I have seen something similar to this on some motorcycle sites. Sometimes it is interesting!
Today I finished building a coil similar to the plans on the SSTRAN site. I prepped it for install, only to find my antenna analyzer wouldn't go down low enough in frequency. Now I am scrounging thru my hf swr meters to see if any of my stuff will read that low power and frequency. Needless to say, I don't usually do qrp!
I did install it and "roughed it in", with the TH 5, If nothing else, it looks cool, and it may be a little more efficient. But, not being able to verify swr, I am not sure.
Decided to add a note: The TH is mounted in the toolbox on the roof at my warehouse. It was using the internal tuner with the 102 in. whip. When I added the coil, I flipped the switch to external and installed a short piece of coax from the F connector. I am in theory, in compliance for length of antenna and ground (supplied thru the coax shield to the toolbox).
Happy 4th of July to all!
Craig
us it to peak the relative field strength. i use mine with a belar loop antenna to get absolute best peak f/s from any antenna design i may use on medium wave.
if you don't have one a loop can be made and a cheap spec-an can be had from china via ebay for about $400.00 which is suitable for our part 15 purposes.
I have been considering getting a spec analyzer for several years. My wife endures my hobbies and expenditures, be it motorcycles, radio stuff or whatever...
Speaking of expenditures and still related, I just bought an assembled sstran AMT 3000 off ebay. I will be making another trip on the roof in a few days to install and compare to the range of the TH 5.
I want a AMT 5000, but maybe next month when I get bored with the AMT 3000, and realize I gained no distance or anything over the TH 5. (I hope I am wrong)
My TH units always outdid my SSTran in coverage. Audio quality is a whole 'nother story, that SSTran was one of the best sounding transmitters I've ever heard.
Lately I've been tweaking the Optimod 9000A output to get as close to 125+% as possible. I have to tune by ear which kind of drags out the process.
As I was reading thru the many comparisons and comments about SSTRAN, I noticed that the TH seemed to out perform it in distance covered more times than not, and yet the SSTRAN sounded better.
I figure I will duplicate that same scenario here. But, the improved audio will make it worth while until I decide to move to the next transmitter.
I will have to admit, this micro power AM has brought about some propagation scenarios I hadn't forseen.
"I will have to admit, this micro power AM has brought about some propagation scenarios I hadn't forseen."
Man isn't that the truth. At such low power levels our LPAM signals even seem to take on some line-of-sight VHF characteristics in addition to the usual MW propagation. I have noticed the more traditional setup you have the less weird the LPAM signal gets.
Stands to reason that at "our" power levels AM can take a line of sight transmission....because you don't have enough power to go beyond line of sight or have any ionosphere bounce.
Mark
The antenna for my AM station is installed next to a wooded area and because of the huge amount of rain we have had this spring and summer the bushes have grown to where the branches were in contact with the radiator. I spent some time trimming them back and the field strength measurably improved.
Neil
I made a comment earlier about the idiosyncracies of micropower transmissions in the AM broadcast or medium wave band. We do not have enough power to "bounce" signals off the ionosphere, and daytime signals for Medium Wave would be limited to ground wave anyway. Yet, we gain distance (or at least I do) in daylight hours. Much, as it was mentioned earlier, like "VHF line of sight" characteristics.
I have a mental image of my flea powered station not having enough power to fully develop the full wavelength and it kind of droops as it starts up the peak of the wavelength. Thus it acts less like it should, or does it? Most people blame poor night time reception of their LOCAL AM station on power reductions etc for night time service (true in many cases). But, heated daytime conditions allow the medium wave frequencies to travel faster/better for groundwave propagation, so I guess all is normal???? This is an area, that some of you experienced AM Broadcasters might expand on.
What have I done to my station today? Corrected some station id entries in RadioDJ, which I am still learning, but starting to like a lot. It is running on one old laptop, and ZaraRadio is running on an even older laptop as standby, or when I am experimenting with transitions I change the programming source to ZaraRadio.
The waves are still fully formed. The low-power just makes any noise at all extremely noticable. During the day there is less noise on MW (excluding electric grid noise), at night the noise floor raises substantially then slowly falls as the electric grid is used less and less overnight.
Heres a fun oddity I noticed today, my daytime coverage is fantastic and extremely strong in town. That being said, the signal STILL ducked on me when I drove past a utility trailer parked about 30-50 feet from the transmitter. Also fun note, the signal only ducks under a few power lines not all of them. In fact, in the next town over the lines enhance the signal. Gotta love AM!
It is interesting to see the way the signal conforms and moves with the terrain and its obstacles. I have observed the same thing here.
BTW, I am amazed at your coverage area. I am doing good to get 2 blocks here consistently and I lose that at night. We are not as flat as you are there in your part of the state, but I definately need to work on things a bit more here to get some decent coverage.
Make sure your station is "fuctionally compliant." And no damped waves.
My radio wave roller coaster has lumps in it. Or maybe they are melting in the heat.
And to think, there are comedians out of work.
Waiting on the Sstran Amt3000 to show up. At which time, I will do a short term test to verify what I already suspect. Then I will initiate a move to my residence and set up the antenna in the back yard, in a more conventional installation.
My metal roof installation, though appealing, and convenient, has disappointed me. If I were to bend the rules with additional grounding etc, it probably would exceed my expectations. But, I am trying to play by the rules, and I also am enjoying the challenge of getting the most out of this with the parameters we are given.
Setting up at home will bring about new challenges, such as being able to listen at work, since I have my doubts about reception in my building 3/4 mile away. I also do most of my programming changes during the day, so that will become a remote thing. Perhaps I will stream my audio back to work.
Damped those waves...
Before I had the power levels dialed in correctly I could pickup my part 15 AM in front of the full power's studio 5 1/2 miles away, albeit a weak signal. The same setup running at max power transmitted over 10 miles. Currently at 100 mW the transmitter goes 3-6 miles of which only the first mile is very strong, the remainder is fading gravy although comfortable in car listening lasts for awhile.