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Old 02-14-2020, 10:57 AM
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BlackhawkSP BlackhawkSP is offline
Join Date: Jun 2011
Location: Indianapolis
Posts: 210

Originally Posted by Pilot135pd View Post
I've been researching this for a while now and I'm going to do it for my VOR and GS this weekend but my plan was to install it in front of the canopy arc like in this thread

For the last 3 weeks researching this my doubt has been, and I'm still trying to it figure out, why everyone is using 16" because 234/113 Mhz (middle of frequency range) = 2.07 feet not 16" !

What length did you strip on your RV-8 and why?
First of all, the GS frequencies are 329 to 335 MHZ. If you used the listed 234/113, that's why your math is not working out.

Using the formula of WAVELENGTH X FREQUENCY = SPEED OF LIGHT (C) and run the numbers for the middle of the band for GS frequencies, the math works out as 35.55 inches for a full wave antenna. This makes the exact length of the stripped portion of a 1/2 wave antenna at 17.78 inches. The 16 to 17 inches of the stripped center conductor of a piece of coax stuffed down the gear leg of my 8 has worked perfectly for years.

Would do it again in a second:-).

I had to get the calculator out and shake off a few cobwebs in the brain on that one:-)....

Larry Anderson
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