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VOR in roof?

A

aerhed

Well Known Member
Anybody see a reason I can't use copper strips laid in the underside of the roof of the 10 with a Balun for a VOR antenna? Same for GS (no balun)?
 
might work fine but why bother........or are you really needing that extra 0.1 of a knot? :D

DB:cool:
 
"might work fine but why bother........or are you really needing that extra 0.1 of a knot? "

DB

Uh huh, @ 200mph a 1/4" round rod VHF whip generates about five lbs. of drag. Ballparking 1.5 lb thrust per HP that sounds like waste to me. Plus, I've seen lotsa whiskers get broke. Skins cracked under blades & towel bars, and I almost got my eye put out by a (^&&^ VOR once. Also, I thought Archer antennas wound up in the wingtips because That's where the fiberglass was on most planes. As for line of sight, the classic location on a spammer is the vertical tip. What's gonna block reception in the fiberglass roof? The prop, or my little pinhead?
 
aerhed said:
What's gonna block reception in the fiberglass roof? The prop, or my little pinhead?
Click to expand...

All the aluminum below the FG top???

The VOR transmitters are on the ground as far as I know:rolleyes:

Try it. It will probably work, the big question is how well will it work???

Build it, fly with a buddy with whiskers, compare results, best way I can think of to answer this Q.

Good luck.
 
VOR antenna inside the roof - works great

aerhed said:
Anybody see a reason I can't use copper strips laid in the underside of the roof of the 10 with a Balun for a VOR antenna? Same for GS (no balun)?
Click to expand...

In Lancair land (320/360 flavor), Bob Archer antennas are routinely stuck on the inside of the roof in the baggage area. I use the one antenna with a splitter to drive two nav radios/CDIs one with glide slope. Work great and no drag.
 
Right, I've pondered about blockage on a localizer, like maybe forward fuselage or something, but maybe a forward vee would be best. I rolled all my own antennae on the inside of my Emeraude (VOR, MKR, GS, dipole Comm) and they've all worked stellar.
 
Mike, I think I will just try it. If I have to abandon it I guess I'm not losing much effort/cost and I can always try something else. I really don't like external antennas much as they look stupid and get beat up. My favorite are the old Beech boomerangs, looked like somethin' Huggy Bear would put on his ride.
 
I don't think "blanking" by the metal structure will be an issue. There have been too many airplanes with VOR antennas on the roof for this to be a problem.

800px-


Give it a try and let us know how it works.
 
For copper foil antennae. RST Engineering (www.rstengineering.com) has a kit that most of the canard folks use. Cheap it comes with a great booklet on copper foil dipoles.

That said, be sure to keep the tips away from any metal (door hinges) as this will cause signal issues.

Ryan
 
Hey, L@@K closely at the avatar......see any anteni...?

copper strips work fine for coms, nav.........

Not so sure about the metal, SWR might be very high..
 
That looks like a nice setup --- is it VOR and GS?

Looking forward to hearing how it works out...

-DC
 
Yes, that's VOR/LOC in the back & a GS in front. You can see the balun attached to the VOR. Nutserts are epoxied into the roof for terminals, the copper strips are punched for a screw and then heavily solder-tinned at the end to add some bearing surface for the screw.
 
I really like the clean look of this installation. Would you mind sharing the details of the balun and the dipole design? Are the antennas bent to alter their effective impedance?

Thanks,
-DC
 
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