I also have to add, the wires can become quite tangled easily while putting it up, unless you put physical spreaders in. Other than the mistake with the MFJ unit, that was the most difficult part.Quote:
Originally Posted by KU0DM
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I also have to add, the wires can become quite tangled easily while putting it up, unless you put physical spreaders in. Other than the mistake with the MFJ unit, that was the most difficult part.Quote:
Originally Posted by KU0DM
Yes, that MFJ-269 is one of the best things since sliced bread. I'll never be without one again! One tip for it. Get an unused power connecter for the ext. power in jack, and leave it in the jack when you're not using the '269. It'll act as a "safety" and keep the power OFF. The only thing I don't like about the analyzer is it's easy for the power button to get pressed and run down the batteries. But this trick takes care of that nicely.
OK. We're talking about dipoles and tuning them, and pruning then, and using multiple dipoles on one piece of coax, etc., etc., etc. Look out, here comes my usual :rant: on the :soapbox: ! ;)
Last year doing the hamfest circuit I saw the small Johnson matchbox several times, and the prices were always < $100. I got one without the meter and other stuff -- but with the tuning network clean as a whistle - for $50.00. Here's why you, too, want one of those.
With one of those, or maybe better yet, one you've built (they're easy and cheap to build here's K1JJ's outstandingly easy and effictive design), you NEVER have to prune you antenna. You HARDLY EVER have to worry about "RF in the shack", and you'll have a very easy and effective antenna. The length of the antenna becomes completely non-critical -- the rule of thumb is that any length greater than or equal to a half wavelength on the lowest frequency of operation works just fine -- so you can measure your antenna, put it up, and be done with that part. Plus -- if you want to do an extended Zepp (fun to play with) or a lazy-H (even more fun to play with), the tuner'll tune that, too.
You MAY have to tune the feedline. Impedance varies all over the place depending on the length of the feedline, and it can be tedious to find the length that's good on all bands that you want to opearate but that's a heckuva lot easier than pruning an antenna. And once you've got it, you're done.
Over the years I messed with tuned dipoles, sometimes with frustration, etc., and it took me a good 30 years to get the above about balanced line and link-coupled tuners through my thick skull. What a pleasure putting up a dipole became when I finally "got it!".
Finally, much as I post against them, a "fake" balanced tuner (e.g. single ended with a balun) will do nicely in a pinch. That's what I first used. It's not optimum but will tune a balanced antenna and won't eat up enough power to detract from your fun!
OK....off the soapbox!!! Have fun!!!!
I've been using a balanced tuner I built from specs in the Handbook (I think it was). Anyhow, pix on "that other site".
http://www.miracleantenna.com/MMD.htm
Just use the Miracle Antenna!
They even have video!
http://www.miracleantenna.com/Miracl...a%20Videos.htm
G'day Corey....I wonder if you have considered using a 40 meter dipole fed with 1/4 wavelength open wire feeders and a balanced tuner? With this set up you can then tune 20, 15, and 10 meters....Probably also the WARC bands as well....No more wire tangles and sorting out each antenna with the coaxial fed fan....Many of these old ideas have been lost in recent years and yet it is the simplest way to get on multi bands with the least bother....I would look at building a link coupled tuner....For 40-10 meters a simple inductor say 12uh, a parallel 75pf transmitting capacitor if you run more than 100 watts, and a few turn coupling link over the center of it with a series old 3 gang broadcast gang...You could breadboard this with a few alligator clips to select tappings for each band and you have the world at your feet...The 40 meter dipole then becomes 1 wavelength at 20 meters and so on up the spectrum...No more multiple wires all over the place..:chin:
Bob..VK3ZL..
If you live in a multi story building and don't have a good earth connection it is a good idea to run a 1/4 wavelength of wire from the earth connection on your radio gear around the skirting or anywhere you can conveniently lay it....This will help eliminate RF feedback and other problems....Toss it out the window or stick it in the bathroom...Endless possibilities....
Bob..VK3ZL..
We don't agree on much other than art, tank circuits and antennas Bob.:lol: I guess that's enough.Quote:
Originally Posted by VK3ZL
Open wire feeders and balanced-balanced tuners seem to be fading in popularity among all but the older hams. Why? I have no idea.
The concept of proper RF grounding as opposed to proper home AC distribution grounding is another sticking point that most seem incapable of grasping. Combining those functions is an invitation to problems.:irked:
Fixed my wind damaged open wire connection this afternoon.
It does amaze me that more folks don't do the "all band" doublet (or OCF) with a tuner and balanced line... balun or no.
Easy peasy antenna system. :dance:
Been considering the folded dipole for 20m with the legs added for 40m.