Don K5AQ to me mentioned the 50 ohm yagis in the ARRL antenna book. . I
have 20th ed so. let's see.
oh yeah Don's right..I guess I misremembered stuff..
But let's look at the performance:
using the ARRL/N6BV Yagi for Windows, the 2 element 19.5 ft boom
(240-20W.YW) has 2.0 SWR from just 7.025Mhz to 7.2Mhz. (at 60')
Maybe when I was playing with simulations, I was thinking "50 ohm swr <
2:1 for the full 7-7.3Mhz...with good gain and reasonable f/b --> not
possible). So while I said one thing in my prior post, I guess I was
thinking in the context of wanting <2:1 50 ohm swr over the full 7-7.3Mhz.
(which is one of the advantages of a moxon-like design)
Yes the 50 ohm goal is met in the ARRL design (20 ft boom, full length
elements) ... but not over the full band, right. Tweaking it to a lower
impedance, and matching it, can give better swr bandwidth?
I think my bent tip yagi shows that?. It's full length elements, bent,
with a hairpin (coil).
Maybe that was my point..tweaking a 40M 2L to 50 ohms, makes you give up
stuff....i.e. it's a peaky 50ohms.
-kevin
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