Cat whisker clearance

[clutch22]

I'm trying to get my CI-157P nav antenna installed on top of my VS. I wasn't expecting it to interfere with the rudder, but it does.
I assume it's okay to open up the angle of the cat whiskers??

[noelf]

Yes it is. The ideal dipole antenna is straight across. The cat whisker geometry is a compromise between ideal electromagnetic wave probigation, ethstetics, and aerodynamic form / function.

[BobTurner]

Well, a little bit is okay. If you go to a straight across dipole you'll get no reception at 3 and 9 o'clock.
How about just installing it 'backwards', e.g., pointy ends forward?

[9GT]

I installed mine so that the puck protruded about 1/2" forward of the leading edge of the V/S and faired it in with flox and micro. Looks very nice and I have about a minimum 1/4" clearance at the tightest point. I used a fiberglass Comant IIRC.

[rleffler]

Originally Posted by BobTurner

Well, a little bit is okay. If you go to a straight across dipole you'll get no reception at 3 and 9 o'clock.
How about just installing it 'backwards', e.g., pointy ends forward?

Actually, I believe that is the way Cobham recommends installing them (pointy end forward). Most of us, including me, install them backwards.

Please refer to the installation guidelines in case my memory isn't accurate.

[clutch22]

Thanks for the responses.
I guess I just like the way they look pointing aft better. I worked on it last night, and it looks like it's going to clear by opening them up about an inch wider at the tips. It didn't need a whole lot.

[Robert Anglin]

We did the same as above. After seeing a lot of Moonys down through the years and then talking to "RAMI" about it. We found that the VOR type antenna "Cat mouth hair type thingy" did not care which way you pointed it. Looks cool on there with the "V" facing forward. Sorry I don't do pictures on this sight to well. Yours as always, R.E.A. III #80888

[flion]

Following are a couple of pictures of my installation. Too late now for you but might be an alternative for those who haven't gotten to this stage. No clearance issues at all. The puck nestles perfectly in the top VS rib flange and I protected the holes for the antenna with rubber grommets, both to prevent chafing and to seal the exits.

[clutch22]

Originally Posted by flion

Following are a couple of pictures of my installation. Too late now for you but might be an alternative for those who haven't gotten to this stage. No clearance issues at all. The puck nestles perfectly in the top VS rib flange and I protected the holes for the antenna with rubber grommets, both to prevent chafing and to seal the exits.

Yeah, I like this method. If I ever build another, I'd plan for this type of install. I'm about finished with my setup. Just need to rivet everything together. I may post some pictures.

[clutch22]

Here are some pictures of how I made my mount. Maybe someone will find it helpful someday...