Hail the Dipole

[WU2D]

I have run a long Inverted L forever. It is 25 feet of RG-8 into a large L tuner in my bulkhead and goes straight up 50 feet and out horizontal to the woods. As long as 250 feet and as short as 160 Feet. It lets me put a signal out on all bands including 160. With 100 - 200 Watts, it gets out but I have no great signal.

And I have run Ground plane antennas with elevated radials with good DX results on 75M.

For the upcoming 1929 AWA contest I decided to try something different. For some reason I thought about putting up a simple dipole on my woods feedline. I simply cut 130 ft of # 12 and made an inverted Vee insulator and end insulators out of a piece of PVC pipe. I also built a Guanella 1:1 Balun with 15 turns if enamelled #12 on an old AM Radio Ferrite Rod (No heating and tested at 200 Watts and it beat my 2KW Torriod for loss and match).

I managed to pull up to about 40 feet with old RG-8 I had so I figure I had a run of about 130 feet of coax from the shack with one switch inline out in the woods.

The ends of the inverted Vee are about 15 feet of ground.  So I had a low inverted Vee in the woods all below the canopy.

I did an A-B during the OMRN CW net last night and the simple dipole is kicking the inverted L around the block. It hears and transmits better. Gee these dipole things work.

Mike WU2D

[N3DRB The Derb]

yes, they do. if you can only do one antenna, a resonant dipole cut to length and 1/2 wave above ground is still the all around best if you have the horizontal space and the vertical supports on hand. Maybe on 160 not so much.

[KX5JT]

How does a dipole or inverted vee cut for 3.885 Mhz play on 3.690 Mhz???  I imagine a tuner would put it there right?

[N2DTS]

Yes, its what I like for the typical AM stuff on the lower bands.
I use a resonant (at 3870) dipole on 80, up about 45  to 50 feet.
I also have a fan dipole for 40 through 10 up about the same height.

Even though they are pointed east and west from South Jersey, they seem to get out.
No baluns, no tuners, no rf in the shack, they seem quite broad banded, whats not to like?

I dont have much coax on them, 75 feet for the fan dipole, 60 feet for the 80 meter dipole.

I had many qso's on 80 at 25 watts carrier without complaints!

Brett

[N2DTS]

If you cut it for say 3800, the swr will be quite low all over the phone band.
If you use a tube rig, it seems to be no problem at all.
If built right, fat wire and balanced, the swr will not go past about 1.8 to 1.

With good coax, on lower bands, and shorter coax runs, I dont think you get much loss at all in typical operation even with much higher swr.

Other advantages are, no power limit other than the coax, no weather changes to the swr, nothing to change, burn out, twist up, short out, fall off, saturate, plus it can be made out of almost any wire you have around.

I have spools of #6 copper wire I might try...

Brett

How does a dipole or inverted vee cut for 3.885 Mhz play on 3.690 Mhz???  I imagine a tuner would put it there right?

[Steve - WB3HUZ]

Mine is cut for 3.8 MHz or maybe a little higher. It is up about 80 feet. I've had no problem with it from 3675 to 3890 kHz. It is fed with about 150 feet of RG213. The loss at the frequency extremes is well less than 1 dB. I plan on changing the coax to LMR400 soon, so the loss will be even less.

Lower dipoles will generally show an even wider bandwidth.

[K1JJ]

Amen.

Yep, you can't beat a 1/2 wave dipole that is put up as flat and straight as possible -  and in the clear. It's all about pattern and efficiency.  The pattern is a nice figure-8 and the efficiency is right up there needing no ground radial systems.

The only way to improve on it is to add more elements (directors and reflectors) to increase its gain in one direction. The simple dipole is the basic core, the building block, of most all complex antennas.

On 75M, probably the best all-around dipole height for both local and farther out AM work is about  75'-90' high. This is difficult for most hams, so 50'-60' will do almost as well, especially for local work.

Those who have the room, but insist on putting up every other kind of antenna other than a simple dipole (as a reference) are missing out on one of the simple joys of life....

T

[W3DBB]

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