx Antenna Factor
ANT-GPS-SH-SMA (with SMA connector)
ANT-GPS-SH-MCX (with MCX connector)
ANT-GPS-SH-MMX (with MMCX connector)

Each GPS engine provides phantom power, and the voltage from each is added. If you use a standard puck the voltage from 2 or 3 engines will be too high.
The Linx has higher gain with higher phantom voltage (up to 12v).
System Gain: 28dB (typ. includes 4dB
cable & filter loss)
Noise Figure: <1.8dB @ fo, 2dB max.
Input Voltage: +2.5VDC to +12VDC
Jim

[Eric Greenwell[_4_]]

wrote on 1/11/2020 9:49 AM:
> What brand/model 12v GPS antenna is being used, reasons?

The ones supplied with Powerflarm core, Cambridge 302, and ClearNav. Later, I
removed the 302 and put in a Butterfly vario, using it's supplied GPS antenna.
Everything seemed to work the same.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Steve Koerner]

This has all been discussed here before. It's a bunch of over-conservative silliness about puck spacing. I actually did testing with different pucks touching each other and they all worked fine. It's better to use the puck supplied with the individual instrument as that introduces less opportunity for something to go wrong. And, if something does go wrong, lesser permutations as to cause.

[JS[_5_]]

On Saturday, January 11, 2020 at 12:34:19 PM UTC-8, Eric Greenwell wrote:
> wrote on 1/11/2020 9:49 AM:
> > What brand/model 12v GPS antenna is being used, reasons?
>
> The ones supplied with Powerflarm core, Cambridge 302, and ClearNav. Later, I
> removed the 302 and put in a Butterfly vario, using it's supplied GPS antenna.
> Everything seemed to work the same.
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

The antennas included with glider instruments aren't good to 12v. Give them a try at 9-12v and report how long they last.
Jim

[Richard Pfiffner[_2_]]

On Saturday, January 11, 2020 at 12:31:14 PM UTC-8, JS wrote:
> On Saturday, January 11, 2020 at 9:49:32 AM UTC-8, wrote:
> > What brand/model 12v GPS antenna is being used, reasons?
> >
> > R
>
> Linx Antenna Factor
> ANT-GPS-SH-SMA (with SMA connector)
> ANT-GPS-SH-MCX (with MCX connector)
> ANT-GPS-SH-MMX (with MMCX connector)
>
> Each GPS engine provides phantom power, and the voltage from each is added. If you use a standard puck the voltage from 2 or 3 engines will be too high.
> The Linx has higher gain with higher phantom voltage (up to 12v).
> System Gain: 28dB (typ. includes 4dB
> cable & filter loss)
> Noise Figure: <1.8dB @ fo, 2dB max.
> Input Voltage: +2.5VDC to +12VDC
> Jim

Dear customer,

Linx Technologies is announcing the end-of-life of the ANT-GPS-SH-SMA, ANT-GPS-SH-MCX and ANT-GPS-SH-MMX Series of antennas, and the launch of the SH2 Series GPS antennas.Key components critical to the design of the SH Series antennas have been discontinued by the IC manufacturer.

SH2 Series are DC 5V


Richard

[Eric Greenwell[_4_]]

JS wrote on 1/11/2020 2:03 PM:
> On Saturday, January 11, 2020 at 12:34:19 PM UTC-8, Eric Greenwell wrote:
>> wrote on 1/11/2020 9:49 AM:
>>> What brand/model 12v GPS antenna is being used, reasons?
>>
>> The ones supplied with Powerflarm core, Cambridge 302, and ClearNav. Later, I
>> removed the 302 and put in a Butterfly vario, using it's supplied GPS antenna.
>> Everything seemed to work the same.
>>
>> --
>> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
>> - "A Guide to Self-Launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>
> The antennas included with glider instruments aren't good to 12v. Give them a try at 9-12v and report how long they last.

I just connect them to the instrument that was in the same box. I was puzzled
about the assumption they were 12 volt antennas; don't have a clue, either.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Delta8]

On Friday, January 10, 2020 at 9:22:22 PM UTC-5, Charles Longley wrote:
I just started pimping out my ASW20. I am putting in a LXNAV S100, FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I haven’t even figured out where to put the FLARM antennas yet! Does anyone have a good solution?

Too many puck GPS antennas too close together will lead to interference and poor function.
I remember reading somewhere that these puck antennas must be 30 inches apart to help reduce the possibility of such interference.

What about compass interference with all those magnets and metal ?
I have one that I moved around the compass but seemed to not affect it .

[Craig Funston[_3_]]

On Saturday, January 11, 2020 at 5:43:09 PM UTC-8, Delta8 wrote:
> ;1007977 Wrote:
> > On Friday, January 10, 2020 at 9:22:22 PM UTC-5, Charles Longley
> > wrote:-
> > I just started pimping out my ASW20. I am putting in a LXNAV S100,
> > FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I
> > haven’t even figured out where to put the FLARM antennas yet! Does
> > anyone have a good solution?-
> >
> > Too many puck GPS antennas too close together will lead to interference
> > and poor function.
> > I remember reading somewhere that these puck antennas must be 30 inches
> > apart to help reduce the possibility of such interference.
>
> What about compass interference with all those magnets and metal ?
> I have one that I moved around the compass but seemed to not affect it
>
>
>
>
>
> --
> Delta8

Compass? We don't need no stinkin compass. ;-)

7Q

[Richard Pfiffner[_2_]]

Eric,

They are not 12V antennas. Most if not all state of the art flight computer GPSs feed the antennas with 3v to 5v.

Richard

[Charles Longley]

Pfft compass what’s that? Look out the canopy.

[Eric Greenwell[_4_]]

Charles Longley wrote on 1/11/2020 6:59 PM:
> Pfft compass what’s that? Look out the canopy.
>
Not a good option in Kansas! You are spoiled by flying where there are mountains
to guide you. In Kansas, look at the GPS track when you want to know direction. Or
pull out your iPhone, and use the compass app.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Richard Frawley]

You can feed the S100 with flarm data which has GPS data

[Darryl Ramm]

On Sunday, January 12, 2020 at 1:31:26 AM UTC-8, Richard Frawley wrote:
> You can feed the S100 with flarm data which has GPS data

This came up elsewhere, and other folks suggested you could not switch the S100 off the internal GPS for basic navigation data.

Do you know for sure the S100 can use that FLARM GPS data for navigation? If so is there any way to select which GPS source is used? The manual seems to not mention this or clarify the GPS source being used. If the connection of a FLARM always have to use the external FLARM GPS that might raise concerns you are not navigating from the exact GPS that is driving the S100 flight recorder (so you are not necessarily seeing exactly the same data... or maybe not noticing any problems). This is a S100 specific question, clearly the S80 etc. use the external GPS data for navigation.

[Charles Longley]

I’ll give it at try this week and report back. Some of my experienced friends don’t think it’ll work with an S100.

[Dan Marotta]

Play around with positioning.Â* If you want to try the glued on washers
with magnetic antennae, try installing them as far back or as far
forward on the canopy rails as you can.Â* My Stemme is very wide so my
pucks are far away from the panel.



On 1/11/2020 5:48 PM, Delta8 wrote:
> ;1007977 Wrote:
>> On Friday, January 10, 2020 at 9:22:22 PM UTC-5, Charles Longley
>> wrote:-
>> I just started pimping out my ASW20. I am putting in a LXNAV S100,
>> FLARM and an ADS-B Trig transponder. Thant’s three puck antennas and I
>> haven’t even figured out where to put the FLARM antennas yet! Does
>> anyone have a good solution?-
>>
>> Too many puck GPS antennas too close together will lead to interference
>> and poor function.
>> I remember reading somewhere that these puck antennas must be 30 inches
>> apart to help reduce the possibility of such interference.
> What about compass interference with all those magnets and metal ?
> I have one that I moved around the compass but seemed to not affect it
> .
>
>
>
>

--
Dan, 5J

[Dan Marotta]

....or just look at the section lines on then ground.Â* If the sun is
shining, it's pretty easy to guess the cardinal directions.

On 1/11/2020 8:58 PM, Eric Greenwell wrote:
> Charles Longley wrote on 1/11/2020 6:59 PM:
>> Pfft compass what’s that? Look out the canopy.
>>
> Not a good option in Kansas! You are spoiled by flying where there are
> mountains to guide you. In Kansas, look at the GPS track when you want
> to know direction. Or pull out your iPhone, and use the compass app.
>

--
Dan, 5J

[2G]

On Sunday, January 12, 2020 at 8:27:19 AM UTC-8, Dan Marotta wrote:
> ...or just look at the section lines on then ground.Â* If the sun is
> shining, it's pretty easy to guess the cardinal directions.
>
> On 1/11/2020 8:58 PM, Eric Greenwell wrote:
> > Charles Longley wrote on 1/11/2020 6:59 PM:
> >> Pfft compass what’s that? Look out the canopy.
> >>
> > Not a good option in Kansas! You are spoiled by flying where there are
> > mountains to guide you. In Kansas, look at the GPS track when you want
> > to know direction. Or pull out your iPhone, and use the compass app.
> >
>
> --
> Dan, 5J

Garmin's only precaution about the placement of multiple GPS antennas is the potential effect of one antenna shadowing another:

3c. To minimize the effects of shadowing at 5° elevation angles, the GPS antenna should be mounted no
closer than 6 inches (edge to edge) from other antennas, including passive antennas such as another
GPS antenna or XM antenna.

http://static.garmin.com/pumac/GA35GPS_WAAS-antenna_AntennaInstallationInstructions.pdf

And if you want to share a single antenna with multiple instruments you can get a splitter (albeit not cheaply!):

https://www.gpssource.com/collections/gps-splitter

Tom

[2G]

On Sunday, January 12, 2020 at 11:48:42 AM UTC-8, 2G wrote:
> On Sunday, January 12, 2020 at 8:27:19 AM UTC-8, Dan Marotta wrote:
> > ...or just look at the section lines on then ground.Â* If the sun is
> > shining, it's pretty easy to guess the cardinal directions.
> >
> > On 1/11/2020 8:58 PM, Eric Greenwell wrote:
> > > Charles Longley wrote on 1/11/2020 6:59 PM:
> > >> Pfft compass what’s that? Look out the canopy.
> > >>
> > > Not a good option in Kansas! You are spoiled by flying where there are
> > > mountains to guide you. In Kansas, look at the GPS track when you want
> > > to know direction. Or pull out your iPhone, and use the compass app.
> > >
> >
> > --
> > Dan, 5J
>
> Garmin's only precaution about the placement of multiple GPS antennas is the potential effect of one antenna shadowing another:
>
> 3c. To minimize the effects of shadowing at 5° elevation angles, the GPS antenna should be mounted no
> closer than 6 inches (edge to edge) from other antennas, including passive antennas such as another
> GPS antenna or XM antenna.
>
> http://static.garmin.com/pumac/GA35GPS_WAAS-antenna_AntennaInstallationInstructions.pdf
>
> And if you want to share a single antenna with multiple instruments you can get a splitter (albeit not cheaply!):
>
> https://www.gpssource.com/collections/gps-splitter
>
> Tom

Here is a cheaper splitter:

https://timemachinescorp.com/product/4-way-gps-splitter/?gclid=CjwKCAiApOvwBRBUEiwAcZGdGLHB6tEIS_Eyf8tbLep WCnRhzZvnGlbTKqADXrHfEJGPRK9H1kG_choC4g8QAvD_BwE

Tom

[Eric Greenwell[_4_]]

Dan Marotta wrote on 1/12/2020 8:27 AM:
> ....or just look at the section lines on then ground.Â* If the sun is shining, it's
> pretty easy to guess the cardinal directions.
>
> On 1/11/2020 8:58 PM, Eric Greenwell wrote:
>> Charles Longley wrote on 1/11/2020 6:59 PM:
>>> Pfft compass what’s that? Look out the canopy.
>>>
>> Not a good option in Kansas! You are spoiled by flying where there are mountains
>> to guide you. In Kansas, look at the GPS track when you want to know direction.
>> Or pull out your iPhone, and use the compass app.

If the sun is shining around noon or even somewhat later, it's mostly overhead.
It's really easy to pop out of a thermal and head off at 90 degrees to course.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

[Thomas Van de Velde]

The S100 accepts GPS data for FLARM positioning but not for navigation or logging. You have to connect a direct antenna. I have two pucks next to each other and have never had issues.

[Dan Marotta]

Ya got me there, Eric!Â* It's been decades since I've not seen mountains.

On 1/12/2020 9:26 PM, Eric Greenwell wrote:
> Dan Marotta wrote on 1/12/2020 8:27 AM:
>> ....or just look at the section lines on then ground.Â* If the sun is
>> shining, it's pretty easy to guess the cardinal directions.
>>
>> On 1/11/2020 8:58 PM, Eric Greenwell wrote:
>>> Charles Longley wrote on 1/11/2020 6:59 PM:
>>>> Pfft compass what’s that? Look out the canopy.
>>>>
>>> Not a good option in Kansas! You are spoiled by flying where there
>>> are mountains to guide you. In Kansas, look at the GPS track when
>>> you want to know direction. Or pull out your iPhone, and use the
>>> compass app.
>
> If the sun is shining around noon or even somewhat later, it's mostly
> overhead. It's really easy to pop out of a thermal and head off at 90
> degrees to course.
>

--
Dan, 5J