Conor:
Assuming a steel whip in an air dielectric has a velocity factor around .97
then 108" is only a 1/4 wave around 26.5 Mhz,at 27 Mhz its closer to 106 ", at 27.18 5Mhz its around 105 inches at 27.500 MHZ its closer to 104 inches and at 28 Mhz its approx 102"
300/26.000/4 x.97 = 2.79m x 3.28 = 9.18 feet x 12 for inches = 110.13 inches at 26 Mhz.
300/26.500/4 x.97 = 2.74m x 3.28 = 9 feet x 12 = 108.05 inches at 26.5 Mhz.
300/27.000/4 x.97 = 2.69m x 3.28 = 8.83 feet x 12 = 106.05 inches at 27 Mhz
300/27.185/4 x.97 = 2.67m x 3.28 = 8.78 feet x 12 = 105.33 inches at 27.185 Mhz (US centre frequency)
300/27.500/4 x.97 = 2.64m x 3.28 = 8.68 feet x 12 = 104.12 inches at 27.500 Mhz
300/27.79125/4x.97 = 2.62m x 3.28 = 8.59 feet x 12 = 103.03 inches at 27,79125 Mhz, (UK centre frequency)).
300/28.000/4 x.97 = 2.59m x 3.28 = 8.52 feet x 12 = 102.26 inches at 28 Mhz
all figures rounded up or down as appropriate to 2 decimal points.
As you can clearly see, only one small section of 11m is actually 108" around 26.500 mhz. you will also notice for every 500 khz there is roughly a 2" jump.
Conor how can you say 108" whip is a 1/4 wave at 11m, thats only true for a small and nigh on unused part of the band around 26.500 Mhz. I'm sure you'll change the laws of physics again to prove me wrong.
for all you US guys buying 102" whips you'll also notice for your cb frequencies a 102" whip is too short, which is why you have to add springs to bring swr down unless you plan using it on 10m. get either 108 inch one and trim it, or even better a 108 " two piece one that can be adjusted at the centre for different lengths.
the mathematics is done for you, you gonny argue this one too?
Feel free to reeducate me,only tool i used was the calculator on my mobile phone, no online calculators or shite like that, feel free to double check my figures
NO BULLSHIT, NO SNAKE OIL, NO TRICKERY NO HYPE, JUST STRAIGHT FACTS AND FIGURES TO PROVE IT !!!
