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Picture of Chris
Can a long wire antenna for HF be TOO long?
by Chris - Monday, 27 February 2012, 09:02 PM
 

Given I live ina bungalow I can have a long wire in a straight line from the apex of the roof (same height as the chimneys) to a tree about 30 yards away, or I could, weight of wire and wind factors aside, go berserk and go across the field to a big pine tree about 200 yards or so away. Is there any compelling reasons to choose the longer or shorter? I will be using this for transmitting and receiving. Can the wire be thin stainless steel? Anyone strung anything that long up who can say if it's viable, weight, stretch and wind factor wise, maybe ice formation wise, too, in a single run? Thanks.

 
Picture of Damian (G4LHT)
Re: Can a long wire antenna for HF be TOO long?
by Damian (G4LHT) - Monday, 27 February 2012, 11:35 PM
 

Here is a very good article on Long Wires.

http://www.w8ji.com/long_wire_antenna.htm

Regards

Damain

M0MVB
Re: Can a long wire antenna for HF be TOO long?
by steve - Tuesday, 28 February 2012, 11:28 AM
 

Hi Chris in reality a long wire can be whatever you want BUT all you need it to be is at least 1 wavelength at the lowest frequency you intend to use, A couple of yrs ago I did an experiment to see if a long wire could be to long, the answer was yes, I used 500 meters of electric fence wire the plastic and steal twisted type, it ran in a straight line suspended in trees and a couple of fishing poles, at a average height of 5mtr, it didn't need a tuner, but was very noisy, at my qth my noise floor is S0 on my hf log periodic switching to the long wire the noise floor was up to S5, as you have a bit of space have you thought about a fan dipole, I build one that was cut for 40 20 & 15 mtrs it worked well on most bands. Have fun experimenting
Steve M0MVB

M0MVB
Re: Can a long wire antenna for HF be TOO long?
by steve - Tuesday, 28 February 2012, 11:43 AM
 

Try looking here -->> http://www.m0mvb.co.uk/antennas.html 

It's my site, at the top of the page theres a pdf download of the USMC antenna handbook chapter 4-21 deals with long wires it also covers almost every antenna you can think of, please feel free to download a copy

Steve M0MVB

Picture of Chris
Re: Can a long wire antenna for HF be TOO long?
by Chris - Tuesday, 28 February 2012, 01:17 PM
 

Brilliant, will print this out when I find the new cartridge for my laser, which has gone walkabout. Thanks very much for the info and the link Steve, much appreciated.

Picture of peter m0pmj
Re: Can a long wire antenna for HF be TOO long?
by peter m0pmj - Sunday, 3 June 2012, 01:58 PM
 

hi chris,

not sure but i would consider making a wire with a few traps in or if you have more than 1 place to suport both ends several shorter wires resonant on your fav bands,

onl;y problem with long wires is unless they are resonant they pick up a lot of noise, more noise the further away from resonant frequency,

i know a few guys at my club whom swear by a web antenna with wires rewsonant to particular bands all running from 1 balun/ dipole centre, maybe thats worth looking into?

dont know if this helps you out but let me know some time,

73

pete

2E0CJK

 

Picture of Chris
Re: Can a long wire antenna for HF be TOO long?
by Chris - Monday, 4 June 2012, 11:06 AM
 

I have had a re think and have now put up a circa 150 metre long horizontal loop, fed at one corner where it is strung from the top of the gable end of our bungalow, by 450 Ohm ladder line to the ATU via a 4:1 current balun. The difference is staggering and I am now working most continents on 25 Watts. It's not perfect on all bands, but 15 metres is spot on and I regularly get good DX. The long wire seemed OK at the time, but either I hit lucky with the random length loop, or they are just a good antenna ;) I am thinking of extending it to another tree to make it more square, see photo. Thanks Pete. best reagrds Chris Wilson, was M6DFV,  now 2E0ILY.


Picture of Damian (G4LHT)
Re: Can a long wire antenna for HF be TOO long?
by Damian (G4LHT) - Monday, 4 June 2012, 12:25 PM
 

If it ain't broke don't fix it.

Damian 

Picture of Jamie
Re: Can a long wire antenna for HF be TOO long?
by Jamie - Monday, 4 June 2012, 12:26 PM
 

have you got an atu?

Picture of Chris
Re: Can a long wire antenna for HF be TOO long?
by Chris - Monday, 4 June 2012, 02:18 PM
 

Yes, the Yaesu FC-902 unit that was the period match for my old FT-902DM transceiver. On some bands it "likes" the 4:1 current balun between it and the feedline. I have bought an antenna analyzer, and when i get time (I am having to work twice as hard as five years ago just to stand stil.... :(  ) I will see what i can learn from it. Although a novice I have already realised antennas are like tyres on a race car. the best car (rig) in the world will seem junk on *rap tyres (antenna). We are lucky in that being in the sticks gives us the space to run some pretty long bits of wire, and we have plenty of trees to hang them from :) Cheers!