Van's foil nav antenna

[frankh]

Any of you good people using the 25" of CU foil in the wingtip as the NAV antenna?

Any problems with getting it to work?

Reason I ask is...2 days after my GNS 430 shows up I had to send it back because garmin found some bad components.

Anyway, Archer wingtip comm antenna worked great in the hangar but I could not pick up anything from the VOR transmitter on the field even if I pulled the airplane out the hangar.

The weather sucks so flight test was not viable prior to pulling the 430 out.

So..Should I expect to hear the ident even with a horizontal foil antenna with the VOR about a mile away behind a few steel hangars etc?

I'm trying not to put off the CFI for another week if the antenna is a dud.

Thanks

Frank

[gmcjetpilot]

ANY internal antenna is a compromise.

Internal wing tip NAV antennas seem to work fair, since they just have to receive. The performance of the ground station is the key. In the terminal area, it works adequately as reported by several users, but with some directional aspect when the wing tip antenna is blocked by the airframe. Enroute, at max distance or edge of VOR service volumn you may have some issues. For LOC and G/S it should be OK.

Internal VHF com antennas are poor any way you cut it. That is the common consensus. When people report it works, that may be talking to tower less than10 away.

The foil antenna in the wind screen seems to work OK for Com in terminal areas, with station in front of air craft. Over all performance is poor.

My advice to anyone is seriously consider using external antennas.

A Com antenna at top speed is about 0.25-0.30 mph drag.

A Nav whiskers at top speed are good for about 0.50 mph drag

Transponder at top speed, nominal 0.125 mph drag

** All three less than or about 1 mph. For 1 mph you get max performance from your radios. To me the Com is a safety item. Good clear communication should not be compromised. The Nav is less critical with GPS now a days. However for approach, LOC and G/S should be strong with no compromise.

Speaking of GPS antennas, they're small and look up, horizon and above, so the antenna can usually be placed under the canopy or cowl.

I put the Com antenna and Transponder on the belly fwd of the main spar. This give short coax runs. I like the Nav whiskers belly mounted under the horizontal stabilizer. The coax run is longer but not longer than runs out to the wing tip.

Good Luck


** When I "raced" my RV-4 I took the Vor and Com antennas off and used a hand held or internal Com antenna. Nav was from GPS. I could remove both antennas in about 5 minutes.

[lucky333]

I'm with George.
Am ordering my external COM and XPDR antennae now. What did you use for NAV, George?
Thanks,
John

[Ironflight]

I ordered the Van's foil Nav and Comm antennas back when I was buying parts, but after looking at them, and not being particularly impressed with how the cable would be attached, I installed archer antennas in each wing tip - one for Comm 2, and the other for VHF Nav. George is absolutely correct if you want/need maximum performance - you should go external. Since I have 3 GPS's, my VHF nav is primarily for ILS/Loc use, and the #2 Comm is for short range use, so I'm happy with what I have.

But the foils are still in a box somewhere!

Paul

[lucky333]

Paul, does that mean that you are using externals for COM1 and XPDR?
Thanx
John

[jbDC9]

Originally Posted by Ironflight

I ordered the Van's foil Nav and Comm antennas back when I was buying parts, but after looking at them, and not being particularly impressed with how the cable would be attached,

Yup, I bought the foil nav antenna and was a bit underwhelmed with the attachment method as well; soldering the center wire of the coax to the foil. I went ahead and gave it a shot, soldered it, two layers of heatshrink, then a layer or two of glass to hold it in place. Haven't flown it yet, just taxied around Hooks airport; shows good reception of the localizer signal but can't hear the ID code.

So, I'll try it and fly it. We'll see how it works, but there might an Archer antenna in my future...

John Bixby
RV-8
Houston

[Ironflight]

Originally Posted by lucky333

Paul, does that mean that you are using externals for COM1 and XPDR?
Thanx
John

Yes, Comm 1 and the Txpndr are on the belly.

[frankh]

I used a ring terminal and a C/S #6 screw thru the bottom of my painted wingtip...How could I?...Because I havent used a VOR in 8 years I kinda "forgot" to see if the needle was centering up with the radial change.

Actually my CFI suggested I should have done that...right after I sent my GNS 430 back to Garmin to replace the flaky components...Nice..

Frank

[lucky333]

Originally Posted by Ironflight

Yes, Comm 1 and the Txpndr are on the belly.

Thanx Paul.
RJO

[gmcjetpilot]

Originally Posted by lucky333

I'm with George.
Am ordering my external COM and XPDR antennae now. What did you use for NAV, George?
Thanks,
John

Nothing on my -7, going GPS, potable & little antenna under glass (canopy). My RV-4's antenna, fiberglass whiskers, two hole mount. Forgot, but think it was a COMANT CI 159C. The white blended nicely with the white plane, but stainless steel works fine. The mount was just a black "hockey puck". It just went flat under the tail. Three holes, two mounting screws w/ nut plates and one in the middle for the coax connector. I could have made a little fiberglass canoe fairing but I just left it, less is more. Any brand will work, stainless or fiberglass. Some have 2 or 4 screw mounts. Two mount holes is easier than 4 and that was what I had. The fiberglass is suppose to perform better?

As I said when I raced so to speak, I took the VOR antenna off to "go fast" (wow a whole 1/2 mph). Two screws, 1 minutes; Pull the coax out - disconnect from antenna - attach a little safety wire to it, 1 minute; Stuff coax/connector back in - tape over the hole and exposed safety wire, 1 minute. To put it on was just reverse and required just screw driver.

I had it connected to a King KX-155 with VOR/LOC/GS and it worked. What can I say it was a VOR. Even the best VOR installation has limitations. I did fly IFR with it as my sole NAV source. It just worked as you expected. Enroute the performance seemed acceptable and gnd VOT/VOR test always where received. On tail draggers I don't like the VOR on top of the Vert Stab because of eye hazard. Model-A, the top of the Vert would work as well or even better? The disadvantage is more coax run and harder to remove.

A 1/2 mile per hour drag penalty is worth it for good VOR NAV performance, especially if IMC/IFR and it's your sole nav. IMC near the COP (change over point) an an airway w/ needles dancing, ambiguity pointer flopping, is not fun. I flew IFR in some rough freight planes before GPS or LORAN. Weak VOR receivers for what ever the reason "concerned" me. I didn't like the feeling or ever want to repeat it. Thanks to GPS its not such a pucker factor if the VOR needles flop around.

If I where to equip my RV IFR again, I'd go IFR-Lite and still rely (officially) on ground base Nav. IFR approved GPS's and their nav data base revisions are expensive. An "all-in-one" VOR/LOC/GPS receiver and a few paper enroute charts and approach plates, updated as needed, can get you into the system. Of course IFR GPS's are awesome, but for IFR Lite, IMC departures to VFR, enroute let downs through an undercast to VFR and high Min approaches, a VOR still is a handy and a cheap way to get some IFR capability. I flew a Piper IFR with a single VOR/LOC and MB. It worked for the places I needed to go. However if that one nav/com puked, it wouldn't have been pretty, so I picked my days to fly IMC. I suppose my hand held com/nav could have saved the day? Never had to try it but my test in the plane showed it was marginal. May be I could get a GCA or PAR approach using the portable handheld. The handhelds VOR radial read out was unusable with the rubber ducky antenna, drifting all over the place. The brand of radio, STS is defunct, but I still have it. The Com works fine, but if you plan to use any handheld radio for real backup COM, have a way to connect it to the external antenna and a headset.


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