So- after MONTHS of messing around with 'you know who' at FRB, I finally bought a 15 watt Chinese transmitter on eBay. I also picked up a good 1/4 wave because the one included with the transmitter was pretty cheap. I've got it on a chimney about 90' off the ground. So far the transmitter has worked flawlessly. I have a professional studio with an RE 20 microphone, Gemini DJ mixer, EQ, compressor/Limiter, turntable, two DVD players, a CD changer and a laptop. I have a perfect signal for a couple of miles in each direction, and can pick up a decent signal in my truck up to 10 miles away. I spent a lot of time researching the frequencies for 100 miles and settled on one with 2 meg on one side and 4 meg on the other. There is another station on the same frequency but it's a 100 watt LPFM in Washington county. When I get out in the suburbs it sometimes wipes my signal. I have two concerns- One is that the station is an Ultra-conservative Christian station. It might be possible for some fanatical listener to get on my case. However, I've been on the air about two months now and everything seems cool. My other concern is that my signal might be TOO good. I could probably get the signal coverage I need with the antenna in the attic, which is not a bad idea. I still have my Ramsey FM25B set up and ready to go if someone comes snooping around. I've told my neighbors the antenna is for a shortwave receiver. I have some cards I'm handing out and I've created a couple of "Drops" at local businesses. So far I only have a few friends listening, but they are devoted. If I sign off early, I get complaints. I broadcast uninterrupted music all day and I've just extended my hours. When my listener base gets larger I plan to add some more creative programing, like original humor and old radio shows. My signal covers the University of Louisville and if I get noticed there it would be great. Anyway, I just thought I'd share. Wish me luck. T.
im running a hlly 30 watt with a home made copper pipe jpole. im in florida so its all flat here. i get about 5 miles through dense urban jungle. i know i have listeners as we've heard people in their cars with the station on.
as long as you keep it clean the bible thumpers wont notice you.
Congrats on the success, and I like your audio setup.
Man, wish I was able to put up an antenna 90ft!
but... do you really want to have that much coverage? It's great to have a lot of range, but it comes at the cost of crushing some "front ends" on radios within a couple blocks of you. I hope they don't have their front ends desensitized and unable to listen to their favorite station on either side of your TX freq. That's always a concern in an urban area. Perhaps you can get in your car and run some tests a city block or two away, listening on adjacent channels.
IMHO, I'd consider lowering the power and keeping the antenna at it's present hight.
Yeah, too much power is something I've thought about. I only want to cover my neighborhood, a couple of square miles. I've tested swamping and harmonics in my truck right outside on the street. The band filter seems pretty good. I've also checked with my neighbors and they haven't noticed anything. The transmitter doesn't have a convenient power adjustment, in fact the RF section is sealed. I think the best idea is to put the antenna in the attic. That would, of course, kill two birds with one stone. It would lower the effective radiated power, and it's hard to zero in on an antenna that you can't see. As far as being on the air, I keep it professional, and simple- no ads and of course NO profanity. Also no rants and raves about controversial subjects. I do a station ID about every hour and sometimes promos. That's it. I don't even use an on- air name. Right now it's kind of automatic, mostly misc. music DVDs. Two of those last all day. Sometimes I load up the CD changer. Today I'm having "Artist Appreciation Day". I load two or three CDs of someone like Bob Dylan or Johnny Cash, and let 'em play. Pretty cool, huh?
Yea, an antenna that is totally out of sight makes "detection" more difficult... and that's a "plus".
On the downside, that usually means that the rf field present at the location of the transmitter, and audio systems feeding it, is stronger. Of course, that means there is the potential for rf getting into the gear, especially since you can't crank that 15 watt level down easily.
Would the transmitter operate on , let's say 12v instead of 13.8v?
That would certainly lower power somewhat. Of course, you would have to make sure the lower voltage caused no problems with the transmitter by looking at the output on a service monitor.
Or, how about constructing a 6db 50 ohm attenuator at the output of the transmitter? That would only require a few resistors, and would reduce the output to 3 or 4 watts.
With an indoor antenna and 3-4 watts, that would be sufficient to cover the couple miles you wanted easily.
You know, I've had so many problems and disappointments, not to mention time and money invested in this, that I'm afraid to mess with it. I agree with all of the ideas, but right now it works. This has been MONTHS of frustration- first I bought the 10 watt kit from FRB and that didn't work. Of course the instructions looked like some stoner made them up. Then I bought a HILLY 5 watt. It overheated. Next was the assembled FRB 10 watt transmitter. IT didn't work. Remember I have another person testing these. With the refund from the 10 watt, I bought the one I have now. When I first turned it on me and my dog walked around the neighborhood listening with a Radio Shack headphone radio. Every time I shouted, "It works!", he looked at me like I was crazy. Of course my main concern was getting out at all. That's why the new antenna went up on the roof. It wasn't until I bought a truck the other day that I was able to really drive out to the fringe areas. That's when I started realizing how much power I have. The more I think about it though the more I want to leave it alone for now. I have a great stereo signal covering the area I want, and right now that's good enough for me. Remember that I'm in the widest spot on the dial. That should help keep a low profile, and very few people have 'tunable' receivers anymore. Someone with a digital receiver would pretty much have to know where I am. I guess a 'seek' or 'scan' function would find me, but that could be a good thing. Remember I just broadcast uninterrupted music all day. In today's terrible radio market, I'm an oasis. And that's a good thing!