We hear it everyday the bigger the antenna for AM the better. But I had a phenomena I need to explain to you as I was experimenting. I first used the supplied wire of around 8 Ft that comes with the talking house 5 as I just could not get any real range and the Audio quality was Pure T you know what.
The highest meter reading in DC volts with my home made ATU was only 3 ½ maybe 4 volts if I really sat and tried to tune it over and over. Pretty crappy from this transmitter. I got an idea in my head to try something unheard of. Since my home brew ATU has a screw terminal I took my wire made for FM from my Whole House 3.0 transmitter and decided to try this wire and see just what I'd get from the meter. I got that bugger up to almost 8 volts DC. This means that my shorter wire was far more resonate than the 8 ft piece of wire that came with the Talking House 5.0.
The audio quality did seem to improve just a bit too as I have the window blinds holding the wire. The blinds have very thin metal pieces that make up the window blinds.
So did I stumble on the fact that with the Talking House AM Transmitter that thinner wire is better? And maybe because of the minute power levels we're using it is unlikely this transmitter can feed the power all the way to an 8 Ft piece of aluminum wire.
There is a question of ohms too but I'm sitting here with 8 volts going right to the antenna where as before I could not get that much out of the Transmitter.
Now the real test would be a drive test and a walk around test which I'll have to perform on this thing with this wire as I think I'm on to something here.
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Boards of Canada.
Thay guy in the antenna demo video has a lot of good things going for him, I don't know what his ground conductivity is, but his area is pretty undeveloped where he was driving, so it's quiet and it's flat. I think the best thing he has going for him could be the clear area around his antenna, and the ground system's decent too.
Mr. Rich took a wrong turn in Post # 23, reproduced here:
Clip from Reply 22 of this thread (author = C. Blare):
... "Whenever we talk about loading coils for medium wave antennas I like to share this tid-bit from KGLFH printed on page 19.16 0f the Radio Handbook..."
Would you mind linking to even _one_ of your posts prior to Reply 22 here to support your allegation pasted above in this post?
BTW, the original source was K6LFH, not "KGLFH" as you stated.
Then you posted in Reply 22:
"... A loading coil mounted at right angles to the whip has been found to greatly improve the Q, as contrasted to the usual arrangement where the coil is in-line with the whip. ..."
Those conclusions were based on undocumented statements for mobile/portable antenna systems using capacity-hat top loading in the 80 & 40 meter ham bands, which configurations are not very likely to be acceptable to the FCC for unlicensed AM broadcast band systems/operators operating legally under Part 15.219.
Suggest that such concepts be fully researched and understood before believing/posting/implementing them as applicable to Part 15 AM systems.
1.) There is no "allegation" made nor any relevant reference to prior posts;
2.) No "conclusions" are reached by me nor the original author;
3.) A loading coil is not a capacity-top hat and is a separable topic;
4.) The fact that the antenna discussed in the reference was mobile/portable or designed for certain bands is not germaine to the discussion;
5.) The physical placement of a loading coil does not bear on legality under part 15;
6.) The concluding line: "Suggest that such concepts be fully researched and understood before believeing/posting/implementing them as applicable to Part 15 AM systems." .... a foolish statement on six levels.
Finding a metal box for the coil could get pricey. I have access to industrial electrical goodies that get demolitioned, so I come by this stuff at times. I'm looking for a suitable exterior, plastic box for my transmitter and have settled on a $20 cable tv box. A metal one doesn't come in at less than $50. And if I came across a box I'd consider mailing it to you but the postage might eat up the reality of you just buying it local. Hey! Consider going to a junk/recycling facility. They might have a box. Also, get friendly with a few contractors. They throw stuff away frequently.
I think you directed this at me. If so, thanks!!!
I am not needing a box, I am considering mounting my existing coil in my toolbox that I am using at present for my AM transmitter. I just haven't had time to test yet. I hate to mess with what I got, since it works fairly well.
I do have access to some decent sized ammo boxes that are fairly inexpensive. Anyone wanting to try this might consider that also.
Working on getting our small town of <4000 local programming.
Mr Blare, re:
So you say, but the allegation was yours: "Whenever we talk about loading coils for medium wave antennas I like to share this tid-bit from KGLFH [sic] printed on page 19.16 0f the Radio Handbook..."
I asked you to prove your allegation by posting a link to at least one previous occasion of sharing such a tidbit -- which you have not done.
It is your burden to support the accuracy of your posts, not that of the readers of your posts. And who knows better the contents of, and the links to your posts than you do (or should do)?
The accuracy of the other 5 rebuttals in your reply 34 is left for their readers to research and accept/reject.
Another of the many errors in Post # 23 when Rich claimied: "Those conclusions were based on undocumented statements."
The "statements", by which I assume you mean those of the author, were documented by the fact that he was quoted in a book and then again by the fact that I quoted the him here.
And again we remind there were no "conclusions" made by anyone.
You have reached the height of speciosity.
As to linking to the previous several times I linked the same quote just repeat the present quote three times and it would be like that.
About Reply 38 (C. Blare):
... "Those conclusions were based on undocumented statements."
The "statements", by which I assume you mean those of the author, were documented by the fact that he was quoted in a book and then again by the fact that I quoted the him here. ...
Documentation is not the natural consequence of a simple statement published in print or available on the Internet, even if you (and/or others) quote it, and believe that it is.
In this case, documentation requires scientific study producing published results/data that can be replicated by independent investigators, and which is relevant to the operation of FCC Part 15 AM stations.
So far you and your references have provided nothing of that nature.
LOL Carl Blare and Rich should get on radio together, it would make for one hell of a comedy show! HAHAHAHAHAHAAHHAHAHAHHA!
I love it!
Carry on guys!
I concur, I think that it would make for a heck of a part 15 show. How about it guys???
Solipsism in philosophy is the doctrine that an individual projects the world.
The world projected by Rich is light years from the part 15 hobby world the rest of us project.
Consider his ravings:
"Documentation is not the natural consequence of a simple statement published in print or available on the Internet, even if you (and/or others) quote it, and believe that it is.
"In this case, documentation requires scientific study producing published results/data that can be replicated by independent investigators, and which is relevant to the operation of FCC Part 15 AM stations.
"So far you and your references have provided nothing of that nature."
Those comments would fit a medical white papers website or NASA space flight project but are miles from anything being done in part 15.
I won't be providing anything "of that nature".
Part 15 in 2016 has two laundry piles...
One is the hobbybroadcaster embarrassment which we talk about because it's so over the top.
The other laundry heap is Rich trying so consistently and persistently to discredit me which is bizarre in that I take no particular credit for anything significant.
The moderators don't want brawling members soiling the threads and many threads get closed when the topics become obscured.
Perhaps Rich would consider spreading it around a little and discredit other members for a change and leave me out of it.
This thread is about loading coils and some very interesting ideas have been presented, aside from any debunking that may have attempted to shut them down.
I haven't read the article about why a horizontal coil would work differently than a vertical one, maybe it could on over the ground plane of a car, with a cap hat? From my experience, coils by themselves don't have much of a field, the ferrite receiving loops or PVC coils with a few inches of wire on them. If the coil was really long I could see an effect, because the coil itself would be another radiator, but short as it is, it doesn't have the surface area.
Even the idea behind "thread drift" is kind of illogical when you look at it, because people read different parts of an article and filter out posts they don't want to read anyway.
I like to see the shootout with Carl and Rich, it shows that all is not rules and regs, I like the conservative versus liberal viewpoints, it makes for good talk radio. This is the fun site, I'd hate to see it get like other sites, (which I haven't really read, but infer their politics and quirks). I won't bother to stay at a site that tends to the draconian, I'll have fun on the radio instead.
In response to a post about horizontally mounted coils increasing Q, I had asked if the same situation could be posturized as possible if a coil were installed IN a metal box under the antenna. That is, if the antenna were mounted to the top of the box (outside), and the transmitter coil etc were INSIDE the box. This might be or might become a typical installation for some Part15'ers. In my case, I am using a metal toolbox with both the coil and antenna mounted to the top.
I propose, without basis or fact, that the coil mounted in the box would not have the reactance with the radiator and thus:
a) IF the coil were capable of increasing Q by being placed horizontally when NOT IN the proposed metal box, would it do so WHEN IN the proposed metal box?
b) There would be reactance/coupling with the metal box and I propose antenna matching (coil taps used) would be dramatically changed from the same installation of the coil mounted outside the box.
c) Comments - Theories???
I also want to propose that in regards to mobile applications on 40M and 80M:
1) A capacitance hat, the loading coil, radiator etc actually have a "sweet" spot in relation to the distance above the physical earth on vehicle. The theory is that a "coupling" takes place that actually increases efficiency in some situations.
2) This has been discussed at various times during "antenna shootouts". This vernacular is a term related to when Ham operators get together to test antennas and different configurations of those antennas. Vehicle style and composition may effect this also.
3) The above paragraph might be applied to a 180 meter installation (AM Band), if said antenna were were mounted either on a post or near ground with radials (as was possibly demonstrated in a earlier youtube link).
4) I have no hard data on it, but I would theorize a relation to wavelength would apply thereby further increasing efficiency.
5) I further theorize that since we can not fully rely on given knowledge for a true 180 meter (AM) antenna installation because of size limitations applied to us by Part 15 rules, that very little written data exists. Most software modeling falls apart falls apart outside of the given parameters it was designed for.
The concept of coils in use with Part 15 Am broadcasters is important. It is currently the best we have to match our limited radiators to the output of our transmitters for maximum efficiency and range. Time spent on this is a good investment.
Lets continue the discussion!!!
And I still think a good discussion regarding this topic would be a great topic for an upcoming "Blare on the Air."
I have my shoulder pads on... The ball is in the air...
CraigF wrote: "I had asked if the same situation could be posturized as possible if a coil were installed IN a metal box under the antenna."
My immediate reaction was to wonder the same thing and evenb leap to a decision... deciding that coils should be mounted in metal boxes.
Also, I agree that the coil in a metal box will be changed in value caused by reactance with the metal around it.
Outdoor coils have been protected from weather by sealing them with varnish or placing them in plastic buckets, but metal seems right.
Of course we can go "All Coil" on Blare OnAir.
craigf Your last post really has me at interest, specially since I am working on bringing my Chris Cuff C-Quam AM STEREO transmitter out of the dorment period.
Chris Cuff who is a member of several facebook groups, is the one who desinged the AM C-Quam Stereo transmitters and sold the kits on ebay. He had a bunch of PC boards etched at a place that does that and has just told me he has some boards left and all the plans to build the kits. Even Bill DeFelice loves Chris Cuff's AM stereo transmitters. So what does that tell you? That Chris is a highly respected hobbiest just like us.
If new interest is gained in AM stereo, he might mass produce those kits again.
Any who, I am about to replace the generic transistor my already assembled kit had with a 2N3035 type, this will put that danged thing up to part 15 100mW, then I will be looking at building an outdoor antenna for this AM transmitter which is currently crystaled for 1250KHz, that is unless I buy another crystal to go to a higher frequency.
I am trying to get Chris Cuff to join this forum board and participate in discussions about AM stereo, he told me on Facebook, he is going to attempt putting together tube operated kits as well.
I know many say there are no AM stereo radios out there, but I got one off ebay, it's a Realistic TM-152 and it works quite well for a used item many years old.
I would like to have a forum board section set aside for primary discussion of AM stereo basics and see if Chris will participate with us on one of his interests.
Any who, I'm getting tired, time for bed, but I'm really interested in ANY discussions about AM antennas at this point and time, I think my town needs an AM stereo radio station and I'm gonna be it!!
I might add that comercial AM Antenna Tuning Units have a large inductor housed in a metal box.
Druid Hills Radio AM-1710- Dade City, FL. Unlicensed operation authorized by the Part 15 Department of the FCC and our Resident Hobby Agent.
I think it would be great if Chris joined the group. I would also like to see a quality stereo transmitter available. I would be interested in one myself to tinker with.
I am not sure how much of a market there will be for any AM transmitters. Granted there is interest, but unlike cell phones, not everyone has or needs one!
Another good piece of information! Of course, it is probably best with the power available to most commercial stations!
Engineering Radio's Paul Thurst puts coils in metal boxes.... scroll this...
BIG FAT COIL METAL BOX
Coils in boxes are apparently good things if adapted to the transmitting environment/matching etc.
That looks like the arrangement I have for my 1710 operation here in Druid Hills.
Just an update, my order from Mouser for those 2N3035 transistors just came in, time to work on my AM C-Quam stereo transmitter and finally work with an AM transmitter.
I recall reading in the 1958 ARRL handbook that antenna tuner coils and transmitter final tank coils should be shielded in a metal box, could be solid or perf, to reduce harmonic radiation.
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Member Station - ALPB
I need to find my old ARRL books. That makes sense, and on a side, yet related note, I find it amazing what those guys did in the 50's to go mobile HF!
And on another side note, yet related. A properly designed coil with a narrow bandwidth, can help reduce harmonics. A screwdriver antenna is fairly efficient at that because of its narrow bandwidth when tuned to a specific frequency. They work wonders to help kill harmonics of less than properly designed mobile amplifiers.