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VOR/LOC/GS antenna

Rick_Aronow

I'm New Here
Looking for recommendations on brand & model and mounting of vor/loc/gs antenna for a -7A. Van's has a couple of different Commant & Rami that they sell. What are the pro/cons of the various models? My preference is to do a traditional mount in the VS, but I'm not sure how they would mount. I've got my VS complete, except for the tip.
Also, since VOR & LOC operate in the same frequency range wouldn't any VOR antenna also be a LOC antenna? Some antennas are listed as VOR/GS while others are VOR/LOC/GS.
 
Put an Archer Wintip Antenna in and be done with it! No draggy antennas to deal with!

cheers,
Stein.
 
VOR/LOC are same frequency. GS is a different frequency, but a harmonic of the VOR, so one antenna (with an appropriate splitter to feed the GS receiver) works just fine. Like Stein said, Archer in the wingtip and you're done.

IF you need a Marker Beacon antenna, about 40" of copper foil tape in the wingtip will suffice for that also. You will need another run of coax though. :(
 
Hi Rick,

If you go with the "cat whiskers" antenna you can easily mount it on the fuse below the HS. I didn't like the look of the antenna high on the VS, plus this location protects the antenna from people walking around the tail (and vice versa). You will need to reinforce the skin (as with almost any external antenna) with a doubler plate. We just installed nutplates on the doubler and then riveted the doubler to the skin. Very easy to install the antenna now since you only need to access the back side to connect the coax, and you can do that from the inspection holes. Like Dave said, just use a splitter (I might have an extra one at home I'll sell for a bargain) to use this antenna for your VOR/LOC/GS.

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From Rosie: Be careful the antenna does NOT flex enough to touch the fuselage. I had to shim mine with the UHMW strip leftover from the canopy.
 
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Mine's on top

Putting the rabbit ears on top of the vertical stabilizer enables you to fair in all but the outer rounded edges of the central hockey puck and retains the reception environment proven in certified IFR aircraft. When I was at the antenna selection stage I called the fellow in Florissant, Missouri that was marketing some good looking wing tip antennas. When I told him that I intended to use the airplane for IFR flying he said to me "My antennas are intended for sport flying and they work very well for that but if you are going to fly serious IFR I recommend that you install the best quality no compromise standard antennas and install them outside the aircraft with proper orientation, separation and location." I did and I have experienced no nav/com problems to date. You should consider you personal operational plans in making your final decisions. If you are planning strictly VFR that enables some drag reduction by enclosing the antennas. Personnally, I decided nav/com is one area I want no performance compromises in and I chose the conservative direction.

Bob Axsom
 
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Top mount

Bob, my first inclination is to take the conservative approach with a top mount, but I must say bottom mount looks interesting. Did you mount the antenna base on the top VS rib? It's too late for me to put in nut plates, how is your's attached? For those of you using the wing tip antenna's, how do you rate their performance? It sound like at least 2 people like them?
 
Rick,

I have Archer's Com2, Nav/LOC/GS and Marker Beacon antennae in my -6A wingtips. Nav in the left, Com & MB in the right.

They all work well. The Nav & Com do not have the range and clarity of a good external antenna but the LOC and MB have been adequate for the approaches that I've flown.

Ben
 
Here is my top mount

I made a little stand-off mount with platenuts for the antenna and pop rivited it the the top rib. Then the antenna is mounted on the base plate with screws (#8 or 10 I don't remember what I used). This works well for the old style Vertical stabilizer on the RV-6A. You will have to develop a mount for your particular application but then that's what homebuilding is all about.

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Bob Axsom
 
signal blocked?

SteinAir said:
Put an Archer Wintip Antenna in and be done with it! No draggy antennas to deal with.
Won't the airframe block signals from some directions?
 
Securing the coax at the top of the VS

Bob Axsom said:
I made a little stand-off mount with platenuts for the antenna and pop rivited it the the top rib.

Bob Axsom

Bob, How did you secure the cable at/near the top of the VS? Or is the BNC connection suitable?

Thanks!

Mike
 
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SteinAir said:
Put an Archer Wintip Antenna in and be done with it! No draggy antennas to deal with!

cheers,
Stein.

Just add a signal splitter in the feed wire and you have all 3 from 1 antennna.

Jekyll
 
Vote of the tail tip

How Bob did it, top of vert stab, is best for a "A" model RV's in my opinion. If you have a tail dragger put it on the aft bottom of the fuselage tail like n250jg did. (A VOR in the tip of the Vert Stab in a taildragger is an eye injury danger.)

I had my VOR on the bottom of the fuselage, tail area, and it worked well. The nice thing is with nut plates it's easy to remove. The belly installation is also begging for a little fiberglass canoe fairing over the mounting "hockey puck". Also if you mount the antenna a little further aft on the fuselage than shown, where the fuselage is narrower, the whips will not touch the fuselage skin. The Horz Stab may have some minimal effect on the antenna, but I never found it an issue and had excellent range on airways in mountains west coast. I also used the fiberglass whips verses the stainless steel.

Mickey's question about wingtip antennas and their performance is a good one. My experience and opinion is the VOR wing tip antennas kind-of-sort-of work almost OK. The NAV wingtips do work, but there is a compromise in range and omnidirectional characteristics. I guess if you primarily use a GPS and just want the VOR for the terminal area or approach it probably works OK. If you are trying to fly a long airway near the VOR's max service volumn, you might get an antenna induced MEA GAP or MRA GAP.

Personally I want max radio performance and happy to take the MAX 0.33 - 0.50 MPH VOR antenna drag at cruise speed. I don't get all the fuss over 1/3 mph to 1/2 mph. Now for COM antennas, they are truly marginal in my opinion. People say they work great, but great to them might mean talking to the tower 5 miles straight ahead, not to flight service station or ATC transmitter 100 NM away. Stay away from them for the COM. A COM antenna is only about 0.25 mph drag penalty and performance is so far superior to the wingtip ones it is a no brainer to me.

CLICK
 
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nose or tail dragging options....

hi,

my $.02 - the A models work well on the VS (well out of eye level), tail draggers probably good on the lower skin. I've ended up with one on the VS, COM2/NAV2 in the wing tip.

I made a support bracket for the puck and positioned it as far forward as I'd dare in the tip fairing.

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Other details / photos on the site under electrical-avionics

a template that might provide a starting point (make sure no scaling during the printing process)
http://www.rvproject.gen.nz/pdf/RV7A-Parts-VORAntenna.pdf

Regards,

Carl
 
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can you give me an advice about which vor loc gs antenna is good to install on the bottom fo the fuselage or on the top of the rudder , I preffer on the botton under the tail section ,
because on the wingtip I have 2 led lights and probable I will paint with metallic paint
 
Comant CI-125. Goes to a VOR/GS diplexer and thence to my radio. Works great, 21 years and plenty of ILS approaches and VOR navigation (not so much these days though).
 

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can you give me an advice about which vor loc gs antenna is good to install on the bottom fo the fuselage or on the top of the rudder , I preffer on the botton under the tail section ,
because on the wingtip I have 2 led lights and probable I will paint with metallic paint

Don’t do it. This is a quick way to get the nickname “one eye” when you do something around the tail, like tie it down. Add to that the point that there is no reason to do so.

Put it in the wingtip. It is easy to avoid RFI issues with LED landing lights and nav/strobes. Metallic paint being a problem has no basis. I have metallic paint on all three RVs and get VOR reception at 100+ miles, and ILS way beyond any practical range.

Carl
 
Comant CI-125. Goes to a VOR/GS splitter and thence to my radio. Works great, 21 years and plenty of ILS approaches and VOR navigation (not so much these days though), always worked great.

Diplexer, not splitter.
 
Archer wingtip VOR antenna

Put an Archer Wintip Antenna in and be done with it! No draggy antennas to deal with!

cheers,
Stein.

I second the Archer wingtip VOR antenna. I get over 100+ miles reception with mine @ 8500’ from both directions and mine is located in the right wingtip.

Brian
 
Put it in the wingtip. It is easy to avoid RFI issues with LED landing lights and nav/strobes. Metallic paint being a problem has no basis. I have metallic paint on all three RVs and get VOR reception at 100+ miles, and ILS way beyond any practical range.

Carl
+2 on the Archer nav, but install it correctly! I think I have seen photos of every way to install it incorrectly, including one where it was installed with the radiating element placed along side of, and attached to, the rib.
For the Archer com, the issue is getting vertical polarization. Tilt the leading edge of the antenna as much as possible up/down to max out the vertical component, but even then, it won’t match an external vertical antenna. Maybe 2/3 the range.
 
Comant CI-125. Goes to a VOR/GS diplexer and thence to my radio. Works great, 21 years and plenty of ILS approaches and VOR navigation (not so much these days though), always worked great.
I d like to install as in your photo
 
Yes, the first one. The others are for smaller, space limited wingtips. Only difference between left and right is the direction (up/down) of the connections (you can use a left on the right but the connections will face down. That may or may not be a problem depending on exactly how you attach the antenna. The given side (e.g., "left") assumes you are mounting the antenna on the bottom of the wingtip, and want the connections "up". If you for some reason want the antenna mounted to the top of the wingtip, with connections down, get a "right" for the left wing.)
 
Probably a dumb question - but does it matter if the whiskers point forward for backward? I have a comant CI-215 which I plan to install at the top of the vertical stabilizer, under the fairing, using nutplates to the top bulkhead deck.

I've walked around the airport and about 60% of the planes I see slope backward, 40% forward. One A&P said that forward might be a little better reception for ILS signals, but he didn't know any particular reason for one or the other. And I haven't seen anything about pointing forward or aft on any of the installation information.

Is there any reason for one or the other way, other than looks and preference?
 
Probably a dumb question - but does it matter if the whiskers point forward for backward? I have a comant CI-215 which I plan to install at the top of the vertical stabilizer, under the fairing, using nutplates to the top bulkhead deck.

I've walked around the airport and about 60% of the planes I see slope backward, 40% forward. One A&P said that forward might be a little better reception for ILS signals, but he didn't know any particular reason for one or the other. And I haven't seen anything about pointing forward or aft on any of the installation information.

Is there any reason for one or the other way, other than looks and preference?

To your specific question, no - it makes no difference. For that matter the elements can be in a straight line.

BUT DON”T DO IT! Use a wingtip antenna for VOR/LOC/GS. The eye ball you save from being poked out may be your own.

Carl
 
To your specific question, no - it makes no difference. For that matter the elements can be in a straight line.

BUT DON”T DO IT! Use a wingtip antenna for VOR/LOC/GS. The eye ball you save from being poked out may be your own.

Carl

I'm building an RV-10, not a -7. Just posted my question here since it seemed to be on topic.

If I was worried about poking out an eye from an RV-10 vertical stabilizer, I wouldn't need to build an RV-10. I'd be loving life in my Gulfstream with all my NBA salary money.
 
I'm building an RV-10, not a -7. Just posted my question here since it seemed to be on topic.

If I was worried about poking out an eye from an RV-10 vertical stabilizer, I wouldn't need to build an RV-10. I'd be loving life in my Gulfstream with all my NBA salary money.

I’ve seen RV-10s with the VOR antenna on the bottom of the fuselage, under the tail. Exactly where your eyeball will be when tying down the plane - or where a kid will be around your plane at some airshow. Same goes for these antennas mounted on the top of the VS for tail draggers.

My point - there in no practical reason to put the these ugly VOR antennas out in the breeze so why do it?

Carl
 
You raise a good point. The benefits of VS installation would be ease of servicing, single coax line, ease of installation. That would be it. I agree, buried inside would be easier, cleaner, and less likely to get broken off.

Although with Aveo winglets, I may have some interference and space considerations with all the other electronics that are already in my wingtip.
 
The benefits of VS installation would be ease of servicing, single coax line, ease of installation.

What servicing? It's an antenna...you mount it once (maybe twice if you haven't painted yet). And regardless of antenna, there's only one coax.

Wingtip antenna here, 10 years and working fine.
 
What servicing? It's an antenna...you mount it once (maybe twice if you haven't painted yet). And regardless of antenna, there's only one coax.

Wingtip antenna here, 10 years and working fine.

Aren't you supposed to change the ILS fluid once every 90 days? :)
 
RV9A, mine is in the wingtip, works great have flown ILS approaches down to minimums on perfect centerline and GS. However most of my real life approaches are GPS. (VOR, ILS, GS, LOC) very seldom used, today. I am so excited we don’t have ADF approaches anymore.
Mark

Looking for recommendations on brand & model and mounting of vor/loc/gs antenna for a -7A. Van's has a couple of different Commant & Rami that they sell. What are the pro/cons of the various models? My preference is to do a traditional mount in the VS, but I'm not sure how they would mount. I've got my VS complete, except for the tip.
Also, since VOR & LOC operate in the same frequency range wouldn't any VOR antenna also be a LOC antenna? Some antennas are listed as VOR/GS while others are VOR/LOC/GS.
 
Aren't you supposed to change the ILS fluid once every 90 days? :)

I put in a pump to refill the ILS fluid reservoir, with a switch on the panel. Really clean design.

As for servicing - the ability to fix it when my lousy coax crimping skills fail me?
 
RV9A, mine is in the wingtip, works great have flown ILS approaches down to minimums on perfect centerline and......
. I am so excited we don’t have ADF approaches anymore.
Mark

If you were really flying perfectly you’d notice that you were 13’ off the centerline - your wingtip would be on it! -:)

As a cfii I miss NDB approaches. Not that they were that great. But if an instrument student could fly one correctly in a crosswind, you knew that he had instrument flying figured out.
 
Friend of mine has a VOR/ILS antenna made out of a BNC bulkhead fitting and a piece of welding wire soldered onto it, installed in the wingtip. Total installed cost under $1.00. I did most of my IFR training in that airplane a few years back and it worked flawlessly.
 
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Those cat whiskers might as well be called "eyeball-poker-outers" I'm going with an archer antenna, and fully expect that the only time I'll ever use it is on an ILS.

Realistically, at this point I couldn't care less whether I can pick up a VOR 100 miles away or only 75...
 
Those cat whiskers might as well be called "eyeball-poker-outers"

WAY BACK in 1968, I took my T-Craft home for a re-cover. With the HS off, I was pushing the fuselage into the garage. I turned around to check clearances and promptly poked the VOR antenna into my eye. The ball went through my eyelid.

Fortunately it pushed my eyeball aside and didn't puncture it. I ended up with a little pain and some serious bruising, but nothing permanent. Pretty scary!
 
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