If the elements are of different diameters, example 0.5 inches and 0.375
inches there are differences in Zo and slight differences in Fo.
To a first approximation I calculate 158.5 MHz as resonant point. That
may have a 2 to 3 percent error due to endeffects, L/D ratio etc.
Your calculation is a good as mine.
DD, W1MCE
Richard wrote:
"Richard" wrote in message
...
Hi. Can anyone please confirm for me the resonant frequency of the folded
dipole below?
(I calculate abt. 159.025 Mhz).
L1
------------------------------------
| | L2
--------------x L4 x---------------
L3 L5
Tube diameter = 10mm
L1: 90Cm; 35.43"; 2.953'
L2: 70mm; 2.76"; 0.230'
L4: 5.8Cm; 2.28"; 0.190'
L3&L5: 42.1Cm; 16.57"; 1.381'
As to calculators,I found two, but they are confusing to me.
Not very clear to me how to use this one:
http://n-lemma.com/calcs/dipole/fdipole.htm
Or this one:
http://www.optcom.net.au/wireless/folded_dipole.html