I've really been getting into web broadcasts for a huge variety of music. I have a little hp mini in my workshop that feeds the stereo system.
I live on two acres of property in a lightly populated rural area. I'd like to be able to xmit the station I'm currently listening to on an open freq so that I can listen via any portable FM radio that's handy for yard projects, working on my motorcycle out in the driveway, etc.
I did a little googling but am not really sure what might be the most appropriate, straightforward, and cheapest solution. Have seen many types of USB fm xmitters that I suspect are for very very short distance (same room). There are also the more involved fm xmitter standalone devices that are more powerful and expensive.
I might be wrong, but I suspect that a small fractional wattage xmitter for personal use like this is not bending any rules or requiring any paperwork.
Any suggestions?
I live on two acres of property in a lightly populated rural area. I'd like to be able to xmit the station I'm currently listening to on an open freq so that I can listen via any portable FM radio that's handy for yard projects, working on my motorcycle out in the driveway, etc.
I did a little googling but am not really sure what might be the most appropriate, straightforward, and cheapest solution. Have seen many types of USB fm xmitters that I suspect are for very very short distance (same room). There are also the more involved fm xmitter standalone devices that are more powerful and expensive.
I might be wrong, but I suspect that a small fractional wattage xmitter for personal use like this is not bending any rules or requiring any paperwork.
Any suggestions?
There are some legal transmitter kits sold here in the USA, (some by Ramsey) most of the ones sold on eBay have power levels that are too high to be legal.. I think something like 100mW is all that is permitted, however my recollection could be quite faulty, but as long as you are not interfering with others reception and the signal does not extend much beyond your property line you'll probably not have an issue.
You are correct that a small powered FM transmitter is legal as long as you don't exceed 25mW (approximately) and you don't interfere with any commercial stations.
Some of the units listed on eBay exceed the legal power limit and you could run the risk of getting a hefty fine from the FCC. If you stick to known brands, such as Ramsey and Decade, you shouldn't have a problem.
I have used both the Ramsey FM100B and the FM30B for setting up sound for hard-of-hearing at large events with excellent results. For the money, you can't beat the FM30B at around $200.00. It has an excellent s/n ratio and the oscillator is rock solid. Either unit can easily transmit a block away. Ramsey also makes a FM antenna that legally increases the transmit range.
The only drawback to the Ramseys is you have to assemble them. The Decades are more expensive but come assembled.
To find vacant channels, use this URL http://www.radio-locator.com/cgi-bin/vacant
Some of the units listed on eBay exceed the legal power limit and you could run the risk of getting a hefty fine from the FCC. If you stick to known brands, such as Ramsey and Decade, you shouldn't have a problem.
I have used both the Ramsey FM100B and the FM30B for setting up sound for hard-of-hearing at large events with excellent results. For the money, you can't beat the FM30B at around $200.00. It has an excellent s/n ratio and the oscillator is rock solid. Either unit can easily transmit a block away. Ramsey also makes a FM antenna that legally increases the transmit range.
The only drawback to the Ramseys is you have to assemble them. The Decades are more expensive but come assembled.
To find vacant channels, use this URL http://www.radio-locator.com/cgi-bin/vacant
I found the FCC limit for flea powered transmitters "Any unlicensed 88 to 108 MHz broadcasting with a signal strength greater than 250 µV/m at a distance of 3 m from the antenna is punishable by law and confiscation of all broadcast equipment."
This requirement is kinda tricky because it deals with the radiated signal instead of just the amplifier power. You could have a 1/2 watt transmitter and a lousy antenna and still be legal. However you could exceed the limit with a 1/4 watt transmitter and an efficient antenna.
This requirement is kinda tricky because it deals with the radiated signal instead of just the amplifier power. You could have a 1/2 watt transmitter and a lousy antenna and still be legal. However you could exceed the limit with a 1/4 watt transmitter and an efficient antenna.
It is tricky,and kinda screwy. Partly because no 'average Joe-radio' with a small transmitter kit can manage to afford a calibrated field strength meter ($$$) to ensure he is in compliance with the rules. It's sort of an impossible standard.
There was a paper somewhere online showing the signal strength at various power levels,using a basic half wave dipole antenna in an open field.
The Legal limit (in the US; 250uV@3meters) was reached with something like 15_nano_watts of power,IIRC. Basically,the FCC's limit is a gnat-fart's worth of power,You can get a signal a few hundred feet on a good day,if you're lucky.
(IIRC the Part-15 rules even state something along the lines of 250ft,or the edge of your property. -but don't quote me on that.)
The thing is,Most all of the kits sold (even ones type-accepted for Part-15 use in the US) have a couple dozen _milli_watts or so of output. With a half-decent antenna you can cover a couple blocks.
With a good antenna up somewhere high,and some low loss feed cable,people have been known to get out 1/4mile or more.
I'd think one of the various kits (Ramsey comes to mind) and some kind of antenna up in a tree/roof/attic you should be able to cover your target area nicely. Being in a rural area helps also,There's nobody around to complain to the FCC.
Some of the Ramsey kits even have adjustable RF power output,so you can dial it in for the coverage area you want,and no more,just to be extra careful.
There was a paper somewhere online showing the signal strength at various power levels,using a basic half wave dipole antenna in an open field.
The Legal limit (in the US; 250uV@3meters) was reached with something like 15_nano_watts of power,IIRC. Basically,the FCC's limit is a gnat-fart's worth of power,You can get a signal a few hundred feet on a good day,if you're lucky.
(IIRC the Part-15 rules even state something along the lines of 250ft,or the edge of your property. -but don't quote me on that.)
The thing is,Most all of the kits sold (even ones type-accepted for Part-15 use in the US) have a couple dozen _milli_watts or so of output. With a half-decent antenna you can cover a couple blocks.
With a good antenna up somewhere high,and some low loss feed cable,people have been known to get out 1/4mile or more.
I'd think one of the various kits (Ramsey comes to mind) and some kind of antenna up in a tree/roof/attic you should be able to cover your target area nicely. Being in a rural area helps also,There's nobody around to complain to the FCC.
Some of the Ramsey kits even have adjustable RF power output,so you can dial it in for the coverage area you want,and no more,just to be extra careful.
I was a little premature with this post perhaps. As usual, just coming up with the right search wording opened up the field considerably.
USB FM Transmitter - Enjoy online radio, music, and MP3, anywhere at home or office by using this extended range USB FM Transmitter - USB FM Transmitter
Amazon.com: Mac PC USB Wireless FM Transmitter 4 Home Stereo Audio: Electronics
Best Fm Transmitter: Bundle Deal: Fail-Safe 0.5 W Long Range FM Transmitter + 1/4 Wave GP Antenna Kit ($200 Value) Review
How to Use a FM Transmitter to Listen to Internet Radio | eHow.com
I'm clearly not the only one seeking to do this. So let me rephrase this since I'm here among the more technically competent. What would you choose? Or can you even conceive of a more elegant way of doing this? I don't mind using the workshop HP mini pc as a base. It's on all almost 24/7 anyway. So I don't need the flexibility of a stand alone unit that connects directly to the modem.
I was frankly hoping that I might discover a 39 dollar usb fm xmitter no larger than the typical wifi dongle that takes audio/power from the usb connection (without overriding the speaker-out feed via the headphone jack which is feeding the shop stereo). A little 5vdc powered FM stereo xmitter with an ext antenna plug that I could use to reach out a bit. (or just hardwire an ext antenna to its board)
USB FM Transmitter - Enjoy online radio, music, and MP3, anywhere at home or office by using this extended range USB FM Transmitter - USB FM Transmitter
Amazon.com: Mac PC USB Wireless FM Transmitter 4 Home Stereo Audio: Electronics
Best Fm Transmitter: Bundle Deal: Fail-Safe 0.5 W Long Range FM Transmitter + 1/4 Wave GP Antenna Kit ($200 Value) Review
How to Use a FM Transmitter to Listen to Internet Radio | eHow.com
I'm clearly not the only one seeking to do this. So let me rephrase this since I'm here among the more technically competent. What would you choose? Or can you even conceive of a more elegant way of doing this? I don't mind using the workshop HP mini pc as a base. It's on all almost 24/7 anyway. So I don't need the flexibility of a stand alone unit that connects directly to the modem.
I was frankly hoping that I might discover a 39 dollar usb fm xmitter no larger than the typical wifi dongle that takes audio/power from the usb connection (without overriding the speaker-out feed via the headphone jack which is feeding the shop stereo). A little 5vdc powered FM stereo xmitter with an ext antenna plug that I could use to reach out a bit. (or just hardwire an ext antenna to its board)
An externally hosted image should be here but it was not working when we last tested it.
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Keene USB FM Transmitter ? reghardware
...getting closer here.
Another neat part of using the dedicated mini pc for this is being able to greatly simplify the device, just a usb dongle, and handle the interface commands via the desktop where all my favorites and settings etc are located in the first place.. That one doesn't appear to have an external antenna option, but that's an easy workaround.
Please pass along any other ideas or links you have here.
...getting closer here.
Another neat part of using the dedicated mini pc for this is being able to greatly simplify the device, just a usb dongle, and handle the interface commands via the desktop where all my favorites and settings etc are located in the first place.. That one doesn't appear to have an external antenna option, but that's an easy workaround.
Please pass along any other ideas or links you have here.
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If I were seriously considering this, I'd go with something like the units available from Ramsey. Ramsey basically built their business with their transmitters. It's safe to say it ain't junk. Virtually any they offer can be had ready-built or as a kit. They may even have a good antenna to match. I'm sure they're not the only game in town, though, so a web search could find others.
I would then position the antenna and test my reception at the property boundaries, moving/raising the antenna until I had the coverage I wanted. Permanently install the antenna there.
I'd be concerned any $39 usb fm xmitter dongle would drift, be interference prone, have poor modulation, lo-fi sound, etc.
I agree, also, that about 25mW is the maximum power for a FM transmitter legally sold in the US.
this might be the info clearinghouse: hobbybroadcaster.net
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Why not DIY? Harry Lythall's website has a wealth of radio (and other electronics) projects and info. His V9 40mw FM transmitter looks ideal for your purposes. It's simple, cheap and has good frequency stability. There's even a PCB layout here in the download.
May I resurrect this thread to see if there are any more suggestions?
This is discussed in a recent thread....
VMR6512 HIFI Audio Transmition Board - Boards | Kits | Components | Modules | Tools
...which looks very very promising but I'd still like to find a USB 5vdc powered unit that I could control via the desktop GUI. I could easily solder an antenna to the board.
The Keene unit is now joined by a few others on the web, but thusfar I cannot seem to find any available for purchase in the US. Strange since a few of these higher powered (too powerful) standalone units are available here to anyone with a credit card.
These are avail on ebay for as little as 50 bucks. Selectable 100/500mw.
As mentioned in this thread there is a lot of room to adjust that to taste with more or less antenna attached to the back. This would certainly be the way to go unless I could find a good quality simple plug/play USB with desktop user controls such as frequency, a few xmission power levels, etc. Whether any of these sport such features is a mystery.
It's a year after I posted this originally and I'm still surprised that this is such a difficult thing to accomplish via USB. As far as I can tell, none of the commercial units below are available for me to purchase.
Here is the Keene
And a few others....
...avail here USB Mono FM Transmitter but mono and i'm frankly not that into that much work for so primitive a tool.
here...Electronics-Lab.com Blog Blog Archive FmStick Digital USB FM Transmitter
...so why, if i keep seeing these introduced as kits and schematics on the web is it so difficult to find one for purchase ready to go?
...and another .... with links to schematics.....
USB FM transmitter circuit
Actually lots more of these little things out there, but cannot find a single source for purchase.
This is discussed in a recent thread....
VMR6512 HIFI Audio Transmition Board - Boards | Kits | Components | Modules | Tools
...which looks very very promising but I'd still like to find a USB 5vdc powered unit that I could control via the desktop GUI. I could easily solder an antenna to the board.
The Keene unit is now joined by a few others on the web, but thusfar I cannot seem to find any available for purchase in the US. Strange since a few of these higher powered (too powerful) standalone units are available here to anyone with a credit card.
These are avail on ebay for as little as 50 bucks. Selectable 100/500mw.
As mentioned in this thread there is a lot of room to adjust that to taste with more or less antenna attached to the back. This would certainly be the way to go unless I could find a good quality simple plug/play USB with desktop user controls such as frequency, a few xmission power levels, etc. Whether any of these sport such features is a mystery.
It's a year after I posted this originally and I'm still surprised that this is such a difficult thing to accomplish via USB. As far as I can tell, none of the commercial units below are available for me to purchase.
Here is the Keene
And a few others....
An externally hosted image should be here but it was not working when we last tested it.
...avail here USB Mono FM Transmitter but mono and i'm frankly not that into that much work for so primitive a tool.
here...Electronics-Lab.com Blog Blog Archive FmStick Digital USB FM Transmitter
...so why, if i keep seeing these introduced as kits and schematics on the web is it so difficult to find one for purchase ready to go?
...and another .... with links to schematics.....
USB FM transmitter circuit
Actually lots more of these little things out there, but cannot find a single source for purchase.
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I lost all the images to the above post when posting. After three attempts to replace them. I eventually tried disabling ALL plugins in Firefox browser and still it ate my image uploads and refused to save them from session to session. I finally opened my unsecure Kmeleon browser, replaced all the images again, only do run into the admin's 30minute limit on editing posts. AAAARRRGGGGGHHH.
No big deal. You get the idea.
Im so damn fed up with Firefox security plugins screwing with me. I've been trying to get them tweaked for months now and am just FRUSTRATED with how unpredictable they are. I'm ready to let the bad guys just track me and infect my system and the rest just so I can go back to computing again with 1/10 the hassle.
Here is the original
No big deal. You get the idea.
Im so damn fed up with Firefox security plugins screwing with me. I've been trying to get them tweaked for months now and am just FRUSTRATED with how unpredictable they are. I'm ready to let the bad guys just track me and infect my system and the rest just so I can go back to computing again with 1/10 the hassle.
Here is the original
May I resurrect this thread to see if there are any more suggestions according to my original needs?
This is discussed in a recent thread....
VMR6512 HIFI Audio Transmition Board - Boards | Kits | Components | Modules | Tools
...which looks very very promising but I'd still like to find a USB 5vdc powered unit that I could control via the desktop GUI. I could easily solder an antenna to the board.
The Keene unit is now joined by a few others on the web, but thusfar I cannot seem to find any available for purchase in the US. Strange since a few of these higher powered (too powerful) standalone units are available here to anyone with a credit card.
These are avail on ebay for as little as 50 bucks. Selectable 100/500mw.
As mentioned in this thread there is a lot of room to adjust that to taste with more or less antenna attached to the back. This would certainly be the way to go unless I could find a good quality simple plug/play USB with desktop user controls such as frequency, a few xmission power levels, etc. Whether any of these sport such features is a mystery.
It's a year after I posted this originally and I'm still surprised that this is such a difficult thing to accomplish via USB. As far as I can tell, none of the commercial units below are available for me to purchase.
Here is the Keene
And a few others....
....as well as some diy such as...
USB Mono FM Transmitter but mono and i'm frankly not that into that much work for so primitive a tool.
here...Electronics-Lab.com Blog Blog Archive FmStick Digital USB FM Transmitter
...so why, if i keep seeing these introduced as kits and schematics on the web is it so difficult to find one for purchase ready to go?
...and another .... with links to schematics.....
USB FM transmitter circuit
Actually lots more of these little things out there, but cannot find a single source for purchase.
Any ideas?
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Not a cell phone user, believe it or not. But that would an interesting option. At least is goes some way toward explaining why my quest for a transmitter may be considered a bit quixotic in 2012. I'm practically the last guy in town without a smart phone. But I'm also kind drawn to the old-school appeal of being able to tune in, anywhere around my property, to any web streaming via any vintage FM radio that I happen to find at Goodwill. Extreme fidelity isn't even much priority. Just solid signal.
Seems since last year (at least since I wrote the posts above) a couple of these usb fm xmitters have shown up on ebay.
USB2.0 FM Audio transmitter Wireless adapter | eBay
Wireless USB 2.0 *FM Audio transmitter*adapter PC | eBay
Less than 10 bucks free ship. Worth the experiment. Has what I described. Plug and play with a desktop GUI. Should be breeze to tap an ext antenna onto the board.
On the page for the second one is the following description.....
Is usb by itself capable of feeding streaming audio to a transmitter?
But I'm also kind drawn to the old-school appeal of being able to tune in, anywhere around my property, to any web streaming via any vintage FM radio that I happen to find at Goodwill. Extreme fidelity isn't even much priority. Just solid signal. Seems since last year (at least since I wrote the posts above) a couple of these usb fm xmitters have shown up on ebay.
USB2.0 FM Audio transmitter Wireless adapter | eBay
Wireless USB 2.0 *FM Audio transmitter*adapter PC | eBay
Less than 10 bucks free ship. Worth the experiment. Has what I described. Plug and play with a desktop GUI. Should be breeze to tap an ext antenna onto the board.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
On the page for the second one is the following description.....
This is a mistake... no? I'm pretty sure that the only cable supplied with these is a short USB/USB extension. The other unit looks pretty identical and clearly it only has a USB/USB extension and mentions nothing about requiring the laptop's 3.5 mini stereo output for audio feed.
Is usb by itself capable of feeding streaming audio to a transmitter?
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Got to share this with you guys since it's kind of the perfect ethos for this forum. It's kind of DIY, though not deeply and involving board work or anything, it's surprisingly effective, and it's CHEAP, It took an hour to set up as follows once it arrived in the mail.
I did some "due diligence" on the FCC's concerns and discovered that the number people prosecuted for this type of use is exceedingly rare. There were a few hundred cases investigated last year. Of those a couple of dozen resulted in confiscation of equipment. And then only a smaller number than that, less than half a dozen, were prosecuted and fined. Those prosecuted were broadcasting at far higher wattage than this and primarily evading licensing in the first place in order to broadcast illegal/subversive/political content.
There are literally thousands of LPFM xmittiers (low power) in use by real estate agents using "smart home" xmitters for passersby to tune in and learn more about the property, in car xmitters for portable mp3 players to integrate with car radios, Christmas decoration enthusiasts who, like the realtors, put out signs for passersby to tune to musical accompaniment of their shows, and then many hundreds of "whole house" xmitters with generally more powerful settings available than the one I'm describing here.
So... disclaimers out of the way.....
12 dollars total. Seven for the usb xmitter, shipping is free. Two dollars for a Goodwill rabbit ears any day of the week. Two bucks for Monoprice 12 ft USB extension cable (had on hand from an older years ago).
Ebay Link
http://www.ebay.com/...=item35b4f84c54
GUI
http://images52.fotk...0209/FM1-vi.gif
GUI
http://images15.fotk...0209/FM2-vi.gif
Package Contents
http://i802.photobuc...at/SDC14265.jpg
Antenna was tucked under metal side clasp
http://i802.photobuc...at/SDC14268.jpg
Bare wire end was simply clasped behind the metal side clip. I noted during operation that minor hum was eliminated simply by grounding the metal clip with my fingers. When unit was properly soldered to rabbit ear leads and USB connected hum eliminated completely
Top of board
http://i802.photobuc...at/SDC14269.jpg
Bottom of board
http://i802.photobuc...at/SDC14270.jpg
Bottom closeup left
http://i802.photobuc...at/SDC14280.jpg
Bottom closeup right
http://i802.photobuc...at/SDC14279.jpg
Top closeup right
http://i802.photobuc...at/SDC14277.jpg
Top closeup left
http://i802.photobuc...at/SDC14275.jpg
Unit soldered to rabbit ears and vertically hung in upstairs closet.
Common rabbit ears are an ultra simple, inherently balanced, di-pole antenna. Cut the twin flat lead, common to all of these antennas, as short as possible, soldered to the board of the xmitter. I hung it vertically in an upstairs closet out of the way of harm, extended the telescoping elements according to a dipole calculator online for 106.3hz and ran 12ft of USB through the floor down to the workshop and plugged into my HP mini 110. I Xmit on a freq as far from any local broadcasts as possible and set the xmit to pretty much stop at my 2 acre fence.
Set to 106.3 right now. I play webcasts, primarily Last.fm - Listen to free music with internet radio and the largest music catalogue online and listen to them anywhere in the yard, out by the firepit, out in the garage, anywhere in the house with really really surprisingly fine fidelity. No static, hum, or distortion with GUI settings at approx 3/4 full and laptop volume at 3/4. I expected 1/10 of this performance out of this cheap little sucker but it's just beautiful and clear on any fm radio and boombox I've used.
What damn fun this is to just plug Steve Earle, Peggy Lee, Grandaddy, Beth Orton, Brazially Forro and Samba, etc, etc, and just enjoy anywhere in the yard.
I did some "due diligence" on the FCC's concerns and discovered that the number people prosecuted for this type of use is exceedingly rare. There were a few hundred cases investigated last year. Of those a couple of dozen resulted in confiscation of equipment. And then only a smaller number than that, less than half a dozen, were prosecuted and fined. Those prosecuted were broadcasting at far higher wattage than this and primarily evading licensing in the first place in order to broadcast illegal/subversive/political content.
There are literally thousands of LPFM xmittiers (low power) in use by real estate agents using "smart home" xmitters for passersby to tune in and learn more about the property, in car xmitters for portable mp3 players to integrate with car radios, Christmas decoration enthusiasts who, like the realtors, put out signs for passersby to tune to musical accompaniment of their shows, and then many hundreds of "whole house" xmitters with generally more powerful settings available than the one I'm describing here.
So... disclaimers out of the way.....
12 dollars total. Seven for the usb xmitter, shipping is free. Two dollars for a Goodwill rabbit ears any day of the week. Two bucks for Monoprice 12 ft USB extension cable (had on hand from an older years ago).
Ebay Link
http://www.ebay.com/...=item35b4f84c54
GUI
http://images52.fotk...0209/FM1-vi.gif
GUI
http://images15.fotk...0209/FM2-vi.gif
Package Contents
http://i802.photobuc...at/SDC14265.jpg
Antenna was tucked under metal side clasp
http://i802.photobuc...at/SDC14268.jpg
Bare wire end was simply clasped behind the metal side clip. I noted during operation that minor hum was eliminated simply by grounding the metal clip with my fingers. When unit was properly soldered to rabbit ear leads and USB connected hum eliminated completely
Top of board
http://i802.photobuc...at/SDC14269.jpg
Bottom of board
http://i802.photobuc...at/SDC14270.jpg
Bottom closeup left
http://i802.photobuc...at/SDC14280.jpg
Bottom closeup right
http://i802.photobuc...at/SDC14279.jpg
Top closeup right
http://i802.photobuc...at/SDC14277.jpg
Top closeup left
http://i802.photobuc...at/SDC14275.jpg
Unit soldered to rabbit ears and vertically hung in upstairs closet.
Common rabbit ears are an ultra simple, inherently balanced, di-pole antenna. Cut the twin flat lead, common to all of these antennas, as short as possible, soldered to the board of the xmitter. I hung it vertically in an upstairs closet out of the way of harm, extended the telescoping elements according to a dipole calculator online for 106.3hz and ran 12ft of USB through the floor down to the workshop and plugged into my HP mini 110. I Xmit on a freq as far from any local broadcasts as possible and set the xmit to pretty much stop at my 2 acre fence.
Set to 106.3 right now. I play webcasts, primarily Last.fm - Listen to free music with internet radio and the largest music catalogue online and listen to them anywhere in the yard, out by the firepit, out in the garage, anywhere in the house with really really surprisingly fine fidelity. No static, hum, or distortion with GUI settings at approx 3/4 full and laptop volume at 3/4. I expected 1/10 of this performance out of this cheap little sucker but it's just beautiful and clear on any fm radio and boombox I've used.
What damn fun this is to just plug Steve Earle, Peggy Lee, Grandaddy, Beth Orton, Brazially Forro and Samba, etc, etc, and just enjoy anywhere in the yard.
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I hate the fact that the l a s t . f m link hyperlinks as a damn ad. Clever of them, but it looks like an endorsement. Sorry 'bout that. And the rabbit ear antenna idea i got from one of the Christmas decoration forums where it's commonly used to reach out to cars in the street.
I've been using this xmitter for a month now and there is no drift at all. Seems rock solid. As I said, the fidelity is pretty astonishing, and that's coming from a diyaudio member..... generally picky about such stuff.
I've been using this xmitter for a month now and there is no drift at all. Seems rock solid. As I said, the fidelity is pretty astonishing, and that's coming from a diyaudio member..... generally picky about such stuff.
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