antenna and window question

[Tom G]

I'm going through about the longest annual I've ever had. My landing gear had to go out to the factory and the airplane has been disassembled now for several months.

I'm using the time to do some cosmetic repairs that wouldn't have gotten done normally.

I want to install a new antenna on the bottom of the airplane and was just wondering if anyone had any ideas on how to do this, parts needed etc. I would put it on top by my cover has a cutout for the ELT antenna and rather than deal with putting another hole in the cover I'd rather put it on the belly. Has anyone done this?

Also, I want to install new sliding side windows in the doors. The ones I have in there now are too thin. Does anyone know the proper thicknes for the windows?

Thanks!

[mhorowit]

Re: antenna and window question

Tom - how did you pack/ship the gear? - MIke

[8708]

Re: antenna and window question

Hi Tom,
Call Octavian at the factory. He has had good success putting an antenna on the bottom of the boot cowl.
Good luck!
Jay

[VictorBravo]

Re: antenna and window question

On my airplane there was a neat little ELT mount on the bottom behind the baggage sling. I commandeered the external ELT antenna for the COM radio, because the ELT unit itself had an antenna connector.

The ELT mount was done using a plywood floor piece, a truncated triangle about 18 or so inches on a side, which is shaped to match the section of tubing behind and under the baggage sling. This plywood piece has a matching aluminum sheet screwed into it on the bottom.

This assembly is clamped onto the tubes using rubber padded Adel clamps, so the aluminum doesn't corrode the steel. This aluminum is the "ground plane" for the antenna.

The antenna fitting is mounted in the center of the aluminum, and the antenna sticks out the fabric through a little grommet or reinforcement patch. Even a little blob of silicone sealer would suffice. The space on top of the plywood is used to mount the ELT unit itself.

So, I just plugged the COM antenna coax cable onto the BNC fitting for the external antenna, and plugged a new ELT whip antenna onto the ELT itself, and it has worked flawlessly. Well, I can vouch for the COM working flawlessly, and I'll hopefully never have to vouch for the ELT working...

[Tom G]

Re: antenna and window question

Mike: I took both landing gear to the UPS Store in my town and had them make a box and ship it. It was EXPENSIVE. I paid just under $200 to ship it down. From Northern New Jersey to Brownsville it took one week. The shipping on the way back was less, that came to about $125.

[Tom G]

Re: antenna and window question

I probably should have been more clear with regard to the antenna. What I want to do is leave the ELT antenna on top and put a com antenna on the bottom. Currently the com antenna feeds to the elt antenna with an AB switch. probably not the best arrangement!

[cpirrmann]

Re: antenna and window question

Therre's also an antenna strip that you can put inside the rear fuselage. I think Aircraft Spruce has some. I know I've seen it in Sport Aviation.

[Robert Lees]

Re: antenna and window question

Mike Jones has one of those strip antennas in his Taylorcraft in Illinois...ask him how it performs.

Rob

[Richard Boyer]

Re: antenna and window question

I would like to know the answer to this as well. I have been told that my antenna is too close to my headsets (I sound scratch when transmitting now).

[Joel Severinghaus]

Re: antenna and window question

I followed the example of several other Iowa Taylorcraft pilots and installed a 45 degree whip antenna ($23 from Wag-Aero) for my handheld so it pokes out between the shock cord covers, without needing to go through the fabric. Don't have a photo of the installation, but I'll take one next time I'm at the hangar.

[whake]

Re: antenna and window question

You will require a metal base as a reflector...check the WagAero catalog for antennas for fabric airplanes..I have mine mounted on top in the fairing between the wing and the fuselage and it transmitts fine.

[Mark Julicher]

Re: antenna and window question

Landing in tall grass may remove a comm antenna from the bottom of the plane, so place it as far forward as feasible.

Whip antennas require a ground plane. I know of three simple ways to have an effective ground plane. First, attaching the antenna to aircraft sheetmetal such as the boot cowl (or wing band on a top mount) is good, but the bootcowl is fairly weak and so a gusset or doubler is useful here. Second, firmly attach the antenna ground to the fuselage tubing. Weld a little tab on the tubing for this purpose or find a suitable place to put a screw into the tubing. I don't recommend drilling into a structural component and thereby introducing a place for rust to happen. Third, make a ground plane out of a cookie sheet. A good ground plane is 22 inches in diameter. It does NOT have to be perfect disk and it does not even have to be solid sheet metal.

A REALLY GOOD antenna mount: Make a sheet metal disk about 10 inches in diameter. Drill the center of the disk and mount your whip antenna. Add 8extension wires, each one 6 inches long, to the perimiter of the disk. At this point the antenna mount looks like a spider with a whip antenna poking out of its back. Mount this gizmo anywhere you want on the plane. Melt a tiny hole in the fabric for the antenna to go through. You could wedge the disk between the fabric and the fuselage stringers in the bottom of the plane...it will stay put.

[M Jones]

Re: antenna and window question

Mike Jones has one of those strip antennas in his Taylorcraft in Illinois...ask him how it performs.

Rob

http://www.advancedaircraft.com/ - is the link for the "strip" antenna.

I bought one years ago (when they were cheaper too) and mounted it on a 1/8" thick piece of plywood. The plywood is zip tied to the tubes behind the baggage sling. Because it's too long to be mounted completely vertical, as a comm antenna should be, it's at about a 45 degree angle. I have some issues with it, such as poor transmit towards the starboard side (it's mounted on the port side).

I have a whip antenna and an 18"x24" piece of aluminum for a ground plane that I had planned to try, but just haven't gotten it mounted yet.

I like Mark's idea for the disk with extension wires. Thanks Mark.

Mike

[marc]

Re: antenna and window question

Howdy all,I am working on a bc-12 the antenna I think I will use is a strip.my friend put one in a j-3 and says it the best.If any want to put rear window there a guy in shady cove that does this and lots of mod send a email and I will send the infothanks marc huntwork n43643

[Joel Severinghaus]

Re: antenna and window question

Here's a photo of the antenna installation for my hand-held radio. My avionics guy attached a doubler to the back edge of the bungee cords opening, then mounted the 45-degree whip antenna through that. There's a grounding wire attached to the airframe tubing. The antenna just pokes out between the bungee cord covers.