I NEED to create a FM station that will only be powered up for less than an hour at a time on random days and times. My need is patriotic. I dont wish to say too much about why i need to do this, only that its used for good.
My main concern is amplification. I need a powerful rig right now with little to no money spent. I know that it will be difficult but i am resourceful. I do have some electronics background and am not afraid to build a kit if need be to save money.
Question. Can a car sub woofer amp be used to amplify an FM xmitter? If not, are there higher wattage kits i could build?
First thing to learn about all of this is there is no such thing as "little to no money" when it comes to the transmitter....unless someone just drops one at your doorstep. And if you want a transmitter that does what it is supposed to do and not clutter up the entire radio spectrum with junk or sound like crap, investment is inevitable.
Even a well stocked junk pile will require some level of monetary investment in something or another.
The "powerful rig" your looking for will require an antenna and coax and low pass filter able to handle the power level. The antenna can be built from lengths of copper tubing (lengths depending on frequency of operation). The low pass filter can be built for the power level as well, if you got both the experience and testing equipment to do that. The coax...again some considerable investment in high quality low-loss coax is a MUST at power levels above 25 watts. Anything else and your wasting the power as heat and leaks.
Antenna height is just as important. FM frequencies are "line of sight" so you need little to no obstructions between the transmit antenna and target reception zones. Basically, the higher the better. And you would be surprised at just how much as little as 5 watts can cover when the antenna is 40 feet or more above the ground clearing obstructions like trees, power lines and buildings.
There are certain things that should be avoided and taken seriously if you want to operate safely and trouble free (no surprise knocks/barge in's). The most important is to keep a low profile and don't go around bragging all over about it. Another, as I mentioned earlier is to have a transmitter that outputs a CLEAN signal..by that I mean well attenuated harmonics and NO spurious junk clutter and a transmitter that is ON FREQUENCY! Pick a frequency that is not sitting right next to a major commercial channel, or in between two major stations. Find a frequency out of the way, at least 3 or more channels away from any other station below and above your frequency of operation..if possible. This may not be doable in large populated ares, in which your best bet is to find a frequency away from the popular stations, usually below 92.1 Mhz (the non-commercial band).
The lower frequencies from about 95.1 on down propagate better at lower power levels due to the longer wavelength, and the antennas are not all that much larger from those required at the higher frequencies above 95.1. Less power is needed as well to reach the same coverage distance.
Your asking about high wattage amplifiers. What exactly will you be driving this high wattage amplifier with? Keep in mind that your "exciter", the unit that will be driving that high wattage amplifier, MUST and I repeat MUST output a CLEAN signal!!!! If it outputs crap, that amp will output crap as well and possibly go POOF trying to shove a nasty noisy signal through it.
There are schematics and resources all over the web to put together some pretty decent amplifiers. Note though that high powered amps require hefty power supplies and adequate drive levels to produce their designed output wattage. And at the output of that amplifier you need a good low pass filter of the 7 pole or more variant. The higher power levels the more poles you want. 7 pole is a standard I recommend for any system pumping 50 watts up to 200. Above 200 and your going to want at least a 12 pole or more. Schematics and resources abundant across the web using Google or other search engine.
And no..a car sub woofer amplifier won't work!!
Good luck and good hunting!
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Im not very expeiranced with FM transmition but i was like you i entered into pirate radio with little to no knowlage of transmitting equipment however i have a great knowage and skill with electronics and software development so i asumed it would be easy.
I started of with a cheap CZH-7c Transmitter and two coathangers that i made into a dipole (Really really bad) it wasnt tuned and used cheap tv coax. That alone cost me around £70 (110ish USD) And that didnt work well.
I then did some reaserch learned a bit about radio so i then put together a 50 watt PA the transistor alone cost me £36 (56ish USD) then i had to buy a heafty heatsink to keep the thing cool again more money.
And after all that the thing still creates a strong background noise (needs a lpf).
After a lot of reaserch ive put together a 120watt rig with the knowlage ive learned it has 5 pole LPF (soon to be a 7 pole) in total this rig alone cost me around £260 then you need good coax and a good tuned antenna.
Basicly what im trying to say is do loads of reaserch before you even attempt to build a rig or have somone do it for you otherwise youll end up doing what i did and spend loads of money on something that dosent work correctly.
But once you get a rig they dont take long to setup and get going my rig takes around 5 minuites to setup and get on air.
honestly im not after a crystal clear transmission. i wont be broadcasting for long. i wont be playing music. i will be broadcasting voice for a very short duration from a vehicle parked on a hill. once im done im gone.
i just need to figure out something that will work for my needs. disposable needs if need be.
even if its an mp3 fm xmitter ran through a car amp and into an antenna or something powered off a spare car battery.
is it even possible to use a car audio amp to boost the broadcast?
i have been tasked with walking over stations for a short period of time broadcasting a message. the message is very important. there is no money for this project BUT i do have some junk that might be of use.
i have a belkin fm transmitter. i have a 1000 watt car audio subwoofer amp. i have copper and coax, i have a volt meter and MANY computers.
can i connect the fm transmitter to the amp and into an antenna?
i have been tasked with walking over stations for a short period of time broadcasting a message. the message is very important.
Depending on certain things, it might not be as easy as it sounds to just "walk" over existing broadcast stations. It is also not a very sound idea to begin with. Let me explain why.
Recently, since about 2008, FEMA, in cooperation with PEP (Primary Entry Point) stations across the country have installed emergency communications systems that are completely self contained. At each one of these locations is another little gadget not widely publicized. "RLRR" systems. Remote Listening and Ranging Receivers. These things can tune in to any frequency of interest, any mode of operation, and in conjunction with others located in the area, can triangulate a signal source within seconds, all done via it's own network connectivity, which is also used to control the FEMA emergency stations.
These RLRR systems are tied in with local authority communications too. The intent was to be able to triangulate a signal from someone in distress, like a cell phone call or other communications like CB, HAM, 2-way "walkie talkie" stuff. They triangulate the signal source and send data to emergency centers. They are programed with a database of known existing stations and communication signal sources in certain bands, including the broadcast bands. They are in essence a part of the "snooper ear" monitoring of things brought about by the boogie man fear mongering government must monitor you and everything to keep you safe from terrorists.
These things are also interconnected with the FCC monitoring stations. !!!!
Be warned, blatant interfering with existing broadcast stations or any other authorized communications system is considered a form of terrorism per the Patriot Act and if I were you, I would stop before you dive into something your going to regret. Start "walking" on top of broadcast stations and all it takes is for one of these systems to catch that, kick on the others to triangulate your location and before you know it, a slew of black and blue's with pretty red and blue lights come heading directly towards your location. If you do what your describing here in a public access forum, which just for your info is in fact monitored and read by FCC and other agencies, you already tipped your hand and with a little further simple research, know your service provider and IP and place of residence.
Tread lightly friend. It isn't the 60's and 70's anymore where "walking" on stations was a piece of cake back then. Today all this wonderful digital instant communications you hold in your hand to text message and send pictures and yack to friends to facebook or twitter can be used against you with instant ability too.
can i connect the fm transmitter to the amp and into an antenna?
The car amplifier is for audio frequencies, not radio frequencies. It won't work at all. You need a radio frequency amplifier for the 6 meter VHF range.
Again, rethink about your idea/task before you end up sinking.
Good luck!
Peace!
K-ROCKS RadioOne
ZeroPointRadio
AM Stereo 1670
FM Stereo 92.1
Post by HighMountainRadio on Mar 18, 2018 11:27:32 GMT -6
Greetings !
I realize this info will be wayy outdated, but for the benefit of future readers, you can NOT use a RF power amplifier designed for the 6 meter amateur radio band to amplify RF signals within the 88-108 MHz FM broadcast spectrum, it will not work, UNLESS the 6 meter amplifier which works in the 50-54 MHz RF spectrum is re-worked, retuned for the FM broadcast band ! Also whatever solid state device or vacuum tube may be used in the 6 meter amplifier must be capable of working properly within the FM broadcast spectrum of frequencies ! Also others have asked if they could use a car audio amplifier as an FM broadcast band power amplifier. NO, this is impossible ! A car audio amplifier is just for that, AUDIO frequencies 20 - 20,000 Hz, NOT RADIO frequencies which are higher in frequency than the audio spectrum !
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
Can anyone help me with a Ramsey FM-100 question. Transmitter only displays the right channel when receiving a signal. The left meter does not display a signal. I am getting right and left speaker sound ( Mono ? ). Any help would be greatly appreciated. Thanks..... Chap
Post by HighMountainRadio on Jul 13, 2018 3:05:10 GMT -6
Greetings From High Mountain Radio Chappeo !
I suggest first determining if you have both the left and right audio coming into your Ramsey transmitter. Obviously if one channel is missing coming into the input of your transmitter, that is all that will be broadcast. Try plugging the cable, coming from your program source device, into an audio amplifier, left and right channel inputs, and determine if, indeed, both channels are there and working properly. If that is correct and both signals are present, then the issue lies with the Ramsey transmitter, and of course requires a different, albeit, similar troubleshooting approach. Let me know if I can be of any further assistance ! Welcome to the forum !! Have fun, learn !
73... Spooky... "Broadcasting From Somewhere High Atop The Remote Appalachian Mountains"
"Knowledge Is Always Made More Valuable By Sharing It With Others !" Always Remember To Be Kind ! True Greatness Often Has Very Humble Beginnings ! Help A Kid Out Today ! *** High Mountain Radio *** "Broadcasting From Somewhere High In The Remote Appalachian Mountains"
