HFU HF Underground
Technical Topics => Part 15 AM and FM Station Operation => Topic started by: ChrisSmolinski on April 02, 2020, 1223 UTC
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Got a legal Part 15 AM or FM station? Interested in starting one? Post here!
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Got one on 89.5 covering my neighborhood + some
Ramsey transmitter, indoor dipole, driving the transmitter with a PC running RadioDJ into a Orban 1101e. I have a separate one on 1680 kHz as well, but seriously only covers the house and backyard.
Low bitrate pre-processor stream http://s2.free-shoutcast.com:18594/listen.pls?sid=1 (http://s2.free-shoutcast.com:18594/listen.pls?sid=1) from the FM station.
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I'm tempted to set up a microwatt power shortwave Part 15 station as an easter egg for users of my KiwiSDR. :)
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I have an EDM-TX-LCD (FM) that transmits usually when I mow the lawn and maybe a few other times. It covers the yard nicely but not too much outside of that.
Also have a Ramsey for MW, but its not working quite right and haven't been motivated enough to dig into it.
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Paul McCartney - "I'm Partial To Your Abracadabra" Probably won't hear that anywhere else... :-)
Seatrain - "Song Of Job" Probably won't hear that anywhere else ;-)
Reality is you probably won't hear much of this programming anywhere else. After 15 years of programming to people, this is stuff I like.
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Paul McCartney - "I'm Partial To Your Abracadabra" Probably won't hear that anywhere else... :-)
Seatrain - "Song Of Job" Probably won't hear that anywhere else ;-)
Looks like DJ Dickweed's been programing a few shows.
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I have a Rangemaster transmitter, fed by a Schlockwood 200 LPAM processor. Automation software is the free version of Zara Radio on a laptop, running through a Mackie mixer, so that I can do live programming. Occasionally when my best friend comes over, we go live on the air for fun. Mics are an EV RE27 N/D and Shure SM7 on boom arms.
I worked on the programming for several months, on a full-time basis. Zara Radio allows you to mark the exact segue point on each individual song file, if you're that detail-oriented (I am!) I download monthly 60 second featurettes from the US Census Bureau, and the Mayo Clinic (their Radio Health Minutes), which air regularly. I also scripted and recorded an "On This Day In History" feature for every day of the year. Free PSA's are available from several online outlets, and I air those also. The automation software airs the correct features for each day. While not a huge playlist, at 2427 songs, it's bigger than virtually all commercial stations. I also produced and voiced a bunch of ID's and jingles for the station, which is called "Ant Radio" in tribute to my best friend Ant (full name Antoinette). She is also a DJ, so is pretty chuffed that I named the station after her. The top of the hour ID contains the sound of our recently deceased neighborhood cat's loud meow. Mingus was a local legend.
All in all, I'm pretty proud of the station. In true Part 15 fashion, coverage is not even, and does interesting things. In one direction, reception falls off sharply in just a block. In other directions, it goes for about 1/4 mile before becoming unlistenable. On a very good day, I can just barely make it out above the noise a mile away. At various points in between, the signal will pop out of the noise, then disappear again. I think this is about normal for a compliant Part 15 setup. Of course, once dusk arrives, coverage suffers greatly.
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All in all, I'm pretty proud of the station. In true Part 15 fashion, coverage is not even, and does interesting things. In one direction, reception falls off sharply in just a block. In other directions, it goes for about 1/4 mile before becoming unlistenable. On a very good day, I can just barely make it out above the noise a mile away. At various points in between, the signal will pop out of the noise, then disappear again. I think this is about normal for a compliant Part 15 setup. Of course, once dusk arrives, coverage suffers greatly.
Thanks for the range information, it's interesting to learn how far Part 15 operations can get out!
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I still think it's pointless, may as well turn up the stereo or even shout, you're going to be heard at a greater distance and it's free.
Good luck with your part 15.
We don't have anything like that here thank goodness and can't say I'm bothered about it
At All.
Str.
p.s. can't see me hanging around on here much longer and I'm no longer able to advertise my wares.
Best look elsewhere methinks....
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Thanks for the range information, it's interesting to learn how far Part 15 operations can get out!
Thanks Chris. Unfortunately, I'm in a relatively dense urban environment, which limits the evenness of the coverage. If I were able to locate the transmitter in an open lot, with several hundred feet of clear space around it, I think the coverage would be more even.
I still think it's pointless, may as well turn up the stereo or even shout, you're going to be heard at a greater distance and it's free.
Good luck with your part 15.
With don't have anything like that here thank goodness and can't say I'm bothered about it
At All.
Str.
My Part 15 doesn't have particularly spectacular coverage, but I get an easily listenable signal 1/4 mile away, and my stereo won't reach that far. I sure as heck can't shout that far either - at least, not without ruining my vocal chords ;D
There's a Part 15 station not far from me, in Sausalito, CA. They're called, funnily enough, Radio Sausalito ;D A few years ago, I did a write-up on the station, and went out to Sausalito to hear it. I was surprised to find that, on walking along Bridgeway, the town's main drag, the signal was absolutely consistent for a mile. It may have been further than a mile, because I didn't investigate how far it went in the other direction. It wasn't a blowtorch signal by any means - it did sound a bit thin, but it was remarkably consistent in level for a whole mile. The station uses 6 Rangemasters. I don't know whether the carriers are synchronized or not, but I'm tempted to think that they are, due to the consistency of the signal over the part of the coverage area I walked. However, the signal did get a bit more shaky on walking inside buildings. Obviously, that can be a problem!
Radio Sausalito enjoys strong support from the city, and the local Chamber of Commerce. Their format, which is strictly jazz, streams on the internet as well. Jonathan, the station owner, told me that the majority of their listeners these days are online. The streaming fees are not insubstantial, but I'm thinking that Radio Sausalito is in an enviable position. Sausalito is a small, yet wealthy town, with strong income from tourism. I'm sure they're quite proud to have their own little radio station representing their town.
I only mention the above because, in my opinion. Radio Sausalito is a good example of how to run a successful Part 15 station. Many licensed LPFM's find that, after the initial enthusiasm of opening subsides, the hard graft of keeping it going sets in. That's when the automation systems kick in ;D At least, with an LPFM, you have decent coverage over a small area. You barely get that with a Part 15. An internet stream really helps - but then, there are the fees associated with that.
Anyway, for me, it's a hobby. I enjoy hearing my little well-processed AM signal in the neighborhood. I'm not trying to change the world, thank goodness.
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Points well made and duly noted.
I really like the fact that with only 10W and particular frequencies you can get reports from 1000's of miles away, that does make the hobby somewhat more interesting!
Str.
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I'm using an Eclipse 4000 to broadcast music in a 40k sq ft building. It's a huge antique/ vintage mall, and it was the best solution I could come up with. It sounds great FM stereo frequency range from 87.5 to 108MHz.
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(https://i.imgur.com/Ix13NXm.png)
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Took the Orban offline and now trying StereoTool free for the FM and stream. Amazing. http://s2.free-shoutcast.com:18594/
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If I didn't already mention it, I run a Part 15 AM station that I call "Radio Free Connecticut".
Here's our Facebook page. Facebook Site (http://)
And here's the web site. Radio Free Connecticut (https://radiofreect.weebly.com/)
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Oh yeah??? Here's mine, https://vk.com/realfreeradio More bitching this weekend, than anything else. The local LPFM station digs it, since it permissibly covers where they don't. And, allows me to lazy-cast.
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Pinole Community Radio AM1610 on the air for 4 years 24/7 with Jazz, Blues, Vintage Country, Bluegrass, & Oldies. And of course all the important stuff that entails the city of Pinole, Ca. Our distance is pretty good. 1 1/2 miles with a Procaster.
https://www.facebook.com/pinolecommunityradio/
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What is "pretty good" distance?
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Pinole Community Radio AM1610 on the air for 4 years 24/7 with Jazz, Blues, Vintage Country, Bluegrass, & Oldies. And of course all the important stuff that entails the city of Pinole, Ca. Our distance is pretty good with a Procaster.
https://www.facebook.com/pinolecommunityradio/
I can testify that Pinole Community Radio has quite respectable coverage for a Part 15, and also sounds good. I drove through part of Pinole once, about a year ago, and was pleasantly surprised to be able to receive a listenable signal for the best part of a mile. The audio quality was good, the music mix very listenable, and distinctly different from everything else on the dial - either AM or FM.
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Pinole Community Radio AM1610 on the air for 4 years 24/7 with Jazz, Blues, Vintage Country, Bluegrass, & Oldies. And of course all the important stuff that entails the city of Pinole, Ca. Our distance is pretty good. 1 1/2 miles with a Procaster.
https://www.facebook.com/pinolecommunityradio/ (https://www.facebook.com/pinolecommunityradio/)
How do you have the Procaster set up? Just curious about grounding, etc.
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https://www.youtube.com/watch?v=Y55dLckEvtA (https://www.youtube.com/watch?v=Y55dLckEvtA)
An FM Processing Video
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Processing is of paramount importance if the goal is to be equivalent to even classical music public or college stations in dial presence. While FM broadcast is fully capable of transmitting clean 30-15kHz "non-processed" stereo audio even when most listeners won't be listening on equipment capable of reproducing this range, Part 15 stations will be hard pressed to deliver a strong, quiet signal. High SNR makes it possible to transmit unprocessed audio with effectiveness. Hard to achieve over any considerable distance with a Part 15 transmitter. Great for around the yard. Problem is, if I'm listening on the Eton Mini, I have to turn it all the way up to hear all the music. With processing, it becomes a nice background mask to crickets, cars and airplanes.
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Chanito, I've run across that issue myself on my lil' part 15 AM transmitter board, it doesn't sound as loud as other stations, unless I blast it hard into distortion. The sound is very good though I just don't think anyone will be able to hear it well and noise creeps in.
I've tried a software compressor and it works well and know about band rack compressors but I'm thinking there should be a small box that I could plug a phone into and that into the channel combiner to the transmitter, like the ALC level controls in a tape recorder would have. Not the sound pro stations have that sounds like tape being far overdriven, just something that keeps an even keel on the sound.
I was reading on a part 15 radio board that the high compression level of pro stations shouldn't be used. Once you hit a certain level, where the sound is processed, any more and the sound just loses definition and the distortion increases. I like how clear and defined the old AM stations used to be, you could hear every word in the songs!
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One passing contemplation here, (Not thought, as that would hurt too much.), would be to see if your AM TX is possible of even going 100% modulation. There's some cheap kits out there that struggle to do 50%, at best. Anyway to put that to an o'scope, or an off-air AM monitor VU meter, to see what a 1kHz test tone does when you vary the audio input level? Then again, just like most modern day CB's, there maybe a limiter in your TX to on purposely keep that level low, in order to boast Part #15 FCC compliance. (OK, that was a couple of contemplations.)
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My transmitter probably doesn't have full modulation, and the antenna's tuning changes the audio quality too. I have heard that some transmitters have limiters in them, to keep you in your lane, audiowise. Can the circuit in a home transmitter even get as loud as the pro's?
One thing I did was use my audio editor to make shows and use the Compression and Hard Limit on a music set or program. First run it through compression to make the sound tighter, with a second pass with hard limit for a few more DB of loudness. Done right it's hard to tell it's compressed when listening, but it's louder on the air.
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Of the Part 15 AM transmitters I've used, the Procaster and Rangemaster can take as much modulation as the processing is able to provide, up to +125% or more (100% negative.) These can be as loud as the 'pros.' The TH 5.0 I have as a backup has an internal compressor of sorts, which apparently isn't defeatable, so in that case you get what you get.
I'm now using a Schlockwood SW-200 3 band processor with my Procaster, where it's really helped the fringe area. More is better here: AM peak envelope power (PEP) is 4x carrier power at 100% modulation, and cranking up the positive modulation with a suitable processor can increase PEP even more. You get more power on the air...legally.
I do recommend the Schlockwood, which can be both loud and pleasant sounding.
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I do recommend the Schlockwood, which can be both loud and pleasant sounding.
+1 for the SW200. I've been using one with my Rangemaster continuously for over 2 years now, and it has performed flawlessly. Although the front panel controls might seem a little daunting to someone who hasn't used this type of broadcast processor before, it's pretty hard to get a bad sound from this unit - as long as you don't overmodulate the transmitter, of course.
I only had one concern when the SW200 was coming onto the market. Although, IMO, it's a good deal for genuine multi-band broadcast processing, Part 15 hobbyists tend to be budget limited. I was happy the initial production run sold out, and that sales were enough to justify a second run. I do hope the SW200 will remain on the market for quite a while. However, I am never going to give up mine, as I feel it's a classic. Same goes for my Rangemaster, and even my Behringer Eurocom SPL3220 which, for ~$100, delivers a very listenable sound. Other pieces of gear may come and go, but these ones will stay with me. If I sold them, I'd just end up trying to get them back at some point - and there are very few SW200's on the used market, as there are not that many in existence to begin with.
Great piece of kit. Buy one, and hang onto it!