[Elecraft] EARC End Fed 6-40 question (Was Re: cobweb antenna)

[Dennis Moore]

I also wound one of these ununs according to their directions. The 
drawback to this antenna is that it uses the shield of the feedline as 
the counterpoise. If you try ferrite beads, or even winding an air 
choke, I would think they'd need to be closer to the rig than to the unun.

73, Dennis NJ6G

On 5/31/2013 12:35 PM, Jeff Ellis wrote:
> I got the kit John talks about and made the antenna. Its was quick and fun to make.  I have a question about it though. I had a 70' wire that I had been using just for RX to test a IC-718 and I hooked it up to the UNUN box instead of the 30' wire that came with the kit. Its below 2:1 on 6m, 12m, 17m, 40m and less then 4:1 on 10, 20m, 80m and about 6:1 on 30m, 160m. The only really high one is 60m.  So really all but 60m are tunable by the KX3 tuner board. I am using what I remember to be about 15' of RG-58/U. My Shack area is on the second floor of the house and the wire goes out my window and down to the back fence.
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> My problem is I am getting RF coming back into the shack (on just 5W) where it will reset my USB hub a few feet away from the radio. Not fun when trying to work digital modes. This only happens on some bands but I know happens on 20m where I try and work the most. I expect its just the ones less resonate that its doing it on but I need to check again.
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> Will adding a number of ferrite on the feed line help choke the RF? Will winding the feed line around a tube to make an air choke work? I guess that one is cheep enough I should just try it. Buying 10 or more ferrite to clamp to the line costs more ;)
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> What about using a longer feed line? I really don't want to add a counterpoise and the instructions said it does not need one. I could use the 30' antenna wire it came with if that is going to help. I would not think so since its resonate on so many bands and tunable on the others.
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