mounting of the AIRKIT antenna on trikes

[ozzietriker]

Hi all,

 

Does anyone have an AIRKIT antenna made by Mobile One (picture in attachment) fitted to their trike? if so, can you:

 

1. please let me know where you have mounted it; and

 

2. how it is affixed? - what type of mounting system did you make?

 

any pictures will be appreciated, please PM me for email address.

 

This antenna type cannot be mounted on the king post as it will cause the antenna to behave as an untuned di-pole and significantly reduce it's operating range.

 

The AIRKIT antenna is a completely ground independent antenna (doesn't need a ground plane i.e wing or flat suface to launch the RF waves) so i'm interested where you've mounted yours.

 

Thanks in advance :)

 

 

 

[horsefeathers]

Hi Oz.

 

My plane is obviously not a trike,but the Airkit antenna I fitted made an amazing improvement to my transmissions. I read of someone mounting it in their spat on a trike,and have attached a few pics for you. Note they used a plug at the spat to make it easier when de-rigging. (Pics come from http://forums.bmaa.org/default.aspx?f=15&m=50114&p=5).

 

Just for completeness, I show where I mounted mine. I bought my airkit pretuned to 127.0

 

Cheers

 

Gerry

 

 

 

 

 

 

[Zibi]

I'm not sure if it was exactly the same antenna, but I've seen them mounted in couple different places on the trike:

 

- on the keel with a purpose made strap, I think Airborne even had them in stock for a while

 

 

- on the side of the pod, but that was later moved to the keel mount

 

- on a bracket attached where the rear bottom suspension strut attaches to the trike.

 

 

[ozzietriker]

Hi Oz.My plane is obviously not a trike,but the Airkit antenna I fitted made an amazing improvement to my transmissions. I read of someone mounting it in their spat on a trike,and have attached a few pics for you. Note they used a plug at the spat to make it easier when de-rigging. (Pics come from http://forums.bmaa.org/default.aspx?f=15&m=50114&p=5).

Just for completeness, I show where I mounted mine. I bought my airkit pretuned to 127.0

 

Cheers

 

Gerry

 

[ATTACH=full]21150[/ATTACH]

 

[ATTACH=full]21151[/ATTACH]

 

[ATTACH=full]21152[/ATTACH]

 

[ATTACH=full]21153[/ATTACH]

Thanks Gerry for the info, that looks interesting!

 

cheers

 

Dennis :)

 

 

[ozzietriker]

I'm not sure if it was exactly the same antenna, but I've seen them mounted in couple different places on the trike:- on the keel with a purpose made strap, I think Airborne even had them in stock for a while

 

- on the side of the pod, but that was later moved to the keel mount

 

- on a bracket attached where the rear bottom suspension strut attaches to the trike.

Hi Zibi and thanks for your post, would you mind taking a close up pic of the bracket holding your antenna on the kingpost for me please. I'm curious how your bracket looks like and how it secured.

 

Thanks greatly :)

 

Dennis

 

 

[Guest roy.counsell]

You'll find that Yarrawonga Flight Training has a bracket that is easy to fit on the keel like the one on the XT

 

 

[Guest buzzard]

You'll find that Yarrawonga Flight Training has a bracket that is easy to fit on the keel like the one on the XT

Yes, I know of this and it works really well. Thanks Roy.

 

 

[Guest Andys@coffs]

I would not mount the antenna like the one in the spat. The radiation pattern on a 1/2wave dipole is like a donut put down over the top antenna element with the antenna in the donut hole...... most appropriate when the antenna is mounted as all the other photos but useless when mounted as per the spat. horizontally. Any aircraft in front and behind will be in a Tx/Rx dead spot. Generally the ones you have to worry about are those in front and behind you....

 

Details on raditation pattern here about 1/4 way down the page http://en.wikipedia.org/wiki/Dipole_antenna

 

However if you drilled a hole towards the rear of the spat and had the short rubber end inside the spat (not bent!) and the long flexible end straight up on top of the spat it will likely work.....but too much hard work for me when you can do the same thing off the front trike pod and that way the coax run needs to only be relatively short (Good thing!) and doesnt need any inline connectors (an even better thing!!) .

 

No matter where you put it remember that 1/4w antenna (The top long metal one) have an unerring ability to poke you in the eye on a regular basis! try really hard to put a rubber protective cap over the sharp end, preferably some bright fluoro colour as well......

 

If mounting on the pod remember that there are some drawbacks (cause lifes never so straight forward) the closer to the antenna you are the more raditation from it you will absorb. Power denisty reduces as a squared function as you move away so a doubling of the distance will be significantly less than 1/2 the power. Also humans arent the only thing to absorb RF energy, any wire will do that (good braid/foil shielding) will lessen the affect (actually thats not quite true, the braiding will still absorb, but the center cores wont and its the center wires signal that can be adversley affected) , and quite a few headsets/intercoms dont cope well with RF induction into their wiring, hence why a lot of trikers mount the antenna up on the keel post away from the intercom and other wiring/instrumentation.....

 

It worked without issue on my trike on the pod, but I have heard and seen others for whom it didnt work so well......On my trike Aerial pursuits provided the intercoms/headsets and the radio was a microair M760...

 

Andy

 

 

[cscotthendry]

Oz:

 

Here's a pic of an antenna mount I made for my trike. Essentiallt it's just a plug of nylon with a piece of angle bolted to it. The bolts are threadded into a solid rod running transversely through the nylon. I made the nylon fit into the keel tube with another hole vertically to take the pin that normally secures the keel extension tube. I found that I needed a the angle to tilt down at the back a little to make the bottom of the antenna tilt away from the prop when the wing was fully in the up position.

 

 

 

 

[Zibi]

Hi Zibi and thanks for your post, would you mind taking a close up pic of the bracket holding your antenna on the kingpost for me please. I'm curious how your bracket looks like and how it secured.Thanks greatly :)

 

Dennis

I'll see what I can do, when I'm at the field next time (it's not on my trike).

Here's the photo from Yarrawonga school shop, that roy has mentioned:

 

 

http://www.yarrawongaflighttraining.com.au/?page_id=104

 

 

[alf jessup]

Look very similar to mine Scott.

 

Alf

 

 

[ozzietriker]

I'll see what I can do, when I'm at the field next time (it's not on my trike).Here's the photo from Yarrawonga school shop, that roy has mentioned:

 

http://www.yarrawongaflighttraining.com.au/?page_id=104

Thankyou Zibi & MUCH APPRECIATED :)

 

Regards,

 

Dennis

 

 

[ozzietriker]

[ATTACH=full]21168[/ATTACH] [ATTACH=full]21167[/ATTACH] Oz:Here's a pic of an antenna mount I made for my trike. Essentiallt it's just a plug of nylon with a piece of angle bolted to it. The bolts are threadded into a solid rod running transversely through the nylon. I made the nylon fit into the keel tube with another hole vertically to take the pin that normally secures the keel extension tube. I found that I needed a the angle to tilt down at the back a little to make the bottom of the antenna tilt away from the prop when the wing was fully in the up position.

 

[ATTACH=full]21167[/ATTACH]

Thankyou Scott!

 

Great pictures, this looks like an excellent way of securing your antenna, a pro job too :)

 

Regards,

 

Dennis

 

 

[ozzietriker]

I would not mount the antenna like the one in the spat. The radiation pattern on a 1/2wave dipole is like a donut put down over the top antenna element with the antenna in the donut hole...... most appropriate when the antenna is mounted as all the other photos but useless when mounted as per the spat. horizontally. Any aircraft in front and behind will be in a Tx/Rx dead spot. Generally the ones you have to worry about are those in front and behind you....Details on raditation pattern here about 1/4 way down the page http://en.wikipedia.org/wiki/Dipole_antenna

 

However if you drilled a hole towards the rear of the spat and had the short rubber end inside the spat (not bent!) and the long flexible end straight up on top of the spat it will likely work.....but too much hard work for me when you can do the same thing off the front trike pod and that way the coax run needs to only be relatively short (Good thing!) and doesnt need any inline connectors (an even better thing!!) .

 

No matter where you put it remember that 1/4w antenna (The top long metal one) have an unerring ability to poke you in the eye on a regular basis! try really hard to put a rubber protective cap over the sharp end, preferably some bright fluoro colour as well......

 

If mounting on the pod remember that there are some drawbacks (cause lifes never so straight forward) the closer to the antenna you are the more raditation from it you will absorb. Power denisty reduces as a squared function as you move away so a doubling of the distance will be significantly less than 1/2 the power. Also humans arent the only thing to absorb RF energy, any wire will do that (good braid/foil shielding) will lessen the affect (actually thats not quite true, the braiding will still absorb, but the center cores wont and its the center wires signal that can be adversley affected) , and quite a few headsets/intercoms dont cope well with RF induction into their wiring, hence why a lot of trikers mount the antenna up on the keel post away from the intercom and other wiring/instrumentation.....

 

It worked without issue on my trike on the pod, but I have heard and seen others for whom it didnt work so well......On my trike Aerial pursuits provided the intercoms/headsets and the radio was a microair M760...

 

Andy

Hi Andy and thanks for your input!

 

Yes I sure can relate with what you've mentioned as some of those antenna placements were past experiences of mine. As you said antenna placement on a trike is definitely not easy like a conventional aircraft, I like the look of the rear keel mounts that Zibi and Scott posted and think that's where i'll mount mine. Mobile One recommended not to mount the AIRKIT antenna on the king post as it will cause the antenna to act like an untuned di-pole but at least 12 inches away from it.

 

Regards,

 

Dennis

 

 

[cscotthendry]

Mobile One recommended not to mount the AIRKIT antenna on the king post as it will cause the antenna to act like an untuned di-pole but at least 12 inches away from it.Regards,

 

Dennis

Dennis: That is exactly why I made the antenna mount for my trike. Also, after I made this, I had occasion to go to the Airborne factory and I talked to them about my mount. They said that a few people had made similar, and Airborne designed a mount using a piece of keel extension tube undercut on an angle so that the bottom of the antenna would clear. Theirs is a much simpler and lighter solution.

Alf: From memory, I'm pretty sure that I got the idea from you.

 

 

[alf jessup]

Dennis: That is exactly why I made the antenna mount for my trike. Also, after I made this, I had occasion to go to the Airborne factory and I talked to them about my mount. They said that a few people had made similar, and Airborne designed a mount using a piece of keel extension tube undercut on an angle so that the bottom of the antenna would clear. Theirs is a much simpler and lighter solution.Alf: From memory, I'm pretty sure that I got the idea from you.

Scott,

 

I'm pretty sure I sent you photo's of it, I should have taken a patent out on it as believe I was the first one to do it lol.

 

But now we have gone to the darkside it doesn't matter anymore.

 

Cheers

 

Alf

 

 

[cscotthendry]

Scott,I'm pretty sure I sent you photo's of it, I should have taken a patent out on it as believe I was the first one to do it lol.

 

But now we have gone to the darkside it doesn't matter anymore.

 

Cheers

 

Alf

Alf:

Yes I think that agrees with my memory of it. I'm also pleased to see that you've also come over to the dark side. I haven't regretted a moment of the transition to 3 axis.

 

 

[Mark11]

My antenna mount - very similar to a number of others in the hangar

 

The metal bracket and pipe clamp from bunnings

 

Aerial from mobileone - tuned to 124

 

3.6m from radio to hang point - connector - then 2m to antenna

 

Works beautifully