Credit where it's due, Neil. Some time ago, Rich said that by his calculations legal FM and AM part 15 range shouldn't be that far apart. Much debate and math followed, but you know how rare it is for Rich to actually be wrong on such a matter. That was in the back of my head when I remembered I had an FCCID unit onhand, though what we'd usually think of here as a "toy". If Rich hadn't said that, and there hadn't been the long and patient explanation of the equations with examples, I would have probably just tossed it back in the box, sure it "couldn't go more than maybe 20 ft".
However, the topics and calculations had been interesting enough that when I found the data on the FCC site for the "003", I wanted to take it out into the open and try elevation and get some actual field data (though crude) to see how close it was to those numbers that had been calculated.
So, kudos to Rich. He puts a lot of time and work into his calculations and explanations in his effort to better educate those in the hobby with an interest in the physics/math/theory that is involved.
Now, Lee's C. Crane is likely a lot closer to 250uV than the 150uV of the "003". So he's getting what appears to definitely be a bit better range than my test.
Lee, what sort of receiver were you using at 800 ft?
The C. Crane is sounding like a very interesting unit for FM part15 with a certified unit. It wouldn't cover a whole town or much of a city, but my interests are more in "very small-scale community radio", basically my own yard and nearby neighbors. It *could* cover larger areas if enough units were used, as is already being discussed.
Personally, I like "very small scale" since it's possible to know one's listeners personally and tailor content so there is at least something each of them want in the programming. Whether it's the weather being there within a few minutes of their clock radio going off in the morning, or stories in the evening to get kids to sit quietly and listen for a while before bed-time. Birthday and special events congrats or telling the kids listening in the morning if they have a snow day. Those are little things, but they are the sort of little things that I feel have gone missing in radio as it has turned more to large-scale corporate control and priorities over the years.
Daniel
So, kudos to Rich. He puts a lot of time and work into his calculations and explanations in his effort to better educate those in the hobby with an interest in the physics/math/theory that is involved.
I certainly agree. Rich is a great resource for this and other boards since he is willing to share his knowledge, and he has helped me many times.
Neil
Thanks for the good words, Daniel and Neil -- much appreciated.
Rich
I just re-read this whole thread (without prompting), and certainly I should have included my thanks to you for your support, RadioheadC. Probably I should have included others as well.
But I am just one contributor to these boards.
Implicit in these many posts (including mine) is that their validity needs to be reviewed, researched, analyzed, and accepted/rejected on their scientific merit, after due consideration by their readers.
//
The range was tested on my 98 Monte Carlo's factory bose system,good to 800 feet in the clear and about 450 thru the rows of houses into the next block. A quick test with a bicycle and a boom box gets about 30% less range with more drop-outs probably due to multi-path. It is also side mounted on the tower and gets only 150 feet off the back side,the tower may be adding gain to the front side signal. A true test would be if it was in the clear but I dont have that option right now. Gonna work on that one....
Regards,Lee
http://www.freewebs.com/wilcomlabs/index.htm
Hello
I saw your little website and setup. Looks really professional. I am thinking of buying the EDM FM transmitter. Is it worth it? What version do you have 10mw or 100mw? How much range does your EDM give you?
WHO's website? The EDM-10 is NOT a certified unit and puts out more than the legal limit of power,the EDM-100 is WAY too much power! The EDM also suffers in audio quality and pilot crashing.Thats why I bought the C.Crane unit. It IS certified and has no audio or pilot issues and will keep you legal if you dont modify it. My advice is to read through these forum posts,there is a lot of good info here by very knowledgeable folks who have taken the time to share their experiences with us. You must draw your own conclusions and do what you feel is right. The emphasis here is to promote the running of a LEGAL part 15 station,to promote experimentation and development of ways to get the most out of our hobby,and to have fun with it.
Regards,Lee
http://www.freewebs.com/wilcomlabs/index.htm