Guest blog post by Cash Newmann
I’ve seen a lot of posts on FM micro-transmitter systems, but they’re all lacking in this detail or that. For instance, a lot will say “make sure you’re using a low-pass filter”, but then don’t say how, or where to set it up in your gear chain, or specifically what adapters you need. I made this post to fill a void. This post includes details of ALL parts needed, links on where to order them, and how to set them up and configure them, as well as a lot of related information based on experience.
SCHEMATIC (not to scale) THAT SHOWS HOW TO SET IT ALL UP (click to enlarge)
I’ve experimented with the transmitters below, so this is from first-hand experience. But I did it on a boat, 200 miles from shore, in international waters. I do not own any of this gear, I sold it to some church folk at a gun show after I was done testing it. And I am not currently transmitting from my house or anywhere else. I’m just passing on information, in a theoretical capacity, for educational purposes only. Nothing here is legal advice, I am not a lawyer. I take no responsibility for anything you do or anything that happens as a result of doing anything listed below. ALL OF THIS IS FOR EDUCATIONAL PURPOSES ONLY. DO NOT DO ANYTHING SHOWN HERE.
Firs question: WE HAVE THE INTERNET. WHO NEEDS RADIO?
Podcasting is cool, but radio can reach people who would never find a given podcast…those who are not Internet savvy, or even people who are who would just never find a particular podcast otherwise. People often channel-flip while driving (especially when stuck in traffic) and inexpensive low-power community radio can reach those folks, bringing them a voice of true liberty.
Besides, radio is fun. There’s a thrill you get from being in your car listening to something you put out without the nerding around of the Internet. Radio is low-tech and almost like magic. Other people who listen to your show will grok that thrill too.
Time was when non-profit groups in America could get a license for a community radio station of up to 100 watts, which can more than cover a large city or even a county. But a while back, the gub’mint sold out to a very small number of huge corporations who each own most of the radio and TV stations in every town. These government-backed monopolistic conglomerates fired all the DJs, replaced them with computer-automated DJ bots with songs picked by business dorks. When there are real (nationwide) hosts, many of the people calling in are coached, paid actors pretending to be real people. The conglomerates kicked out the free thinkers, and riddled the shows with cheesy & ads, and “news” that only exists to drive horizontal enforcement of statism. That’s why every station in every town sounds the same, plays the same horrible music, and sounds like they choose what to play based on math and marketing and keeping people sheepish, rather than taking chances and making decisions based on taste.
In the USA, you can legally transmit on an open frequency if it’s basically not strong enough to reach past your yard and maybe your next-door neighbor’s yard (what Dale Gribble on “King of the Hill” called “the most powerful station in the tri-yard area.”) This is called Part 15 Broadcast. That name is based on the part of the document with all the damn rules. (They are rules, not laws. Laws can only be passed by Congress. These are rules written by bureaucrats who try to enforce them as if they’re laws.)
While the Part 15 limit is based on a number of factors, including transmitter output wattage, antenna size, antenna type and antenna height, basically if you’re broadcasting at 100 mW (1/10th of a watt), you’re within the spirit of the rules, which will usually keep you from getting hassled.
While using a radio transmitter on an unused frequency for community radio is a CLEAR natural right, as well as use of the First Amendment of The Constitution of the United States (that the United States is supposed to abide by), the pen-pusher fed goons don’t like it. They make part of their living selling permission slips to transmit, and they rake in billions from this.
Also, there is a long tradition of transmitting freedom propaganda into occupied territory, such as the USA’s ongoing Radio Free Europe, which violated Soviet law to transmit into the USSR and into East Berlin during the Cold War. They still do this all over the world, while at the same time, preventing us from doing the same here, AND trying to regulate what we say and do on the Internet. The USA is now occupied territory….the Occupied States of America, with a cop on every corner, and no respect for Natural Rights or the Constitution. If the Occupied States of America thinks it’s their right, shouldn’t it be your right too?
While many citizens do run transmitters at 500 mW (or even much higher) for YEARS without getting in trouble, breaking the law is bad, um’kay? I’m not recommending you break any laws, even nanny laws! We have a social contract. Abide by it or society will degenerate into anarchy!
Many countries do not have the same draconian radio laws as the US (“land of the free”, my ass), so I’m gonna tell how they do it in other countries. DO NOT RUN A TRANSMITTER ABOVE 100 mW IN THE USA. YOU PROBABLY WOULDN’T GET IN TROUBLE IF YOU DID, BUT BE A GOOD BOY OR GIRL AND OBEY ALL LAWS! The social contract depends on it!
Here’s some good gear you’ll need to get started. Total price, $250:
$170 Transmitter with roof kit antenna:
Bundle Deal: Fail-Safe 0.5 W Long Range FM Transmitter + 1/4 Wave GP Antenna Kit. Includes 30 foot FREE BNC Male-to-male cable. Power settings able to change from 500 mW to 100 mW:
The power cable on these transmitters is too short, like less than two feet. You may need an extension cord, but you probably already have one.
$50 Ramsey FMLP1WT Broadcast FM Low Pass Filter (says “Kit”, but is already assembled).
Accessories you WILL NEED:
$9 Dual Shielded Coaxial Digital Audio Video Cable – F-Connector to F- Connector with Easy Twist Caps – (8 feet)
THINGS YOU WILL NEED BUT MAY ALREADY HAVE:
–$8 Male-to-male stereo audio cable 3.5 mm to plug computer or iPod into transmitter.
Only use a stereo audio jack to plug into the transmitter. A mono jack will mechanically damage the female jack in the unit.
–Computer or iPod to play your programs from.
SOME TIPS FOR PROPER USE:
NEVER power up your transmitter without a proper antenna attached! Powering up your transmitter without a proper antenna attached will damage the transmitter. Use a proper antenna only, or you will damage your transmitter. Both the short “rubber ducky” antenna (it looks like the antenna on a walkie-talkie) that comes with these transmitters, and the ¼ wave antenna listed, are proper antennas for all of the transmitters listed here.
NEVER run an FM radio receiver in the same room with the transmitter. Same house should be OK, but in the same room can harm the receiver. Running other electronics should be fine, but don’t run an FM radio receiver in the same room as the transmitter.
To adjust the power on these little Chinese transmitters from 500 mW (not legal in USA) to 100 mW (probably legal in USA, depending on your antenna and other factors), here’s all you need to do: Push in and hold the power-on button then plug in the power cord the LCD will read “H” (high, 500 mW). By using the frequency up & down buttons you can switch to “L” (low, 100 mW), then unplug the power cord, then plug it back in and power on and you are now broadcasting at low power.
Legally I have to recommend that you don’t turn the power up to 500 mW unless it’s the zombie apocalypse and you have to warn your neighbors of the threat. 100 mW can give you a range of less than a block (with rubber ducky antenna indoors). It can reach about two blocks in all directions (with rooftop ¼ wave antenna). 500 mW can reach about 4 blocks (with rubber ducky antenna indoors) and over a mile and a half to two miles with a rooftop ¼ wave antenna. (That’s line of site with the antenna. It more or less stops dead when it hits a big hill or a line of tall buildings.) In an urban area, two miles each way is 16 square miles which is is potentially 250,000 people who live within the broadcast area, plus many more who drive through (and may be stuck in traffic if you live near a freeway). One of these transmitters can cover a medium-sized college campus plus off-campus areas where students live, shop and hang out.
On the off chance you get a knock at your door, I would not let them in without a warrant, and one should stop transmitting. Do the same if you get a nastygram (cease-and-desist letter).
If you want to lower the chances of getting in trouble, you need to make sure you’re being a good neighbor to your fellow broadcasters (and to your neighbors. If you don’t follow all of this, you could even interfere with cell phones, wireless internet and ham radio operators near your house):
1. Pick an open frequency. Here’s a site that helps you find one if you’re in the USA, searching by zip code:
Once you’ve found a frequency, you may want to drive around just to verify it’s clean. “Stepping” on an existing broadcaster is a sure way to get a visit from the goons. Treat your fellow broadcasters as you would like to be treated!
2. MAKE SURE THAT YOU ARE RUNNING THE LOW-PASS FILTER BETWEEN YOUR TRANSMITTER AND ANTENNA. Other than picking an open frequency, this is ABSOLUTELY THE MOST IMPORTANT THING I CAN TELL YOU. This prevents your transmitter from splattering itself all over different frequency multiples via “Harmonics”. Meaning, if you are operating a cheapie transmitter with no low-pass filter at 100MHz, then you are also broadcasting at 200MHz, 400MHz, and so on. This is NOT being a good neighbor, and you may be interfering with other communications on other bands even though 100MHz might have been a clear channel.
All the small made-in-China transmitters listed here are incredibly inexpensive, and represent a great leap in technology and price from any previous transmitters that can solidly hold on one station with no drift. They are cheap, but they do NOT have built-in low-pass filters, so you need to add one between the transmitter output and the antenna.
The Ramsey FMLP1WT listed above is a very good low-pass filter, even though it kinda looks like a fish tank filter, lol.
It requires no external power and does not need adjusting. It has no polarity, so it doesn’t matter which side you connect the antenna into and which side you connect the transmitter output into. Use the low-pass filter even if you’re using the rubber ducky antenna, but ESPECIALLY if you’re using an external ¼ wave antenna.
3. Don’t have your audio output volume too high from the computer or iPod that’s running into the audio input of the transmitter. Check the volume of transmission on a car radio a block from your transmitter. It should be comparable with commercial stations. NEVER louder. Audio material with consistent dynamics, i.e. a close-to-even volume, is better to use than audio material with lots of dynamics.
Don’t use material with cussing, that’s what gets people shut down. The gub’mint doesn’t actively monitor the airwaves, they generally only act on complaints. If you’re not cussing and not interfering with another station (remember, pick an empty frequency and USE A LOW-PASS FILTER!) you’d likely be OK. The goons are mostly busy chasing down cell phone jammers these days anyway. The goons generally issue a cease-and-desist letter for the first few infractions, then threaten fines. They really don’t want anyone to take it to court, for fear it will make it to the Supreme Court and they might lose on First Amendment grounds, which would open a hornet’s nest for them, and spread a lot of liberty.
Using music by other artists might get you a copyright lawsuit. The best thing to transmit is either talk radio and music you produce, or talk radio and music produced by people who don’t mind if you broadcast it.
Tuning your antenna:
“Tuning” your antenna (adjusting the height) helps maximize transmission. You adjust it based on the frequency you’re transmitting at. The rubber ducky antenna is not tunable. But the ¼ wave antenna is, simply by making the top, and the bottom (the radials), taller or shorter. Here is a link to a short PDF on how to tune it for all the different frequencies.
WHAT TO BROADCAST if you don’t have your own material, or enough to fill 24-7.
This podcast, the Freedom Feens
is the very best an-cap liberty podcast in the world. It’s funny, smart, has a large following, and is produced with very high audio quality, and with limited dynamics, which is perfect for radio. It’s also released copyright-free, Creative Commons, so it’s cool with them if you broadcast it. They’ve actually mentioned on their shows that they’re cool with people sharing it anywhere, any time.
Some Freedom Feens episodes have cussing. If you want only the non-cussing episodes, they’re all here on the Feens’ drone-proof bunker site in the Czech Republic:
Some of the newer episodes are also non-cussing, listen to find out.
Also good is the Liberty Radio Network’s streaming feed:
LRN is like the libertarian/an-cap NPR, in that it’s 24/7 of well-produced, great and varied programming. And in that some people like to leave it on in the background all the time. But unlike NPR, LRN actually allows and encourages people to share it anywhere they’d like.
An easy way to start would be to run a mix of Freedom Feens and LRN.fm most of the day, and do a one-hour show yourself one hour a week and then expand to one hour a day or more. These transmitters do have a microphone jack, or you can pre-record your show and drop the MP3s into the random mix with other people’s episodes. Here’s a good, inexpensive microphone recommendation, for $9. Here’s a post with much better mics, and some compressor/limiter options. A compressor/limiter will reduce the dynamics in your spoken material, which is a good thing for making a professional-sounding radio show and for not having a signal that will splatter on other stations. Here’s more on recording. It’s a very detailed post, but also has some good info for the beginner. Read the whole thing. And here’s a post on how to take phone calls on a live radio show.
You’ll get greater range if you have a good ¼ wave antenna vs. the rubber ducky. And greater range if your antenna is properly tuned, and if you can get it up as high as possible. An antenna outside a house will have better range than an antenna inside a house. An antenna on top of the house is best, though it could attract attention.
Some people have been known to camouflage an antenna inside of PVC pipe, which does not attract as much attention on a roof as an naked antenna on a roof. This is because roofs, especially in cities, often have various tubes and pipes sticking out of them. The PVC will not cut down much on transmission power, but it will protect the antenna from the elements.
Rubber ducky antenna inside a PVC housing.
If you have to have it inside, an antenna in the upper floors or attic of a building is better than on a lower floor. An antenna in the basement is horrible. Near a window is better than not near a window. Inside a wooden house is better than in a brick house.
An ideal location is any populated area, especially near college dorms or a near a highway with slow rush-hour traffic.
Stickers with your frequency, city, and some symbol of what you do, or the name of your show. Best to be mysterious and symbolic, to keep squares from groking what you’re up to. I don’t recommend graffiti, but I’ve seen it done. Also a small sign on a stick in the ground right next to a highway where there is slow rush-hour traffic. The sign could even just be the frequency number and “FM.”
If you run your transmitter 24/7, have a fan blowing on it to keep it from overheating. Put something under each edge of it so air from the fan can get under it, too.
iPods last about 12 hours, I don’t think they can be plugged in and run at the same time. You might want to run your media from a spare computer using iTunes or Windows Media Player or other player, set on random shuffle. It doesn’t take a very powerful computer to do this, so you can use the old one you replaced a few years ago.
I’d keep the antenna away from my head and pregnant women, but transmission health issues shouldn’t be much different from a cell phone. If you live in an area with a lot of lightning and you put the antenna on a high roof, you should have a lightning rod elsewhere on your house.
Some people run gear from a hidden public location or empty building and consider the gear expendable. Many people do this in the UK, and even leave a beer for the goon who finds it. They usually wipe all their fingerprints from the gear, though really motivated goons could probably locate the buyer based on serial numbers and credit card records. But hey, stuff get’s stolen. I suppose it’s possible that someone could actually file serial numbers off things, but I wouldn’t do it.
Do not use made up “call signs” (“KLSD”, “WEED”, etc.) You can name your show, but don’t give it alphabetical designations.
SISTERHOOD OF THE TRAVELING TRANSMITTER:
Several people in different areas could chip in and buy a system, and each run it for a few months, then pass it on to the next in the group, in a rotation. This would reduce costs, and reduce other issues, too.
OTHER NIFTY GEAR:
KIT OPTION FOR LOW-PASS FILTER:
Ramsey FMLP1WT Broadcast FM Low Pass Filter, as kit, saves 20 bucks if you’re good at soldering:
STRONGER TRANSMITTERS (for non-USA use). These all require an antenna, and the low-pass filter listed earlier:
$210 for a 1 W Fail-Safe Long Range FM Transmitter – TX-01S : Toggle from 0.1 W to 1.0 W Power Levels (ships without antenna) (range, 3 miles each way).
$240 Fail-Safe 5 Watt Professional Long Range FM Transmitter – TX-99A. (ships without antenna) (range, 6 miles each way).
$90 Fail-Safe 1/4 Wave Professional Grade Tunable Ground Plane Antenna (for transmitters that ship without an antenna):
25 foot male-to-male BNC cable (to go with the above antenna). $8.
Hope this post helps you in some way. Pass it on if you liked it. Radio is a RIGHT. And it’s plenty of fun for the whole family! Be safe, be legal (the social contract depends on it or we’ll degenerate into anarchy!), and most of all, ENJOY!
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