[TenTec] G5RV

Steve Hunt steve at karinya.net
Sun Feb 1 09:57:12 EST 2009

Interestingly, it isn't always true that running the ladder line all the 
way is lower loss than using coax for part of the run.

Take the G5RV on 80m. At the end of the usual 30 odd feet of ladder line 
the impedance is about 14-j1. Any further length needed to get to the 
shack would be lower loss using RG213 with a 3.6:1 VSWR than 450 ohm 
line with a 32:1 VSWR.

Where circumstances allow, I see nothing wrong with choosing a 
combination of wire length and feeder length which results in "benign" 
impedances, either directly at the tuner or for minimising the loss in 
any further short length of coax. Actually, the G5RV isn't very good in 
this respect. The ZS6BKW is much better; with a 93ft "top" and 44 ft of 
450 ohm line it delivers a 50 ohm VSWR under 2:1 on 5 bands - 40m, 20m, 
17m, 12m, and 10m.

Steve G3TXQ

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