I just was re-reading a post I made earlier this year and some of the helpful comments many of you made about my problems with getting any real range at all with my current Rangemaster setup(against the back side of my house). The common thread was build a much better ground system, which I am finally getting around to doing. But not being an engineer guy, I can't at all visualize most of the suggestions, particularly about a radial ground system. Currently, not knowing any better, I have my ground going down vertically from the rangemaster(20 ft or so in the air) into the ground at the base of my pole and then it goes about my 100 feet or more horizontally in my back yard(maybe a few inches below the surface or as Rangemaster's website suggested).
Would anyone have a basic graphic that could post of a basic radial ground setup? Or at least a very basic description? I am particularly confused as to how all the ground wires in this radial design meet up at the base of the pole. Do I need something(metal object?) to attach them all to the mother ground wire(as I described in the above paragraph)? Describe it like you're talking to a 5 year old. I don't mind 🙂
Thanks in advance.
Here is a link to a Techtalk Article from the ISS website regarding groundplane (radial) system.
They show how their groundplane system is constructed and how it is implemented. It should be a good visual for you.
The link in the post above should answer your questions. It is usual for us to use about 10 or 12 radials but more wouldn't hurt.
Just a note on how they operate to help you understand what they do. The vertical radiator induces currents in the soil which need to be returned to the transmitter ground. Each radial collects a portion of the current and provides a low resistance return path to the transmitter ground. Since a particular radial conductor has a "mate" 180 degrees around the circle the two have equal and opposite RF currents whose radiated fields cancel so the radial system does not radiate.
There is still current converging on the transmitter ground without the radials but this has to traverse the high resistance soil which results in power loss to heat.
Neil
Neil that's a wonderful explanation.
You and some of the other guys here
not only are great engineers, but also
really good writers.
Best Wishes
Bruce, MICRO1690/1700
Thanks for your responses. Can amatuer's like me purchase and install ISS's Powerplane system for Part 15. I don't see it listed in their catalog. Or would be just as easy if I just made a circle of the #8 wire I bought(that Rangemaster advises)?
Hi Chuck,
You can make your own radial system if you choose or purchase it from the Antenna Guy (Carl) whose site is linked from the SSTRAN site. Click on the SSTRAN logo on the left panel and look for "Pre-fabricated coil and ground radials". The SSTRAN site also includes other information about building antennas as does Carl's site.
The ISS system, though intriguing, appears to be more than is needed for a good part 15 system. You could get some #12 wire at the big box home improvement stores and work with that. 100 feet would be enough for 10 radials.
Theory tells us that larger wire is preferable due to the "skin effect" but #12 should work fine and save you money.
You just need some good plans and you will find radials are easy to construct. You might also search this site using "radials" or "antennas" for key words. There have been many posts on these subjects.
Neil
Chuck,
Your ground system uses a single radial near the surface of the earth. What the people here are suggesting is connecting more radials to the bottom of your vertical wire, going in other directions. Your single radial is 100 feet long, but the others can be shorter, but at least 30 feet long. Add as many radials as you can. You don't need thick wire, which is very expensive. Any wire will do.
The system you have now should give good results. Your problem may be that your vertical wire is too close to your house. Since you have a 100 foot radial, there must be room on your property to move your installation away fron your house. This may not be easy to do, because you need to construct some other way to mount your transmitter.
Another possible problem is that your area may just have too much electrical noise for good AM range. It is not easy to find out if this is the case. You might try contacting a local AM station and see if the engineer will to talk to you. The people at some stations are hepful, but not at other stations. If the ambient noise level is too high, there is nothing that can be done about it.
BTW, thanks for taking down the Nikita picture.
Thanks again for so many helpful suggestions. As cold weather season is fast approaching I'm thinking for now I will use the additional $100 dollars worth of #8 wire I bought(as Rangemaster's website advises) and cut it down to several 30 feet or so strips and make a radial system as suggested. I can always move the antenna away from the house in the future(will be tough, but doable).
Questions:
If this doesn't help much, perhaps I will then look into buying that ISS system and results still aren't up to par, I will consider moving the antenna away from the house.
Does this sound like a plan to all of you?
Most info I have read on ground radials suggests that insulated wire is OK. They go on to say you shouldn't bury it too deep as that will increase losses. Some individuals simply "pin" the wire to the ground every so many feet and let the grass weave it in. Once it's embeded in the grass it's not likely to get caught up in the mower if secured.
If at all possible move the antenna away from the house to allow the radials to be extended away from the base a minimum of 10 or 20 feet in all directions as ISS suggests (depending upon your frequency of operation.)
How is your antenna mounted, on a tower attached to the side of the building?
My antenna is on my roof. I installed 6 #18 radials each about 15 feet long spaced evenly around the base of the antenna. It did make a difference and I'm sure more would be better.
At these frequencies my feeling is that height only increases range due to the long ground wire which acts as part of the antenna. In my case, the antenna is about 30 feet above ground and the "ground" connection to the radials is only about a foot. Even though the coax from the transmitter to the antenna is long, the radials made the difference.
"I just was re-reading a post I made earlier this year and some of the helpful comments many of you made about my problems with getting any real range at all with my current Rangemaster setup(against the back side of my house)."
Can you post a picture somewhere? If not email one to me and I'll post it.
Anyway, some of your problem might be related to the position of the Rangemaster system. My experience is that antennas where the radiating element is in too close a proximity to a wall, or even a metal gutter, can cause problems. It depends on the materials the wall is made of and/or what's in the wall, and how much antenna is above the top of the wall. For example, if you have aluminum siding, as much of the antenna as possible should be in free space ... at the very least 60%. Even then, if it is in close proximity to the wall, it could be getting too much reflection from the wall. Your propagation pattern would be fouled.
Further, if the antenna was tuned in a different position, i.e., moved after tuning, it will likely be out of tune and won't resonate. Antenna systems need to be tuned in their final position.
As to grounding, it is critical in AM systems, the better part of how they work in daylight hours. A good ground system doesn't mean a lot of wire just under the ground. E.g., a Rangemaster, as I understand it, needs to be grounded to something that goes deep. That may mean creating a separate ground for it right under it, i.e., a grounding rod (or two, bonded) of at least 8 ft., into the ground. IOW, your long wire isn't doing much to ground your system, unless it's connected to something that is, like a metal water pipe, and not one that is connected to PVC under ground ... because PVC does not conduct, or a ground rod.
HTH ...
Ken - I sent you a pic of the system. Yes, feel free to post.
I do have a couple ground rods as part of the underground horizontal ground system, one of them right at the very end(as suggested on Rangemaster's website). I also buried various metal objects in ground along the route.
You'll notice from the pic that the antenna is set up along the one story add-on to my 2 story house. As the antenna system is surrounded by wide open spaces in all direction, that might be ok? or no?
...ALSO, the add-on has only a crawl space underneath. I think I could bury the radials in going in that direction into the crawl space. That might be acceptable?
I have a "postage stamp" lot, so I'd prefer to see if I can first results from the antenna in it's current position, before moving it somewhere else. Also, at the end of the backyard(opposite side of the house) are large trees, so that's probably not a good place?
Chuck
This is a nice approach and cost effective.
http://andrewgump.com/antenna/Radial_Images/Pages/Radial_Setup.html
Interesting. Unfortunately for me, the text is in spanish. All those square shaped metal objects - those appear to be what you connect the many grounds wires - that is, at the base of the mask, where the vertical ground wire meets the earth(& then goes horizontal under the ground)?
If this is what I need, where do I purchase one?
May I suggest DX Engineering as a starting point. They manufacture and sell antenna ground system components that are worth the coin. You can find them at:
You will also find tutorials that explain how to use these well made tools and components.
I didn't get a picture. Never had problems before, what emailer are you using?
Anyway ... "...ALSO, the add-on has only a crawl space underneath. I think I could bury the radials in going in that direction into the crawl space. That might be acceptable?"
It needs to be directly under the center of the antenna, nothing in between. In re-reading your original post, you indicate the system is on a mast attached to the back of your house. How will you distribute ground radials directly under it? If half of them in the circle of radials go under the house, then the whole rest of the house is above that section, and surely would prevent it from working properly on that half.
"I have a 'postage stamp' lot, so I'd prefer to see if I can first results from the antenna in it's current position, before moving it somewhere else. Also, at the end of the backyard(opposite side of the house) are large trees, so that's probably not a good place?"
Some longwire antennas are actually set up in trees 😉 Anyway, I think I understand your dilemma, but what we've been saying is that, back yard size not withstanding, the system should be mounted in the center of your yard with at least 10 ground radials (you can always double them later) @ 10ft each (or as long as will fit in even lengths) directly centered under it.
A design I haven't had time to build out has two concentric #6 bare copper wire circles, one @ 3ft. dia., the other @ 4in. dia., with heavy copper screen between, trimmed to fit and soldered up, one bronze ground clamp on the inside circle for the antenna ground wire, another larger one for a ground rod, and a bunch more smaller clamps 'round the outside circle for the radials. The idea is to provide both a dense ground plane near the center and a stable fixture for attaching the radials in one unit.