That's an amuzing idea. Imagine taking a 3 inch wide PVC or metal pipe of any length and filling it with earth. Mount the antena on the top of the earth-filled pipe and you've got direct contact with true ground, 20 feet up. 😉
YEs good thought, but a nice copper ground transmission line through it to ground level and a nice radial would complete it..
OK so 2 - 10 foot pieces of pvc pipe, with a nice thick copper line randown the center, filled with concrete for stability, joined together with a PVC joint.. that thing should be self supportive in burried into the ground about 5 feet, that would give you a 15' tower for your radial.. hardedst part how do you hoise up a 20 foot long tube filed with concrete... probably weigh about 300 pounds 🙂 Great idea if you got a crane..
How about building a tower out of copper pipe, all soldered together and radials aroun the base.. the structure that the antenna would be held up by and about the best huge ground system you coule make.. The Fcc would have to count it as the structure thatteh antenna is mounted to, your ground lead could be 2" and the rest could be radiator..
I kind of figured it out, i bought a 10 foot 1" copper pipe for $14 so eight of them, a bunch of couplers and joints t's ect, you could make a 20 foot tall copper tower out of copper for a coupe of hundred bucks.. Dang.. I may have to rip that antenna out of the ground now..
So How high of a copper tower can you make that will hold its self up.. Or how high can you make a signle coper pipe filled with concrete?? Add some guy lines.. I bet you could get a good 30 to 40 feet up with guy lines and a tower.. probably cost a god chunk of change but would get your signal up to a goot elevation and provide a awsome ground transmission line..
Maybe now that we think we have the best LPAM antenna wecan make we should try making FCC compliant big ass towers that are actually our ground..
Anyway my design is hollow, and all the ground radials converge inside the PVC.. All soldered together into a big wad.. It was super easy to build it this way and is rock solid, we had some decent winds today and the mast simply wiggles in the wind a bit.. Sweet
Jason
Anyone know how to get contact (preferably email) info for local FCC field offices? I'd like to ask someone at my local office how they interpret the part 15 rules - for example is the ground lead only that little connector to the water pipe / whatever I use for actual ground, or does it include everything above physical earth ground?
I think this would be good, but i also think that they leve the law open to interpritation, as this would allow them to shut down some one that is pushing the limits of the law...
So that being said if you can get your local FCC agents to OK your design, your probably good.. but others may be in a diffrent area that will interprite it diffrently..
I know of many cases where the structure is a ground and they ground the antenna to it and its not counted.. But there may be the ocation with a FCC pighead thatsays well its a ground so you have to count it your out of compliance.. shut down.. I think you could fight it if you had the FCC actually describe the law more so we would have definate guidelines..
My vote for the safest ground would be a big pile of dirt..
I would loke to hear the fact that you could build a copper tower 20 or 30 feet tall and be legal... If i knew for sure that it was legal I would definatly invest the cash into it, but it being in a grey area.. makes it a couple hundread dollar bet.
Jason
I had an email conversation with someone very knowledgable in radio theory and FCC codes. They had this to say:
An elevated antenna with a long ground run seems to be OK with
the FCC. They have given approval to many with elevated antennas. In
fact I have never heard of any problems with elevated antennas. Some
people have speculated that when you use a mast pipe or tower, only the
short length of the wire from the transmitter to the pipe/tower will be
counted as the ground length.In my mind this is just speculation. The ground part of the 3 meter rule is
too vague to be interpreted accurately making it somewhat unenforceable.
Whatever you decide to do will not endanger you of getting fined. The FCC
typically only investigates if someone complains to them. Then, if they find
any fault with your installation, they will first ask you to fix the problem
or stop operating (your choice). This is stated in the FCC rules somewhere.
This is enough for me to proceed with my plan to install the SSTRAN antenna on a mast that puts my system at roof level.
Regards,
Scott
Soon to be on the air in Omaha, Nebraska
Yeah the investment of a roof mount isnt nearly as big as a al copper tower 30 foot tall..
But a copper tower is so so tempting.. WHats the legal elivation limit before you have to put lights on a tower 🙂
I really liked your pix of your antenna. How is it working?
Neil
Well after the news abou the magnum having a few flaws in the design.. Im hoping there not to big but have no problems with building a second antenna.. But i feel that my design will work out as i can make mods to it to tune the mast and coil if needed..
And to top it off im strongly considering makinga copper tower 20 or so feet tall next year for the ultimate in tansmission range.. I then can make a better antenna if i feel this design antenna doesnt cut it.. but my goal range right now will most likly be covered by this design without problems if i make the mast adjustable, I took lots of time calculating my coil and making it as close as possable to the providedformula.. if that formula was correct.. the antenna should cover my goal of 5 block radius (my entire small town).. and it will probably hit the two farms out side of town.. there with in yelling distance on a quiet day.
Well I modded my transmitter and mounted it to my antenna, ran a really quick cat fice run for power and audio to my computer room where my studio... its 1130 pm and there is tons of crosstalk on my station at night.. so its not a good judge of my antenna. But I get my signal one block from my antenna before it becomes apart of the crosstalk.. I didn't tune it at all just slapped it in there and turned it on, as my multimeter is at work.. I do have to say just having a real antenna doubled the range over the tuned wire antenna.
Tomaarrow will be a much better test, I will actually tune my transmitter to my none adjustable mast an get some clear airwaves... then I should have a good judge of what this antenna does..
I do think I will need to convert the mast to be adjustable.. ths won't be a big deal and i will pick up the copper pipe and cap for that at lunch tomarrow..
I willfirst tune it to the non adjustable mast, and note its range then convert it to the adjustable one, and note its range and report back.
OK today after work as i aproched our town, i tuned my station to my station and as i hit city limits i heard the station fade in.. by the time i hit the first street that i could turn on to drive the outskirts of town it was lound and clear with minimal interfierance..
I drove around my side of town and i cover about 2/3rds of town.. this iswil my transmitter untuned, i forgot to grab my multimeter again , so im going to just buy a cheap one for around the house.. But this wont be till tomarrow.. I will then make my adjustable antenna then also.
I dont know how much diffrence tuning the transmitter to this antenna will make.. Maybee i will have my wife drive a block or two away and listen, and wecan jump on the cell phones and i can tune while she notes the signal quality she is geting.. Or i can wait until I get a multimeter tomarrow.
So my untuned transmitter on my non tunable antenn a made a range diffrence of about 10 to 15 fold.. over the wire antenna, not nearly a mile like many report, but a huge improvement no matter how you look at it.. as i see it if i make my mast and do some fine tuneing i will easly cover the entire town with strong signal..
Keep in mind my town has a population under 60 people, but gets lots of drive through traffic.. the town covers about 15 blocks,, 3 blocks deep, by 5 long..
I will report back when i change more stuff.
Jason
Way to go on your signal test. I trust tuning will help. One word of advice...you mentioned getting a cheap meter. Get a digital meter and if possible make sure the input impedance is 10 Megaohms. Some of the cheapies are 1 Mohm impedance. They will work, but the numbers you get will not agree with the SSTRAN instructions.
Please keep posting your experience. I am interested because I am running on an indoor antenna in my basement under a stucco (with expanded metal base) house. I still get out about 500 feet. I have a base loaded vertical under construction, but probably won't get it finished for a while. I just would like to know what improvement to expect before I start digging.
Good luck.
Neil
Hi Neil:
I'm also building the SSTRAN antenna. Just tonight I've been trying to cut the 3" deep cross into the end of the 10"L 3/4" diameter copper pipe and having the hardest time.
My cuts drift and end up causing the four tabs to be off so that the two don't slip over the other two when I try to tighten it over. Instead I get one tab that slip over its neightbors, and only one side of the remaining tab slipping over, leaving one joint with its parts just butting up against. (Step 8 under Antenna Construction Tips).
I've tried it with two pieces of pipe, with one result better than the other. I've only got one piece of pipe left. Does anyone have any tips? Maybe if I did a half-inch at a time and then made the other cut, I could work my way down a little more true.
Regards,
Scott
Hi Scott,
I got that part done and it works great. Here's how I did it:
I have a little Delta bandsaw and found a metal cutting blade for it. I used the guiide fence and sawed away. The overlap was fine and the clamps securely hold the assembly together.
Other ways to do it would be to lightly clamp the pipe in a vise and use a dremel cutting wheel. This is tricky and dangerous as the dremel wheels are very prone to breaking. If you try it, make sure you protect your eyes.
In the old days, when all I had was a hacksaw and a vise, I would wrap the pipe with several layers of masking tape. Use a fine toothed blade and go slowly. The tape keeps the blade from slipping.
Cutting straight cuts is always a problem with hand tools. It will help if you use the tape method if you just do one cut at a time and keep the blade angle very small, almost parallel to the pipe. With the tape you can probably get a pretty straight cut.
When you clamp the pipe in a vise, don't clamp where you are cutting. Leave the 4 inches or so sticking out of the vise. Otherwise, the vise will squeeze the blade and you will get nowhere.
Hope this helps. Let me know.
Neil
Scott,
I should have mentioned this but missed it in my post. You said you had only one piece of pipe left. Don't worry. If it is a little short because you have to cut off the bad end you can just make the 1/2 inch piece a little longer. Just keep the total length of the 3/4 and 1/2 the same. If you lose 4 inches on the 3/4 just add 4 inches to the 1/2. This gives you several tries to get it right.
Maybe you should try my tape method on your scrap piece first, and if it works, go for it on your good piece.
Neil
Well today i tuned my antenna, with the non adjustabe mast.. I could not get ober 8 volts on the multimeter when testing (i barrowed my dads meeter).. So I decided to hack off the mast and make it adjustable..
After having on the top and making the new adjustable mast, I was able to peak it at about 10 volts.. while transmitting a good signal..
This is getting me a great signal 2 blocks away and a listenabe signal 1/3 of a mile away.. this was done at about 2:00pm while the bands were clear from bounced signals..
Now at 6:00pm the signal get broken up a pretty easly.. but still cobvers most of town..
So Im getting about 1/3 of a mile. form this..
IF i had more time to test i would put a test tone on so my metering would be easier to do.. I think i can tweak quite a bit more ti get this signal a 1/2 mile ut wih out any problelm..