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Everyone is searching for the holy grail of Part 15 AM transmitter installations. It’s all very simple. A base-loaded vertical is the time honored and proven best antenna. Stop fretting about top-hats, center-loading, etc. They don’t help much and are either legally questionable or physically impractical. Prior to the (redacted – let’s not discuss people who aren’t participating) era, the easiest way to dramatically increase your range was to elevate your transmitter/antenna to 20ft or 30ft or more. Now, we can only fall back on stretching other parameters to compensate for the loss of height. Ground Radials: antenna modeling software shows a dramatic improvement in field strength for a ground-mounted 3m antenna when you install 32 to 64 ground radials at least 30 ft long (ouch, pain, chiropractor…) Loading Coil Efficiency: when the antenna radiation resistance is only .1 ohm, the MAJOR loss is in the loading coil. Typical “good” coils have a series resistance of about 15 ohms. This “huge” resistance is the overriding factor in determining overall loss. Any incremental improvements of the antenna (like a top-hat) will only increase the radiation resistance by another .1 ohm or so. The holy grail here is to find a way to reduce the loading coil resistance. A big air-core coil is the best possible. It can cut the coil loss to as little as 5 to 10 ohms. (again… ouch, pain, maybe not a chiropractor). It seems to me that the masses are always brainstorming oddball antenna alternatives rather than focusing on the real agenda. The brainpower of the masses would be much better spent on how to reduce the losses of the loading coil. That’s not as much fun as imagining the result of using an upside-down mailbox as the ultimate antenna, but it is reality, not fantasy.
Total posts : 45366Not to stir up a hornets nest..but I have to reply to this blah blah nonsense…for the sake of learning and experimentation and the HOBBY. And this is with all due respect.
Stop fretting about top-hats, center-loading, etc. They don’t help much and are either legally questionable or physically impractical.
Something bother you about others trying their own created concepts that you have to come here and thump bump their enthusiasm with this so called time honored crap?
There has been ENOUGH of “don’t do this, don’t do that” time honored BS nonsense. You know why don’t we all just give up our individuality and become clones or Borg’s or ants and form into a colony doing only one thing across the board! Serve the Queen. No thanks.
How about a little more enthusiasm about the HOBBY. I get so sick and tired of all these nit pick blow hard so called experts dogging down people all over these boards when all they want to do is to expand their knowledge and learn.
There is this thing called “Freedom” and “Independent Thought” and “Individuality”. A time honored and once respected and recognized tradition.
It seems to me that the masses are always brainstorming oddball antenna alternatives rather than focusing on the real agenda. The brainpower of the masses would be much better spent on how to reduce the losses of the loading coil. That’s not as much fun as imagining the result of using an upside-down mailbox as the ultimate antenna, but it is reality, not fantasy.
OMG!!! What a crock!!! I wonder if Marconi or Tesla or Einstein had to endure such bull stink. If they did….did that stop them? Hell no! And your nonsense should not stop those who are here to discover and find different and UNIQUE ways outside of that so called time honored tradition. Wow imagine…if everything stayed in one place due to limitation of time honored tradition…we would be exchanging all this lovely commentary via smoke signals and air mail via pigeon express.
And suppose everyone did focus their collective thoughts on reducing losses in loading coils. What kind of contribution would you have at that point given the contribution example your giving now??? What…we would be wasting time on pointless efforts there too??? ROFLMAO!!!
If their experiments work…fantastic! If their experiments do not work, so what? Does it affect your wallet or precious time spent on going around quoting time honored riff raff?
Here is a clue…the best teacher in learning anything is by doing. There is only so much that can be done on a piece of paper filled with theory. If someone engineers the ultimate mail box antenna and manages to make it work….do not worry friend…your world is still intact.
(redacted – let’s not discuss people who aren’t participating)
This is about a hobby, where experimentation is the heart of it and learning about radio..regardless if it works or not.
Afraid of someone actually discovering something that does go beyond that 8×11 world and may prove the number thumping wrong that rips them legs right out from under the cloud 9 perch?
Well by golly gee whiz plop plop fizz fizz man. I’m sorry that freedom of experimentation is such a thing that would upset time honored nonsense so badly that the only relief it is would be to number thump everyone in attempt to convince them they should limit themselves to equal a self inflicted boundary so as to feel comfortable and confident that no one could possibly surpasses it.
That post up there of yours, in my individually inspired opinion, is not worth the web space it is occupying. If you don’t have anything to contribute to the efforts other than the same ol stale rotten garbage, then please spare us the howdy doody puppet dance. The tap tap of the cane on the floor is disrupting the flow of thought as well as discovery.
With all due respect…
RFB
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Total posts : 45366I don’t believe that smoke signals and airmail pigeon express are part15 compliant modes of broadcast.. unless a means is provided to insure the smoke does not rise above a 3 meter elevation, and the pigeons are equipped with a ankle bracelet attached to a 3lb weight.
But seriously, what’s the problem between you two guys?
Presto!, a argument over nothing.Relax… have a coffee, doughnut, cigarette, cocktail or whatever floats the boat, everything is cool.
Total posts : 45366But seriously, what’s the problem between you two guys?
I have no problem, none at all. I am simply expressing my thoughts in respectful reply to a post about us wasting time trying unique ways to do things. I find the poster’s post to be totally against the spirit of experimentation and discovery of the hobby we all enjoy. Nothing more.
It is an agree to disagree point.
Now I will go enjoy my cup of coffee and doughnut and cig and ripple the waters of the health nuts because I have the freedom to do so…at the same time I will be constructing that unique upside down mail box antenna just to exercise my freedom to mount it upright or sideways or hang by a rope off a daisy over a cliff. 🙂
RFB
Total posts : 45366Well, I think Phil IS right about the loading
coil, and HI Phil from me – one of the guys out
here! I am a big fan! And I’m sure you have
seen what some what some of the
LONGWAVE Part 15 people are doing with
coils, it’s unbelievable!The thing is – right now with all the stuff I have
going on – it’s actually easier for me to mess
with the antenna, that’s all. It will probably
be crude and may mot even stay up in
the air very long – but I am more of an
experimenter than a broadcaster.I would love to build a huge air wound
col, but that takes money. I actually have
some materials here to try this antenna
thing so I’m just going to try it.And to RFB, you have given me TONS of great
info, which I have enjoyed very much, and I
have learned a lot. And the solar power info
you gave me is great. I didn’t have a clue.So there it is. You’re both cool guys in my book!
Best Wishes,
Bruce, MICRO1690/1700
Total posts : 45366The guy that rhymes with Pie must have blown the whistle on someone with a high placed antenna and got them shut down. That would explain everything.
“If you see anything, say anything” – Dept of Homesick Sickurity
Total posts : 45366Well, I think Phil IS right about the loading
coilI do not discount Phil’s notes regarding loading coils. All kinds of different ways to create those things besides the “honored tradition” of wound in a drum configuration.
What I point out is that in order to experiment and even find that ultimate loss-less coil is to think outside of the box. Not much more can be found when you limit yourself within borders and explored every square inch inside. The only result from that is finding the same results as found previously and nothing is really gained from it except knowing what you already know.
Makes sense doesn’t it?
Ok so we know the limits of this and that. Been pounded to death so much that the stale dust is the only thing coming from it. So how do you find that new frontier?
I would imagine its by going beyond what is already established. That friends is the key to discovering new ways to do things. Who says you have to stick to ground level on the foundations when the intent is to rise to new heights?
Think about it.
RFB
Total posts : 45366Here in the chamber of my transcendental court, I have taken all sides under advisement and am prepared to issue a ruling.
I believe that both sides are right.
PhilB is right because he is taking the position of the known and established method for achieving the ultimate result on part 15. Proven science.
But the open minded side of the discussion has a point too, because they believe there could be and probably are as yet undiscovered methods of going beyond the bounds of established science. Alchemy, if you will, formulas, new metals and shapes and chemicals as well as a plasma, maybe, and some quantum fiddling.
By the way, there is no higher court, so this is it.
Total posts : 45366I don’t want to get dragged into any controversies, but in my opinion, everything is important when you’re trying to squeeze out a usable signal from such a tiny amount of power. You need the best possible radial system and the best antenna. I personally favor the use of capacity (top) loading because it reduces the amount of inductance needed to tune the system to resonance. Less inductance means a smaller loading coil, which means lower loss (other things equal). I also think that using distributed inductance rather than base loading can yield a slight improvement. With base loading, all of the inductance is concentrated at the point where the current is highest and therefore the I2R losses will be greatest. However, distributed loading is not as easy to do, and in my opinion not as important as top loading. I highly recommend reading “Low Band DX’ing” by John Devoldere, ON4UN.
The biggest problem for most of us is probably finding enough room to install enough long radials to make an efficient ground system. You really need a pretty big yard for that.
Total posts : 45366For those interested in coil options the link below may be helpful. About 1/2 way down in the file there is a picture and discussion of a “basket weave” coil. This example was made with Litz wire but it may offer some advantage if enameled magnet wire is used. It might be worth trying.
Neil
Total posts : 45366I agree that the loading coil is the major source of loss in the 3 m antenna. In fact, the 15 ohms loss resistance mentioned by PhilB is a bit optimistic. The ground loss is also important, but it is something that can be improved by constructing a better ground shield.
I’m surprised that PhilB disparaged improving the radiation resistance from .1 ohms to .2 ohms. .2 ohms compared to .1 ohms doubles the radiated power, and this is actually better than halving the loading coil loss resistance. Center loading would improve .1 ohm radiation resistance to about .225 ohm. The center loading coil would have somewhat greater inductance than base loading, causing more loss, but there would also be less loss caused by the electric and magnetic fields from the the loading coil passing through the dirt at the base of the antenna. Center loading should roughly double the radiated power compared to base loading, and I doubt that that there would be any regulatory problems.
Like the poor man who needs to save his pennies, we need to do what can be done to get as much radiation efficiency from a Part 15 AM antenna as possible.
In another thread, Neil, ??8Z, recently talked about roughly doubling the efficiency of his Ramsey AM25 transmitter. Here is yet another 3 dB of improvement in radiated power that can be obtained legally. We should try to get such improvements wherever we can find them.
Total posts : 45366Howdy,
First, IIRC, PhilB is the well-respected designer and distributor of the SSTRAN AMT3000 transmitter kit, probably the most popular and well field-tested unit, next to the ready-built Hamilton Rangemaster AM1000.
I’ve only been on the forum for about 1.5 years, but I’ve been active. One detail I haven’t missed is that there are two rather distinct approaches to the Part 15 hobby (even if it’s a business):
1) Radio programming and community services, albeit only a neighborhood, trailer park, marina, or apartment complex. Experiments in electronics is secondary. However, ignoring knowledge in that area could lead to danger and debacle, as it did with KENC.
2) Electronic theory, experimentation, and testing, albeit it within the individual time frames available to the experimenter to learn and try new things, where some here don’t talk about programming, per se.
IMO, neither should be abandoned in favor of the other. The way I read RFB’s comments to PhilB’s message looks for all the world more like flame than criticism. I don’t believe insinuation and name-calling will help anything in this forum … save it for broadcasts where controversy actually gets listeners.
OTOH, if you take Phil’s comments, they also look faulted. I think he was referring to helping people get on the air with a good signal without spending so much time reading about and experimenting with systems that may not gain anything towards that goal. However it doesn’t include the many here who actually enjoy experimenting and exploring as part and parcel of the hobby, even if the ideas don’t work.
I’m sure we’re all aware there is NO HOLY GRAIL, only the desire to try new things, but that there are individual (and movable) ends of time and circumstance. We’re all frail and flawed, but also creative and adaptive. At any given time we all fall somewhere on the line between limitations and possibilities. I, for one, am always learning to balance (or maybe juggle ;))
Like many, I do both, and then some. FHTR is on the air 24/7 (although half of it is just NOAA Weather overnight), but I have two antenna experiments, several splitter circuits, a couple DMM-as-FSM circuits, and some other stuff on my bench, right alongside some very rare vinyl albums I need to digitize (scratch and noise removal), finish updating a couple custom software programs I wrote, and several proposals for live programming.
And now, I’m suddenly very interested in CC applications.
Anyway, that’s all just from my vantage point at this time.
Total posts : 45366Attention to the earth, the air and the domains of magnetics and electronics makes us all very much part of nature itself, and right now nature has taken some terrifying upheavals with seismic activity continuing as spring greets a large solar flare and nearby moon.
I mention all this because I wonder if it plays a role in our own moments of touchy temperament while we chat back and forth.
Hold tight and count the life buoys.
Total posts : 45366I aired Carl’s latest interview with RFB … lots of good knowledge there, BTW … if you haven’t heard it, take a listen.
One of the things talked about was the AUDIO frequency that is supposed to, umm, do something (soothing or … ?) to creatures. Don’t remember what it was, but the idea that nature affects our temperament seems highly likely. Maybe not psycho-babel, but it certainly shows us one sure thing … WE ARE NOT IN CONTROL.
That loss of life and property, feeling of helplessness to prevent it from happening, will surely put at least some of us on edge.
The tsunami could have come here, where I live. I might not be typing right now, and my station would probably be off the air (at least the AM portion). They were predicting up to 18 inches … doesn’t seem like much, but it could have ripped parts of the dock apart. It traveled to our coast in about 10 hours … means it was moving at 500-600 mph!
Total posts : 45366“but there would also be less loss caused by the electric and magnetic fields from the the loading coil passing through the dirt at the base of the antenna.”
Why would electromagnetic fields be passing through dirt?
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