Yes the MB antenna is quite long. I don't remember exactly,  let's see...a
marker is 75 mhz and the speed of light is 186,000 miles per second. Soooo
186,000 miles divided by 75,000,000 is 0.00248 miles, times 5280 is 13.0944
feet. That's should be the wavelength. The antenna is, I think, a half
wavelength or about 6 and a half feet or 78 inches. OK Scott, I'm counting
on you to check me on this.

Mine works well...very well. The problem is that you actually don't want it
to work that well. You should only receive a marker signal when you're
almost directly over the transmitter. With mine, I start hearing it a mile
before and continue hearing it a mile after passing the marker. Way too good
reception.

John,

 

Bill is correct. This time, he is correct about everything (a rare moment, I hear).  I have such a foil MB antenna on the fuselage centerline glued to the floor of the fiberglass body.  I pick up marker beacons all across the country - I use it as a nearest airport ILS alert.  It is too good.  Just report the FAF when the loudness reaches its painful peak, check the GPS moving map location or the highway in the sky indicator on your HUD.

 

BUT, if you plan to fly mainly in the US and in reasonable IFR conditions, please note that more and more marker beacons are being unplugged.  Why, just recently at my airport (KARR) on the ILS 9, the WOLFF (as in the life long airport maintenance family last name) OM was decommissioned and replaced with the radar-dependent DITCA (as in Mike Ditka, ex Bears/Saints coach) FAF.  Note also that most approaches with marker beacons no longer indicate a 50 foot penalty for them being OTS.  If you like RNAV/GPS approaches better (another way to get down on 9), DITCA is its FAF too. 

 

Anybody remember what an NDB is used for these days?  How about radio ranging?  Pilotage anyone, or are we just too fast for that?  Now where did I put my sextant?