What Is It Called?

[KG4CGC]

Good Day Everyone.
We all recognize a doublet dipole, correct? What I am about to describe is similar but with one major difference.

Take a piece of TV twinlead and cut it to a half wavelength for say, the center of the 20m band. Remove a half inch of insulation from both ends, twist leads together and solder.
Locate the center of the length of twinlead and remove a half inch of insulation from only one lead, cut single lead in center and connect this to a quarter wavelength long length of twinlead.

What we have here resembles a dipole but I'm having difficulty looking it up because I don't know what to call it. A flat loop? The reason I find the design interesting is because I wonder if it will work for a 40/20m set up where the antenna described above is the 20m meter section and then add a single piece of wire to each twisted soldered end to extend the resonance to 40m.

I was discussing this yesterday with an Island member but when I said doublet, I really meant the design described above.

Thoughts? Opinions.
The cold hard facts?

[N9FE]

Folded dipole ?? Don't know :oops:

[KC2UGV]

Sounds like a folded dipole to me.

[WØTKX]

http://www.radio-electronics.com/info/antennas/dipole/folded_dipole.php

Folded dipole, greater bandwidth, 4x typical dipole impedance. Normally you don't wanna add wires to it, but it might be interesting.

Is this for you?

I'm going to be making major antenna metamorphoses in the nest few weeks. Could be a fun thing to do in the projects thread. I'm a huge fan of the 80/20 % OCF dipole, but loops may be better, even if weird and misshaped.

Maypoles are pretty interesting as well...

[KG4CGC]

OK. Good, I looked up folded dipole and it seems to fit the description. Excellent! Yes, I should have thought of it but when CRS kicks in, it kicks in until someone knocks out that brain fart.

Now how would it act with the attached wires on the ends to attempt dual bandedness?

[WØTKX]

Well, there's linear loading, and it's tricky... but there are some amusements...

http://www.g4ilo.com/watson-80plus2-antenna.html

http://www.vanyi.net/homemade/antennas-hf-vhf-uhf/

http://www.vanyi.net/wp-content/uploads/2009/10/linear-loaded-dipole-for-7-mhz.gif

http://www.hamradiosecrets.com/short-ham-antennas.html

http://www.hamradiosecrets.com/image-files/short-ham-antennas-hf-dipole.gif

[N9FE]

Sometimes even a farmkid gets it right..

[KG4CGC]

Nice article Dave.
Can a 20m folded dipole act as a 40m dipole when the single wire legs are added to each end?

Once it goes up, it's up.

[N9FE]

A folded dipole is usally one banded. A Fan type dipole is multibanded. You can try. But i think you will change the performance on the band your shooting for by adding wires..

[KG4CGC]

A folded dipole is usally one banded. A Fan type dipole is multibanded. You can try. But i think you will change the performance on the band your shooting for by adding wires..
You're probably right but I was wondering if there was some special magic "in the fold" that would work in my favor.

[WØTKX]

I love antennas, especially wire ones. It blew my mind forever, when I put my first SWL antenna up, outside. That's something pretty wild when you're about 10 years old. A good wire antenna will make me feel almost homesick. Grin stupidly at the sight of balanced line. :D

Umm, whatchoo trying to do Charles? Focus on 80 and 20? All band inspirations?
How about "all band", as low as you can go? What's your tuner situation, as in do you have one? A balun?

I'd bet the output of the FT-901 will be able to deal with some impedance mismatch.

It's time we got some Island Ragchews going. What's the population skew, mostly East and South East for the Island regulars, right? One of my goals is a wire antenna that favors that direction, I have no problem going west, even barefoot.

Flame On, Torch!

[KG4CGC]

I'm planning on replacing my 80/40m with something more robust, mechanically.
This antenna however is poor for 20m. so, I want to put up another antenna made mostly from TV twinlead for 40/20m. This will be used on 40m at times, different directional pattern etc. For 15/10m I will use an Antron with tweaked radials.

[WØTKX]

Do a fan dipole for 80/40/20. That should cover most of what you want to do. But again, with a robust tuner situation, the antenna can be simpler...

http://www.hamuniverse.com/multidipole.html

[VE7MGF]

http://www.hamuniverse.com/cobraantenna.html
if you have the space this might work for you

[KG4CGC]

http://www.hamuniverse.com/cobraantenna.html
if you have the space this might work for you
Nice idea! I actual put one of those together in my head but didn't know where to start in applying the math. i could probably fit it in by making one leg an L ... Well, both legs would come out that way when all is said and done.

I just want to thank everyone for all their responses!

[N9FE]

You gots to have lots of room my friend. And tuning is a bear. The leg spacing is critical. But you can do it.. Edit: Don't cut ANYTHING til done. Just keep folding back and taping till all are tuned !

[w3bny]

I just run 137' of oh..#6 stranded copper...(it fell off a truck..capice paisan!) fed with 400 ohm to the house...1:1 baylum and RG-8 to the box. ends..uhh.. North to south.

[WØTKX]

Simple works really well, doesn't it? :mrgreen:

[N9FE]

Thats what i have here 135 feet. 600 ohm right to the tuner. Works like a dream.

[N8YX]

I would put up a perverted Vee...

Get an Alpha-Delta DX-DD 80/40 "loaded" dipole (or make your own variant), add a couple of wires for 20M (spaced ~6" away from the 40M wire) and tune the 40M section for resonance at ~7.100MHz. That way you'll cover 15M with a resonance "dip" at ~21.350. Tune the 20M wires for 14.200 and it'll be under 2:1 across the band...not that a tube PA really cares much!

Lastly, you adjust the "ends" for whatever 80M frequency you favor.

Mine has its apex at ~45ft, is fed with LMR400 and has 10 turns of the coax in a 6" diameter coil at the feed point to act as a choke.

http://www.alphadeltacom.com/images/Image32.gif

[KG4CGC]

The 80/40m will be fed with a choke. The folded dipole will be fed with a quarter wave of twinlead that connects to a balun that connects to coax to the shack.

[N8YX]

So....ahhh...barkeep, have you gotten anything in the air yet?

Dave: What's the status of your '902? Is it ready for air play?

Sounds like we have the makings for a nice vintage Yaesu round table here. :think

[KG4CGC]

So....ahhh...barkeep, have you gotten anything in the air yet?

Dave: What's the status of your '902? Is it ready for air play?

Sounds like we have the makings for a nice vintage Yaesu round table here. :think
I have the current 80m ant that is resonant at about 3.6mhz. The homemade choke is resonant at 6m but I think that signal goes straight up. I want to replace this antenna but it did go West to about Dave's territory on 65 watts. SSW and NNE it was very strong. I will use just about the same set up but with heavier wire and a higher feed point. I also want to get the highest point of the antenna up higher. All my good woven nylon rope is gone though, fishing in the mountains off steep banks one season, so I will need to pick up some more of that.
Fling fishing line over trees. Pull rope up through flung path. Repeat process over next sections until the rope path is laid out. Attach wire to far end and pull. I may have to set up a support mast in the front yard where the bird feeders hang.

Last week my GF brought home an above ground pool, used, so guess what gets priority? The algae was a beautiful shade of green.

[WØTKX]

Stay buff, poolboy. :rofl:

[KG4CGC]

We'll see how all the dog walking works out. Oops, time for oatmeal.

[WØTKX]

So....ahhh...barkeep, have you gotten anything in the air yet?

Dave: What's the status of your '902? Is it ready for air play?

Sounds like we have the makings for a nice vintage Yaesu round table here. :think

I have not even started on the 902. Antenna projects are more pressing, but I did get the scope, and I need to get the driver tube tested, I already tried a known good 6146.

The radio deserves a thorough going through, but it seems to receive just great. I have to look and see if it has the 6KHZ AM filter in it, and want to use it on AM. But I refuse to get a wowipop mic. :rofl:

I am pretty casual about my Ham Radio projects these days. Still skiing and motorcycling. Yard needs a ton of work. Eh?

[N8YX]

Last week my GF brought home an above ground pool, used, so guess what gets priority? The algae was a beautiful shade of green.
Keep your pool hand strong...

[KG4CGC]

Last week my GF brought home an above ground pool, used, so guess what gets priority? The algae was a beautiful shade of green.
Keep your pool hand strong...
:rofl: :rofl: :rofl: http://i25.photobucket.com/albums/c79/bebop5/icon/g-DumbBell.jpghttp://i25.photobucket.com/albums/c79/bebop5/icon/g-BarBall.jpghttp://i25.photobucket.com/albums/c79/bebop5/icon/g-MuscleMachine.jpghttp://i25.photobucket.com/albums/c79/bebop5/icon/g-GymBike.jpg