My first professor in antenna design said that a string of limp spaghetti inside
a copper septic tank made an antenna, and things could only get better from
there {;-)

Like everything else in aviation, the marker beacon antenna is a series of
compromises flying in loose formation. Can it be made shorter? Sure. Will it
work as well? Probably not. How much worse will it be? No way to tell without
building it and measuring it.

Given that at worst case you are only a few thousand feet above a 5 watt
transmitter with a thousand microvolt receiver, you can probably (I say again
PROBABLY) shorten it up if you wish. Even better, can you serpentine it around
so that it has the same length but not all in a straight line?

Jim


"Bart D. Hull"
shared these priceless pearls of wisdom:

-Does the marker beacon antenna HAVE to be the length stated in your manual
-or can it be scaled down?
-
-Reason I ask is I don't have the length available in my fuselage without
-going over large metallic objects. (Like a oxygen tank or rear tiedown mount.)
-
-Thanks for your support.

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com