You mentioned in your post going on EZNEC. You definitely should model your
80m dipole for all of bands that you use it on. I think you'll find that on
10m it has a high impedance and a number of very deep nulls in the radiation
pattern.
John KK9A
Barry Jacobson WA2VIU
Hi, I need advice on getting one of the antenna analyzers on the market. I
have an 80 meter dipole fed with ladder line from an MFJ 989D tuner. I
seldom use 10 meters, but tried to go on the 10-10 phone contest today.
Would not tune in that segment of band. Tuner instructions say most
commonly need to shorten feedline by 1/8 wavelength at band that won't
tune. Before cutting line and possibly messing up other bands that work
fine, I would like to know exactly where I stand on each band. I could use
a device that will tell me exact length of line currently, and what effect
shortening will have on all other bands, and whether the new impedances
will be within range of capability of tuner. I don't mind learning complex
impedances and Smith charts if necessary, but want to do it systematically.
Don't know if devices out there do this for you. Some possibilities I have
heard of are NanoVNA, Rigexpert, MFJ antenna analyzer. I don't know if I
should go on EZNEC. The last 15 feet of each end of dipole droop
vertically, but don't think that's the main problem.
There is a whole page of devices. Don't know where to begin.
https://www.eham.net/reviews/view-category?id=31
Any advice from an expert greatly appreciated.
73,
Barry
--
Barry Jacobson
WA2VIU
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