Interesting Long wire antenna

[TA4AU]

Hi all.
Fisthyl my english not good i hope you understand me.

I have one antenna shematic and soon i will make this antenna. this antenna is long wire but have one non-inductive resistor in center.
of course firsth element is 1:9 unun and for 40 M. band full size wire and 500 ohm non-inductive resistor after 20M band quarter wave wire (5 meter wire)..... for 15 m. band quater wawe wire.... for 10 m. band. wire........... this antenna very old arrl hand book have. and my friend say me " this antenna has good gain for 20. 15. and 10 meter i will setup this ant. 25 meter up the ground i dont know any body have idea for this antenna or...

This antenna Work well ?
This antenna better than mono band Dipol ?
This antenna beter than fishin line antenna ?
This antenna will work 80 and 160 M. ?

best 73' TA4AU

[KA0HCP]

Hello Welcome!

I have never seen an antenna like that.  I don't see how it would work.  You would be better off to just hang a single run of wire of whatever length, a "random wire" instead.  Random wires have been used for decades and are about the simplest one can build.  I started out with one.  The other important part is to have a good ground.  There will be no gain.

In my opinion the best multipurpose antenna is a dipole of a resonant length for the lowest band you wish to work, fed with a balanced feeder like twin lead, window wire or open wire!  Of course you can also feed it with coaxial cable, the losses at high swr will just be a bit higher.

73, Bill

[Opcom]

I apologize but the drawing is too small for me to read it.

[TA4AU]

Click for full size image http://img376.imageshack.us/img376/5231/longwireix2.jpg

[K1JJ]

The antenna looks to be a simple "long wire" with a gimmick resistor and wire stubs to make it see about 50 ohms for each band after the 9:1 unun.   That power resistor will absorb and waste some power in the name of a better match, of course.

The same thing (and better) can be achieved using just a random wire and an ant tuner designed for long wire tuning. (Not a 50 ohm tuner in a rig)     A 120' wire would work fine.  

However, a simple dipole fed at the center will outperform this antenna. A "fan dipole" for multi-band use would be a good choice.   Also, an openwire fed dipole using a balanced tuner would be even better for multi-band.

T

[Fred k2dx]

I agree, for a multi band antenna: a dipole center fed with balanced open wire feeder & tuner is your best bet. The old handbooks show the 'magic lengths' of antenna and feeder that tune the easiest.

That design - with the resistor - looks like a way to waste power but see a low SWR. It might be better as a receive antenna. I wouldn't waste any effort trying it.   

[TA4AU]

Tnx for all reply. My friend say me for this antenna
7 Mhz. have 1 Wave size
14 Mhz. have 2 Wave size
21 Mhz. Have 3 wave size
28 mhz. have 4 wave size

And....
1 wave size have 1.2 Gain
2 wave size have 1.4 Gain
4 wave size have 2.1 Gain

its write old ARRL Book I want make this antenna soon but i must buy firsthly 500 ohm non-inductive resistor.

Best 73' TA4AU

[K1JJ]

Bear in mind that this LW antenna will have slight gain broadside to the wire on 40M. On 20M it will become a 4-lobe cloverleaf with a null broadside. On 15/10M the lobes will cluster more off the ends of the antenna.

So, if you position it broadside for USA on 40M, it will then perform poorly for USA on 20-10M, and vice-versa.


For dependable broadside work with reasonable gain and a fat lobe, the antenna should be no longer than 1 wavelength.  A good compromise is a centerfed openwire 120' long dipole for 40/75M AND an openwire fed   22' centerfed dipole for 10-20M.


T