Hi All,
The house I just bought precludes me from even using my arrow inside as there must be something un-RF friendly in the walls. Therefore, I was looking for a roof antenna and the October QST article on the QFH inspired me to build one. However, after doing some research, I have come up with two sets of design specs and I'm unsure which one is correct.
I converted everything from you're the 146Mhz QST model to 436Mhz. However, when I plug that info into http://www.jcoppens.com/ant/qfh/calc.en.php
The values it puts out are different in the "compensated length" field. The only difference is this model calculates for a full turn as opposed to a half turn, but the lengths shouldn't be as different as it says. Under the QST model, I get a wavelength of 688mm, but under the website's model, it gives me a "compensated wavelength" of 729mm.
The values I used to calculate are:
436
1
1
15
2
.23
Can anyone tell me which specs to use and/or explain this compensated wavelength issue?
Thank you,
Tim
KI6VBY