Hi all!
Working on making a circularly polarized UHF yagi. They are mounted to
the same boom, orthogonal, but at a small distance, not a half wave.
Pic here:
https://www.flickr.com/photos/n3ykf/34924479053/in/dateposted/
Thought experiment: Lets assume I'd like to make these in phase at the
combiner. Since the farther (forward) yagi induces a signal into the
coax sooner than the second, nearer (to the back) one, if the coax
were the same length, then they would be out of phase.
Question: Does it matter if I make the coax connecting the farther
antenna shorter or the one connecting the nearer yagi longer (taking
into account velocity factor) to make it phase 0? I do understand that
this exercise is useless, except for comprehending the fundamentals
I do understand CP L/R is +/- 90
Plan is to use a combiner. One yagi direct to combiner, other through
a pair of spdt coaxial relays. Phase relationship: NC -90 / NO+90
The direct connection would be 1 wavelength, with the switched lengths
being 3/4 and 5/4, respectively.
Have a Sitemaster 113b to build the phasing harness. Lots of fun to
play with... The free tools from Anritsu allow measurements to be
taken on the instrument, ported to the pc and transformed into the
wanted format.
Norm n3ykf
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