FLARM antenna question (hindrance from metal)

[2NO]

I am going to wave my white "not a hardware guy" flag again here (while ducking).

If the (main) FLARM antenna is mounted on a tin or aluminum surface (specifically, a short length of 0.5 by 0.1 inch of what is tin, aluminum, or some other light metal), will it interfere with the antenna's performance?

Or should I go with the wood alternative ... ?

~ted/2NO

[Richard[_9_]]

On Thursday, March 14, 2013 6:07:35 PM UTC-7, 2NO wrote:
> I am going to wave my white "not a hardware guy" flag again here (while ducking). If the (main) FLARM antenna is mounted on a tin or aluminum surface (specifically, a short length of 0.5 by 0.1 inch of what is tin, aluminum, or some other light metal), will it interfere with the antenna's performance? Or should I go with the wood alternative ... ? ~ted/2NO

See for some antenna solutions.

http://www.craggyaero.com/cables_&_antennas.htm

Richard
www.craggyaero.com

[Chris Nicholas[_2_]]

At 01:07 15 March 2013, 2NO wrote:
>I am going to wave my white "not a hardware guy" flag again
here (while
>ducking).
>
>If the (main) FLARM antenna is mounted on a tin or aluminum
surface
>(specifically, a short length of 0.5 by 0.1 inch of what is tin,
aluminum,
>or some other light metal), will it interfere with the antenna's
>performance?
>
>Or should I go with the wood alternative ... ?
>
>~ted/2NO
>


Dunno if this helps, but for my European (Swiss) Flarm, I had to
mount the Flarm GPS antenna a long way from my Logger antenna
(in fact on my headrest, whereas logger is on the instrument panel
coaming) to get an adequate GPS signal into Flarm. Dunno about
material for mounting – I use non metallic for that; and the other
Flarm-Flarm antenna screws into the Swiss Flarm plastic case so it
was not an issue.

HTH.

Chris

[2NO]

Thanks Richard ... did you get the email I sent you this morning asking about LX7007 firmware upgrade?

[bumper[_4_]]

2NO, if you are talking about the "rubber ducky" antennas that come on the portable PowerFlarm, they do not want to be mounted on metal (they don't need a ground plane).

For the center-fed dipole antennas that now come with the "core" (previously called brick). Again, no ground plane needed and they should be mounted as clear of metal (or conductive material like carbon fiber) as possible. Metal (or CF) is especially bad if nearby and in the same plane as the radials (not quite so bad if the metal is at right angles to the antenna radial, though it may still block RF if close. Also, be sure to keep the coaxial cable running straight away from the antenna for a few inches - - don't run it alongside the radial.

bumper

[2NO]

bumper,

I'm talking about the main bipole antenna (I have a core unit, not a portable).

Is that coaxial cable so poorly shielded that I have to create a special routing for it away from the radials? What kind of performance degradation are we talking about if the coax is, say, 1cm from the radial (and no metal is involved for the mounting)?

In PF's "Good Examples" section of their web page, the first example shows the coax lead running close to the lower radial. It also looks like a metal bracket, but I could be wrong about that.

2NO

[2NO]

That was here: http://powerflarm.us/powerflarm-installation-notes/

[Dave Nadler]

On Friday, March 15, 2013 9:36:32 AM UTC-4, 2NO wrote:
> I'm talking about the main bipole antenna (I have a core
> unit, not a portable).

DIPOLE !

> Is that coaxial cable so poorly shielded that I have
> to create a special routing for it away from the radials?

No, the outside of the coax is a ground, which needs to be
away from the radiating portions of the dipole.
Mount it on wood, plastic, or glass, AWAY from other
antennas and metal. PLEASE read and follow the FLARM
recommendations from PowerFLARM.us and ignore uninformed
speculation on RAS !

Hope that helps,
Best Regards, Dave

[bumper[_4_]]

On Friday, March 15, 2013 6:55:47 AM UTC-7, Dave Nadler wrote:
>
>
> No, the outside of the coax is a ground, which needs to be
>
> away from the radiating portions of the dipole.
>
> Mount it on wood, plastic, or glass, AWAY from other
>
> antennas and metal. PLEASE read and follow the FLARM
>
> recommendations from PowerFLARM.us and ignore uninformed
>
> speculation on RAS !
>
>
>
> Hope that helps,
>
> Best Regards, Dave

Dave,

Just to be clear, my reply to 2NO wasn't uninformed RAS speculation. I simply did not go into detail as to the reasons why, when I wrote, "Also, be sure to keep the coaxial cable running straight away from the antenna for a few inches - - don't run it alongside the radial.".

bumper

[JS]

Ted et al:
Saw an interesting FLARM antenna installation in Pete Alexander's ASG29 which according to Pete works fine. This seems a good option for any glider with carbon in the nose. The dipole antennas were protruding through the glare shield either side of center, with just one pole of the antenna in the pilot's view. I didn't pull the canopy off to see where the left hand one was relative to the vent pushrod. Suppose this could be done in tandem too, but the vent door may block reception directly forward.
Jim

[Dave Nadler]

On Friday, March 15, 2013 11:28:44 AM UTC-4, bumper wrote:
> Dave,
> Just to be clear, my reply to 2NO wasn't uninformed RAS speculation.
> I simply did not go into detail as to the reasons why, when I wrote,
> "Also, be sure to keep the coaxial cable running straight away from
> the antenna for a few inches - - don't run it alongside the radial.".
>
> bumper

No worries bumper, no one is going to accuse you of being uninformed !
See ya, Dave "YO electric"

[[email protected]]

Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum nose)

[[email protected]]

On Thursday, March 9, 2017 at 1:02:03 PM UTC-5, wrote:
> Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum nose)

An external mount might be a good option on a 1-26.

Does it have a nonmetal (fabric or fiberglass) nosecone?

On top of the instrument cover might be an option.

Chris

[SoaringXCellence]

> On top of the instrument cover might be an option.
>
> Chris

Chris, I'd guess you're not familiar with a 1-26:

The instrument cover is the metal nose cone. Top of the panel is the outside skin of the (metal)glider

[Martin Gregorie[_5_]]

On Thu, 09 Mar 2017 10:02:02 -0800, johnfwahl wrote:

> Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum
> nose)

On top of the fuselage behind the cockpit?


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Tim Newport-Peace[_4_]]

At 08:29 10 March 2017, Martin Gregorie wrote:
>On Thu, 09 Mar 2017 10:02:02 -0800, johnfwahl wrote:
>
>> Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum
>> nose)
>
>On top of the fuselage behind the cockpit?
>
Not a dipole, but 1/4-wave.

If a suitable place can be found, Below the fuselage might be better,
giving better reception from the direction where you cannot see.
>

[[email protected]]

On Thursday, March 9, 2017 at 1:02:03 PM UTC-5, wrote:
> Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum nose)

John,

When I had 192, I mounted them on a piece of plastic running between two arms of the A frame pretty high under the rear canopy. This seemed to work pretty well. I did have a clear rear canopy.

Kevin Anderson

[Martin Gregorie[_5_]]

On Fri, 10 Mar 2017 09:38:37 +0000, Tim Newport-Peace wrote:

> At 08:29 10 March 2017, Martin Gregorie wrote:
>>On Thu, 09 Mar 2017 10:02:02 -0800, johnfwahl wrote:
>>
>>> Any suggestion on mounting the Dipole antennas in a 1-26B (aluminum
>>> nose)
>>
>>On top of the fuselage behind the cockpit?
>>
> Not a dipole, but 1/4-wave.
>
Yep, apologies - I meant a bottom-fed rod antenna, using the 1-26 alloy
fuselage as a ground plane. Didn't think of 1/4 wave, being sometimes a
bear of very little brain.

> If a suitable place can be found, Below the fuselage might be better,
> giving better reception from the direction where you cannot see.
>
Judging from photos, there isn't much clearance between a 1-26 and the
ground, so antennae mounted on the underside may get a lot of damage.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Brian[_1_]]

A Metal nose (not the nose cap) 1-26B would be a bit rare, most have a fiberglass nose I believe the 1-26A had a fabric nose. in which case mounting high in the nose would probably work good to fair. Of course a 1-26D or E has the metal nose so mounting an external 1/4 wave antenna is probably a good solution.

On all except the E model, one could consider mounting a dipole antenna as far back and low as possible in the Fuselage, As far back to minimize the cockpit metal from blocking the forward signal an as low as possible to get it as far away from the upper aluminum deck on the fuselage.

Brian
CFIIG/ASEL

[[email protected]]

I own a B4 with a plastic nose cone. I have a dipole strapped to the front most frame.
This gives me a very good range forward and still a decent range in other directions.

I used to have a mono pole mounted on the back of the glider, just behind the wings. This gave me horrible coverage in most directions. Especially downwards, due to the wings.