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End-fed 160m wire

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May 5, 2005
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533
Location
West Central Arkansas
#1
I am trying to build an end-fed 160m antenna. My tower is 38' tall and I've strung a wire in an "L" shape from the base to the far corner of my half acre. I bought a combo 4:1 and 9:1 balun (unun?) made for long wires but I can't seem to find the correct length for the long wire.

Can anyone help me finish this project?

I do not want suggestions for different antennas, they won't fift the lot. My tower is only 15 feet from the end of the lot so a dipole is out of the queston. The long wire "L" is the only thing that will fit.
 
Joined
Jun 30, 2006
Messages
7,529
Location
So Cal - Richardson, TX - Tewksbury, MA
#3
As mentioned there are a number of "magic" lengths that will match a 9:1 on many ham bands including 160m. I believe 73ft is one and 117ft is another depending on who's chart you look at.

However, with most of the lengths shorter than about 200ft, a 9:1 balun will be more of an attenuator and the antenna efficiency will be grim at best. On a 9:1 end fed, the coax is an integral part of the antenna and radiates about as much as the wire. More coax is good in this case because its more antenna to radiate.

If you want an end fed for 160m that actually works well you would go with a full 1/2 wavelength of wire (about 250ft) fed with a transformer that has a very high impedance output to match the 1/2 wave end fed.

Several companies make the transformer and complete antennas and if you have the space you will be rewarded with a good performing antenna.
prcguy


I am trying to build an end-fed 160m antenna. My tower is 38' tall and I've strung a wire in an "L" shape from the base to the far corner of my half acre. I bought a combo 4:1 and 9:1 balun (unun?) made for long wires but I can't seem to find the correct length for the long wire.

Can anyone help me finish this project?

I do not want suggestions for different antennas, they won't fift the lot. My tower is only 15 feet from the end of the lot so a dipole is out of the queston. The long wire "L" is the only thing that will fit.
 

SCPD

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Joined
Feb 24, 2001
Messages
65,126
Location
Virginia
#4
This may change the subject a bit, but it seems you are proposing a horizonally polarized antenna. At 160, unless it strung very high- the likes of which most hams can't even dream of attaining, the performance will be very poor. Have you consider'd using your tower to support some sort of top-hat vertical?- a wire off the side, a collection of insulators? a good counterposed ground system?...Base loaded, an antenna that length will give a nice ground wave signal, and since most 160 mtr. propagation of any measure is vertically polarized, it should work out surprisingly well (like any AM broadcast station) and should fit nicely within the foot print of your available property limits.
.
Just an idea
..............................CF
 
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Joined
Aug 16, 2015
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338
Location
Santa Monica, Ca.
#5
end fed 160

Balun designs also makes a 1500 watt 55 to 1 balun for half wave ant. I have a qso king 9 to 1 with 53 feet of wire that gets 1.2 to 1 swr with tuner.on 160.
 
Joined
Jun 30, 2006
Messages
7,529
Location
So Cal - Richardson, TX - Tewksbury, MA
#7
Very good point, I've played with a few low dipoles in the 20 to 30ft height range on 160m and never got any good performance. Its about the equivalent of an 80m dipole 10 or 15ft off the ground or a 40m dipole at 5 to 7ft off the ground.

On the other hand, some recent experiments with a 32ft and 43ft vertical with auto tuner at the base and some ground radials gave me surprisingly good signals on 160m and especially the 43ft. The 43ft originally came with a 4:1 balun for all band use and it was more of an all band dummy load. Replacing the balun with an auto tuner at the base really perked things up and stations 200mi away on 160m that would not respond to me with the balun gave me good reports with the autotuner.

If you can borrow or cobble something together to test a low end fed without spending much it might be a good test to show what level of performance you get at that height. If it doesn't work out as expected you then you can move on to something else without having a lot invested.
prcguy



This may change the subject a bit, but it seems you are proposing a horizonally polarized antenna. At 160, unless it strung very high- the likes of which most hams can't even dream of attaining, the performance will be very poor. Have you consider'd using your tower to support some sort of top-hat vertical?- a wire off the side, a collection of insulators? a good counterposed ground system?...Base loaded, an antenna that length will give a nice ground wave signal, and since most 160 mtr. propagation of any measure is vertically polarized, it should work out surprisingly well (like any AM broadcast station) and should fit nicely within the foot print of your available property limits.
.
Just an idea
..............................CF
 
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