I had an old CB 5/8 wave antenna back in the day and got to thinking why not have a ground plain on our AM part 15 antenna's like those old CB Antenna's ?
I had an old CB 5/8 wave antenna back in the day and got to thinking why not have a ground plain on our AM part 15 antenna's like those old CB Antenna's ?
Would this put us out of spec for part 15 ?
I'm not saying use a 5/8 antenna from cb , but design an antenna with ground radials that would act in the same fashion as a CB Antenna .
What do you all think?
I am not really a bar fighter but I want a tough persona when I insist on this opinion and refuse to listen to any other points of view.
I believe that a ground plane like that on a CB antenna is legal and meets the spirit of the part 15 rules.
I believe the CB-like ground plane is no different than an under-the-earth ground plane, but without the mud.
There should be a minimum of two ground horizontal planes, facing exactly 180-degrees from each other, so that they do not radiate, but cancel each other out. Four ground-spokes is more common in the CB design, and that's fine.
But here is what gets sacrificed...
On the AM band the ground radials should be 30-feet long APIECE, for a total reach of 60-feet. This would be hard to achieve standing up in the air above the ground.
And the best number of radials is 64, which would make a very wicked CB style antenna.
But your original question, is a CB like ground plane legal for part 15 AM?
I say YES.
Yea Carl I don't want to be a bar fighter either 🙂
Well at 30 feet I guess I would have to forget this idea LOL.
Perhaps we can use a coil to achieve the length for the radials ?
So perhaps we could use five foot radials and then use little loading coils to make up for the short length.
Just a thought.
reason I am looking at this , is my second transmitter may be a SS 5000 .
Thanks again for the post.
BTW Love the low power hour, I listened to the first one last night and I have to say that is they kind of show I was looking for.
very informative.
Experimental, real-world results going back many decades prove that an elevated vertical monopole driven against two or more 1/4-wave, symmetrically-arrayed, elevated, horizontal conductors used a counterpoise is the electrical equivalent of that same monopole with its base at the surface of the earth, and driven against an r-f ground consisting of 120 x 1/4-wave buried radials.
This result also is confirmed by MoM software models comparing those systems.
Mr. Lefty Gomez, hold on. Don't leave yet.
Your idea of ground radials being connected to loading coils to increase their electrical length is novel to the point of being Nobel Prize material.
Those of us who are out of control electronic freaks of nature would go wild having 60 or 70 giant coils out in the back yard.
I am not kidding.
This is stay up all night kind of stuff.
Is this type of ground basically a set of radials attached to the tower above ground? I'm not sure because I'm so new to radio, but I am very interested. It would be neat to have above ground radials, if that's the case of this setup.
If possible, could someone post a link to this kind of CB setup so I can get a picture in my head.
Here you go X1610
Hello channelx1610 and hold tight...
Your question is excellent , but I myself will not attempt to answer it now.
I am here to say that "Yes," above ground radials are everybit as possible as below ground radials.
But it has to do with length.
For CB the radials are conveniently short.
But for AM they need to be very long, which creates huge management problems if they are above earth.
But it is possible.
Keep digging. Above ground. So to speak.
just starting to investigate it right now guys !
MRAM is also on the trail of investigation on this concept.
I am thinking Loading coils might work.
More info coming.
I've read articles regarding loading coils used as part of a counterpoise or artificial ground system.
HERE IS A LINK to an article that leads to some info about just such an idea.
Also, somewhere around here I have an ARRL antenna book that addresses the idea. I'll see if I can find it.
An internet search of this topic yeilds links to several articles.
MRAM this notion of loading coils on radials AND on antennas is a whole new day in the part15 saga.
While the actual result in terms of distance covered might only be a matter of inches, don't you think we will go for it in a big way?
I am already considering gardening arrangements based on a "splash of coils" situated back in the back.
I never kid.
Just as having to put a coil into a too-short antenna ruins its' efficiency, putting coils into too-short radials ruins the conductivity of the system as soon as you get beyond the actual legnth of the radials. It would perform much better than having no radials at all, but not nearly as well as full legnth radials.
If coil-shortened radials were as effective, it would have been done by the big boys decades ago to avoid having to have all that acreage for full-sized ground systems. Sorry to burst any bubbles, but AM antenna theory says this is not a good way to go.
No bubbles bursts here 🙂
theory is just that theory .
The Bumble Bee can't fly either , So I will experiment and fill you on the theory.
Never the less after reading up it looks like I can build one.
Will let you know what goes on as the project moves forward.
Someone once told me an aluminum Christmas tree was useless beyond the holidays.
Upside down it can do some amazing things in MW. 🙂
RFB
🙂