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- July 27, 2004 at 5:55 pm #6221
Need Part 15 info for Broadcasting Music
What is the best part 15 frequency other than part 15 am to broadcast music on. How many watt is it and how high can the antenna be.
July 27, 2004 at 7:26 pm #11765mlr
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Total posts : 45366it’s all opinions ๐
FM is the next best – but you can legally broadcast around your yard with it.
Some folks are claiming a half mile or so – but I’ve not seen that personally.The antenna for FM is not the limit – it’s the FS – take a look in the library on this website and you’ll find lots of info there.
If you want to bcast regular shows – your best bet is to use AM or the internet..
July 27, 2004 at 11:06 pm #11766scwis
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Total posts : 45366I believe that for unprocessed sound, bandwidth is going to be the key to nice sounding music.
If that’s correct, mlr is right that wide band FM in the FM broadcast band will sound the nicest. The problem there is that it’s the most limited in range and the most scrutinized by the Friendly Candy Company, from what I’ve read around the web.
There is one rather cumbersome way to get more distance for your FM, if you’ve got the means. There is an approach called leaky cable, where you transmit through a cable that runs through your broadcast area instead of an antenna. The cable has little slits in the shield that allow a bit of RF to ‘leak’ out, and your rule there is that the field strength limits for FM are applied to the cable, rather than your xmtr. That means you can put out a signal a few hundred feet on each side of the cable, for as long as the cable runs. Some drive movies did that, and other applications have been used, as well. If you have access to poles or ground (you can even bury it an inch or two below the ground to protect the cable) you can do that.
Narrow band FM on the “baby monitor” band – 49 MHz, would probably sound second best, because even though it’s NB it’s still FM – no natural static, etc. The problem there is that there aren’t too many receivers, so few could listen.
The Hifer – 13.55 MHz, is a shortwave AM band. Pretty good range, a few more receivers, but it’s very narrow bandwidth, and has lots of snap crakle and pop.
Low band AM euro style, 230 – 535 KHz has a much wider bandwidth, but has the interference problem, and who can tune in those freq’s here in the USA?
Then there’s lowfer 1750 meters – 160 to 190 KHz God knows what you could do with that ๐
That leaves good old AM BCB, and maybe some digital or analog compression and other processing to get the better sound.
My 2 cents ๐
July 28, 2004 at 1:12 pm #11767frankh19
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Total posts : 45366With today’s radios, FM sounds the best. Manufacturers put most of their efforts into the FM receiver, with AM being an afterthought. But, license-free operation limits your transmission distance severely.
You do have to be very careful on FM because both the licensed broadcasters and the FCC are on the lookout for illegal operations. There’s a thread on the Ramsey Electronics forum about a guy who’s running a legal Part-15 FM, and a licensed operation 35 miles away has threatened to report him unless he shuts down.
Given today’s climate, if you can run AM, do it. You’ll sleep at night.
August 1, 2004 at 1:43 am #11768DJboutit
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Total posts : 45366So which part 15 would give me the overall best sound & range I am just getting in part 15. Where can I get info on the part 15 setup so I might build it or buy a ready built setup. ๐
August 1, 2004 at 1:57 am #11769frankh19
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Total posts : 45366It’s a trade-off. For the best sound quality, it’s FM. But your coverage is limited. For the best coverage, it’s AM.
The way the rules are written, on FM you just don’t have the legal coverage that you do on AM. And, FM is ‘the money band’. That’s where all the popular, and thus, highest billing stations are. Broadcasters are going to protect their investment and wouldn’t think twice about turning someone in. It’s happened in my area.
So, having said all that, you should strongly think about putting up an AM. Yes, it’s more work. You won’t be able to buy a Ramsey off Ebay and get on the air. But, you’ll learn a lot and have fun at the same time.
August 1, 2004 at 2:28 pm #11770part15er
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Total posts : 45366Get a transmitter with built in audio processing (if you don’t already have audio processing stuff) like one of these:
[url]http://www.vcomp.co.uk/gizmo/metzo/metzo.htm[/url]
[url]http://www.sstran.com/[/url]Build a base loaded antenna for range, like one of these:
[url]http://www.part15.us/modules.php?name=Content&pa=showpage&pid=9[/url]
[url]http://www.part15.us/modules.php?name=Content&pa=showpage&pid=11[/url]
Have fun ๐
August 2, 2004 at 1:49 pm #11771DJboutit
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Total posts : 45366I am thinking about going either lowfer 1750 meters 49mhz Hifer – 13.55 MHz what do you guys think about that. If you had to pick out of those which one would you chose. Thanks for all the help guys.
August 2, 2004 at 5:16 pm #11772frankh19
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Total posts : 45366Given those choices, go 13,550. You will have a chance at greater listenership.
August 2, 2004 at 5:27 pm #11773DJboutit
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Total posts : 45366Need info on a transmitter and a antenna where can I buy them and what would you reccommond I should get.
August 2, 2004 at 6:04 pm #11774scwis
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Total posts : 45366I agree with frank19, 13.55 MHz will give you distance and greatest chance of having listeners – at least SOME people still have short wave.
From [url]http://home.att.net/~weatheradio/part15.htm[/url]
“HF Part 15 stations occupy a narrow slice of the 22 meter shortwave band… In practice this works out to 1.8 mW transmitter output power into a 1/2 wave dipole, or 3 mW into an isotropic (0 dBi) radiator. …On this HF band, unlike Part 15 mediumwave, there is no limitation on the size or type of antenna, feedline or ground nor on power output of the transmitter, except with respect to whichever combination of antenna and power chosen is required to reach the legal limit of field strength (of 10,000 uv/m, compared to 250uv/m on FM {scwis}) without exceeding it.”
From the same page, a transmitter is here:
[url]http://home.att.net/~weatheradio/HFtransmit.htm[/url]
August 2, 2004 at 6:18 pm #11775mlr
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Total posts : 45366wait.. you can run a real radio station on shortwave…under part 15? what kind of range are you expected to get? ๐
Can we start a new thread on this?
August 4, 2004 at 12:41 pm #11776tregonsee
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Total posts : 45366Here goes nothin’.
1. LowFER (160-190 kHz)
Pros: Highest power input, most metal in the air, least critical construction (lead lengths and PC board trace lengths get more significant compared to wavelength as frequency rises, and must get shorter)
Cons: Little if any prebuilt or kit transmitters or receivers, atmospheric noise, perhaps interference
2. MedFER (510-1705 kHz)
Pros: Lots of AM receivers (some good), fair amount of prebuilt and kit transmitters, good balance between available equipment, power, and metal in the air
Cons: More high-power stations moving into extended band, other noise and interference
3. HiFER (13,560 kHz)
Pros: Full-size quarter-wave or half-wave antennas are workable, often less noise and interference than MedFER, fair number of SW receivers around
Cons: Have to calculate what the signal strength of a particular xmtr (transmitter) and antenna setup should be (15,848 uV/m is about 4.9 mW into a half-wave dipole or 1/4-wave vertical over ideal ground), no pre-built or kit xmtrs that I know of, room for only one HiFER AM station in a given area (ROUGH guess 5 mile radius, but this may be lowball)
NOTE: The home.att.net site has the old 10K uV/m strength limit
4. 49er (49.82-49.90 MHz)
Pros: Waves behave more like FM (line of sight or LOS) but still something like SW at times, should be less noise, scanners should be able to pick up FM xmtrs
Cons: Shared with baby monitors and other junk, no pre-built xmtrs that I know of, alternate standards are only 100 mW TOTAL power input to ENTIRE xmtr (not just final RF amp like MedFER) and 1 meter single-element antenna mounted to xmtr case
Thinking LowFER/HiFER/49er? Dig out that electronics book and soldering iron. You’ll probably need it.
Advice to all: uV/m is microvolts/meter (peanut whistles – us); mV/m is millivolts/meter (rock crushers – big boys – don’t like competition)
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