Hi Dave, Basically your intent is to de-couple that antenna from the feed line for consistent performance, as such for a resonant dipole feed you can use a 1:1 balun, you internal antenna tuner will work much better.
A 4:1 balun for a resonant dipole will yield a higher VSWR at the point of resonance using 50 ohm coax. A 6:1 balun would be proper for going from 50 ohm unbalanced coax to 300 ohm twin lead to your dipole or from 50 ohm coax to a full wave loop antenna. If you wanted to make a multi-band doublet for 80m through 10m, then use a 9:1 balun with a short run of coax to the balun and 450 ohm ladder line to the dipole cut for the bottom of 80m. More than likely your antenna tuner will handle it well on 80, 40, 20, 15 and 10m due to the harmonic relationships with 80m, the same should be true of the WARC bands if its mounted in the clear, however use far outside the Amateur Bands for CAP, MARS etc. may challenge the ATU in your radio as it has a limited tuning range. /s/ Steve, N2CKH At 05:07 PM 10/18/2007, you wrote: >I understand the basics of using a balun, but have a question about the >specifics. Using a dipole, what would be the difference between using a >4:1 balun compared to a 6:1 balun? Which would I choose, and why would >I choose it? Planning on feeding the dipole direct from the tuner in my >IC-746 (non-Pro), if that makes a difference. > >Thanks! >Dave >KB3MOW
