VOR antenna location

[Mudbud]

Where are folks mounting a VOR antenna?
The antenna I have in hand has a central part (hockey puck) that is 1 inch wider than the top of my vertical stabilizer.
Wayne New builder in Costal Georgia

 

[pierre smith]

Wingtip

Hi Wayne.
Spruce sells a wingtip antenna made by Bob Archer. It's very lightweight aluminum strips and lays in the wingtip. By the way, you can make a marker beacon antenna for the other wingtip by stripping the shielding off a 42" (as I recall) length of coax and simply placing six short pieces of 'glass and epoxy over it to hold it down and in place. We hid these for a cleaner airplane and less drag. The exception is comm.

Our comm is under the belly under the baggage area since the fuselage acts as a big counterpoise and our communications are excellent. Comm in the wingtips really can reduce your range/clarity, etc.

 

[KiloWhiskey1]

Wayne,

Here is a picture of the wingtip antenna that Pierre mentioned. I have spoken with Bob Archer, the designer, on several occassions and have every confidence that they work well. This antenna picks up frequencies for VOR, ILS, LOC and glideslope. A Coupler is needed to split the signal at the avionics end. The installation is easy. Here is a link to a website that has some good info. http://home.hiwaay.net/~sbuc/journal/sportcraft.htm

 

[painless]

I have one of the Archer nav antennas mounted in one of my wingtips and am extremely happy with it. I can pick up a VOR/AWOS signal that is 45nm away at2500' agl clear as a bell, and expect even further range with it.

Regards,

 

[Paul Eastham]

For those interested in the Archer antennas: you can buy them direct from him and save some $$$ over the spruce price. Check the link above for his email address.

Paul

 

[gmcjetpilot]

My suggestion

Where are folks mounting a VOR antenna?
The antenna I have in hand has a central part (hockey puck) that is 1 inch wider than the top of my vertical stabilizer.
Wayne New builder in Costal Georgia

My vote is for under the horz stab (click me an watch me grow).

Two nut plates and one hole for the coax. I just left the "Puck" exposed but it was not obvious being that you have to lay on you back to see it. You could make a cool fiberglass "canoe" fairing to go over the puck and pick up that extra 0.1 mph.

Drag: My calculations show about 1/2 MPH drag at 200 mph. When I raced I would remove the VOR antenna, secure the coax and connector with a little piece of safety wire and speed tape to cover the holes and secure the safety wire to fish the coax out for later antenna re-installation. Time to remove or reinstall minutes, at most.

The other location is on top of the Vert stab, but I would not do that for a tail dragger due to poke in the eye danger, ouch .

Here is a page from a builder site showing the vert stab installation.

http://www.n2prise.org/rv9a079.htm

IT does not look bad (see his main page pictures) and if you paint the black puck to match the plane color it will look fine. I prefer the white fiberglass VOR whips over SS, but it does not matter, just for looks.

Radio performance. I am going to say I expect (know) the above external locations will out better performance any internal wing tip NAV antenna. I have heard the internal wing tip NAV antenna works OK, as the above stated. However I have a pet peeve against the internal Comm antennas, they are lousy IMHO.

Good Luck, just my opinion. I don't think the external mount, especially on the belly way aft looks bad. In fact on my RV-4 it was almost invisible.

 

[dan]

Here is a picture of the wingtip antenna that Pierre mentioned. I have spoken with Bob Archer, the designer, on several occassions and have every confidence that they work well. This antenna picks up frequencies for VOR, ILS, LOC and glideslope. A Coupler is needed to split the signal at the avionics end.

Works great, I can attest to that. You couldn't pay me to put an eye-poker antenna outside the airplane when the one inside works just as well.

And as far as the "coupler" is concerned, if you use a radio like the SL30, which has an internal diplexer, then you don't need anything additional whatsoever. With other radios, YMMV.

 

[gmcjetpilot]

FLY OFF!

Works great, I can attest to that. You couldn't pay me to put an eye-poker antenna outside the airplane when the one inside works just as well.

And as far as the "coupler" is concerned, if you use a radio like the SL30, which has an internal diplexer, then you don't need anything additional whatsoever. With other radios, YMMV.

It would be fun to have a fly off and see what kind or range you have comparied? The "Works Great" is subject to interpretation is all I am saying. One time a guy with an internal Comm antenna told me "IT WORKED GREAT" and found out great to him was getting a scratchy ATIS by the time he was 5 miles out. There must be some directional aspect to the NAV antenna? May be not. Just would love some empirical experimental data.

I personally can't get too excited about it with GPS and the fact most use the "VOR" (slash LOC/GS) in the terminal area any way, so if it works on, SID, STAR, transition, initial, intermediate and final approach segments than I would say good enough.

 

[dan]

It would be fun to have a fly off and see what kind or range you have comparied? The "Works Great" is subject to interpretation is all I am saying. One time a guy with an internal Comm antenna told me "IT WORKED GREAT" and found out great to him was getting a scratchy ATIS by the time he was 5 miles out. There must be some directional aspect to the NAV antenna? May be not. Just would love some empirical experimental data.

Couldn't agree more...about the wing tip COMM antenna. That is definitely subjective, and I'm not 100% happy with mine. It works fine for my 2nd COMM but it's nowhere nearly as strong as the bent whip on the belly. Now this is COMM that I'm talking about.

As for the wing tip NAV antenna, "Works Great" means I've never had any issues receiving anything I was trying to receive. VORs or LOCs. I fly IFR here and there, but not a ton. I don't navigate by VORs, but I do use them for cross-reference when traveling. I have no hard data to back this up, but the range seems longer than what I've seen on any other external antenna setup on other airplanes I've flown. I'm not saying the wing tip antenna is BETTER, because it's probably NOT! I'm only saying "I haven't had any issues with range or reception whatsoever." So by that token, "Works fine" is how I'd describe it in my own aircraft.

COMM, think twice about using a wing tip comm antenna for your primary radio.

NAV, I wouldn't think twice about using a wing tip nav antenna. Or a marker beacon antenna for that matter (40" of virtually any conductor!).

 

[Sam Buchanan]

I'm only saying "I haven't had any issues with range or reception whatsoever." So by that token, "Works fine" is how I'd describe it in my own aircraft.

Same here. Even though I don't navigate with VOR on xcountries, a few times just for grins I've tuned in DCU when I was ~75 miles away (no more than 3500' AGL) just to see if there was reception. Even though the audio was weak, the NAV receiver flag was still off and a navigable signal was present.

I was out practicing some approaches this week (putting the new Trio EZ-3 pitch autopilot through its paces.....Man, it is cool flying these procedures without ever touching the stick!) and never did run into any directional issues. I have found the wingtip Archer Nav antenna to be reliable with both VORs and ILS localizers regardless of which way the plane is pointed.

Just another observation by someone who has actually used the antenna.....

 

[n2prise]

Go ahead with the vertical stab mount...

I put mine up there with the rods going forward for best exposure without either of the antenna elements shielded by the vertical stabilizer. You can see how I fabricated the mount on this page.

http://www.n2prise.org/rv9a079.htm

This page shows the first time it is fully installed on the airplane.

http://www.n2prise.org/rv9a118.htm#April29

Look at the fourth photo on this page for a close-up of the antenna installed on the VS.

http://www.n2prise.org/rv9a123.htm

Look at the SIXTH photo on this page in the paint shop.

http://www.n2prise.org/rv9a146.htm

And just in case you haven't seen the photos on my home page www.n2prise.org, look down below all the links and you will see the VOR antenna does not detract from the overall appearance. It works just fine for VOR and ILS.

Jerry K. Thorne
East Ridge, TN
RV-9A N2PZ Hobbs = 207.3 hours

 

[Bob Axsom]

I use VOR/GS/LOC

I use the VOR/GS/LOC for cross country navigation and approaches. They are all I have for legal IFR work and I do fly IFR. When I was building the airplane I called the developer (not Archer) of what looked like a potentially good set of in airframe antennas because I wanted to get minimum drag and maximum speed while maintaining an IFR capability. He was located in Florissant, Missouri (St. Louis). When I told him my intentions he was very honest, he said our antennas are intended mainly for the sport applications and the work well in that situation but I would not use them if you intend to fly IFR in real IMC conditions as part of your normal operations. Being an old USAF radio technician I didn't need any more explanation. My antennas are all "out there in the air" to give them the best possible performance opportunity. The "V" is mounted center forward with the "hockey puck" mostly covered by the vertical stabilizer cap.

Bob Axsom

 

[gmcjetpilot]

Well said

I use the VOR/GS/LOC for cross country navigation and approaches. They are all I have for legal IFR work and I do fly IFR. When I was building the airplane I called the developer (not Archer) of what looked like a potentially good set of in airframe antennas because I wanted to get minimum drag and maximum speed while maintaining an IFR capability. He was located in Florissant, Missouri (St. Louis). When I told him my intentions he was very honest, he said our antennas are intended mainly for the sport applications and the work well in that situation but I would not use them if you intend to fly IFR in real IMC conditions as part of your normal operations. Being an old USAF radio technician I didn't need any more explanation. My antennas are all "out there in the air" to give them the best possible performance opportunity. The "V" is mounted center forward with the "hockey puck" mostly covered by the vertical stabilizer cap.

Bob Axsom

Spoken like a true USAF radio man. Thanks for putting it into perspective.