That's the reason I use an external balun (external to the Tentec 238
tuner) to feed my balanced feed antenna system. The 4:1 balun is rated
at 5KW. The donuts (4) are about 4" OD and 2" ID. The windings are #10
with teflon insulation.
73
Bob K4TAX
Steve Ellington wrote:
>
> Yes indeed and that's exactly why the swr is so low on a G5RV when you
> use the suggested 70ft of RG8m. In addition to a Johnson Matchbox, I have
> an Ameritron ATR-15 tuner which has a large 1:1 current balun. The balun
> doesn't get hot on any band so I assume it's pretty efficient but
> Ameriton gives directions for rewiring it as a 4:1 voltage balun. I've
> tried this and the balun gets quite warm on some frequencies. Now consider
> the fact that most tuners, including the TenTec 238, have these 4:1
> voltage baluns. Try feeding an 80m dipole with 130ft of open line on 40m
> and the poor balun sees several thousand ohms. What's going to happen?
> Then try feeding this same antenna on 160m and it sees some real low
> impedance and divides this by 4! Where's the logic in this?
>
> Steve N4LQ
>
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