Cat's Whisker Omni antenna placement

[Sam Staton]

I read the note on the front page yesterday about placing a cat's whisker antenna for better omni reception. My question about this (since I have not started the vertical stab yet) is what issues would arise by placing the antenna in the 'traditional' place - the top of the vertical stab? The structure seems to be very simple in the vert stab. I guess my real question is this - what support structure would I need to place if I wanted to locate it there? Thanks in advance for all input!

 

[Alan Carroll]

No issues if you point the elements forward, unless you just don't like the way it looks. I have it mounted this way and it works great. I remove the antenna for racing, but honestly I can't tell any difference in speed.

With a taildragger the elements will be at eye-poking level if facing backward - not a good idea.

There are a number of previous threads that talk about alternative locations.

 

[Sam Staton]

Omni Antenna placement

Hmmm ... hadn't even thought of the whiskers facing backwards. Forwards seems the right way to do it. Was looking for what folks have done in the way of physical mounting - backing plates, etc. Have also thought about placing the antenna in the fiber glass fairing at the root of the vertical stab. Good to know that it has been done at least once!

 

[mikehoover]

Here are a couple of journal entries of how my antenna is mounted:
http://www.aclog.com/rv-9a/index.php?c=1#920
http://www.aclog.com/rv-9a/index.php?c=1#918
Keep in mind that I have not flown yet, but my tech advisor has looked at it and says it looks like a good solution. It will require a little creative cable routing up through a hole/grommet in the VS top rib forward of the mount, anchored with an adele clamp w/screw/nut in VS top rib flange and a VS skin to VS tip rivet hole. The cable will loop over the top of the mount/antenna and down through a hole/grommet in the VS top rib aft of the mount, and finally loop up to and connect to the antenna. This will allow me to have a service loop and also allow me to secure the cable at the top and bottom ribs of the VS. I was initially tempted to just secure the cable as it enters the bottom VS rib with an adele clamp and go up straight to the antenna, but it was suggested that that might not be a good idea, thus the loop rig described above. More or bigger lightening holes in the mount would be better to reduce weight. Comments/suggestions are certainly welcome.

 

[Sam Staton]

Omni Antenna placement

Mike -
Looks very professionally done. I am curious though, as to why the very thick mount. Would also be very interested to see how you routed the cables. Thanks for the pics!