Thanks for the info. I may go with a transmitter where I can turn the pre-emphasis off. I'm surprised this isn't an option on most. I've noticed that transmitters with RDS or multiplex inputs have BNC connectors. How would I go about feeding these BNC inputs through my sound card?
I bought >>this<< transmitter, which sounds phenomenal but is a total POS. It overheated out of the box despite good SWR. I had to strap a heat sink to it and put a high powered fan over the output final. This has worked ok but the transmitter will no longer transmit on higher frequencies. Just ones below 92.0 (approximately) and below.
Based on the specs, I'm looking for something at www.elecsky.com that will sound just as good, but offer the swr protection and heat protection. I really don't want another muddy sounding transmitter like the one I had before this one, which was an hlly 5w. Nor do I want something that is going to overheat and burn up.
I've seen in the specs stereo separation, audio distortion, etc. Based on these, can anybody point me in the right direction to get a transmitter with the same great sound I have now?: Here are the specs of my existing transmitter. Thanks.
Power supply voltage: DC-12V Current work: ?4A Frequency range: 76 ~ 108Mhz or 76-90mhz or 87-108mhz Frequency Step value: 0.1MHz Frequency stabilization way: PLL Frequency stability: ± 10 ppm (-10 ° C +60 ° C ) Frequency Modulation: ? ± 75kHz (100%) Work methods: continuous work Clutter and Harmonic: less than-60dB SNR: ? 75dB Stereo separation:-50dB Audio frequency response: 50 to 18000hz Audio distortion: <0.3% Modulation: 15% Input Level:-15dBV RF output impedance: 50 Ohm
I was able to solve all my issues by setting Breakaway to its defaults, setting pre-emph to 75 and turning on de-emph. Then I set my stereo mix to 100 and output soundcard to 50. I used the test tones to set the L/R Ref level which is at -2 db. I now have beautiful, loud sound coming through the radio, indistinguishable from commercial stations.
Before I was using the PEQ settings in breakaway and the graphics equalizer in stereo tool to correct the built in pre-emph on the transmitter. All I needed to do was check the de-emph option.
Definitely use pre-emphasis in the breakaway software and make absolutely sure your transmitter isn't using its own on-board. You should be able to tell easily by just running regular audio into your transmitter as is and if it sounds muddy as hell then you know there is no pre-emphasis built in. It's pretty obvious when you hear a transmitter on FM broadcast not using pre-emphasis. Sounds like a radio trying to come through a pillow. If it does sound normal w/o any processing then you know that it does have it and needs to be disabled in its circuitry. If that is impossible, then you need to run de-emphasis after breakaway.
This is my problem! I can run regular audio into the transmitter and it sounds just fine. Therefore the transmitter must have pre-emphasis built in. I'm assuming that most cheap transmitters on ebay, like HLLY, CHZ, ELE, etc have it built in so the average person can simply hook it up to any device and have decent sound. I wouldn't have the technical skills to disable it on the transmitter so I'll have to look into the de-emphasis route.
I currently use breakaway broadcast processor in conjunction with stereo tool in windows. I use the compressor and pre-emphasis on breakaway and have Stereo Tool running as a plugin. Stereo tool handles the stereo widening and I use the FM Calibration feature in it to cut down on those nasty highs that always cause me serious issues. This was a complete nightmare to configure correctly just because of all the settings. I also have a phase rotator and bass boost plugin running in breakaway.
The reason I was looking for something else is because the resultant audio has a "manipulated" sound to it. It just isn't natural like what you hear on regular FMs. It does actually sounds pretty good, considering my cheap setup, but isn't the loudest thing on the FM dial. I was very cautious not to cause over-modulation by using a radio very sensitive to it for calibration. Whenever over-modulation occurred, you could hear the stereo narrow on the radio speakers.
In breakaway, it says not use de-emphasis for FM or AM broadcasting and I don't think my transmitter has it built in. If it weren't for stereo tool, I'd never be able to use breakaway by itself because it causes such harsh, over-powered highs. I believe this is because it's designed for digital interfaces without the "roll-off" that most cheap or on-board audio sound cards cause. My transmitter only has an analog input so I'm forced to go the analog route which opens up a can of worms.
I have also tried the standalone version of stereo tool with it's FM presets. It works pretty well, but again, THOSE DARN HIGHS! Plus, what level do you set your stereo mix and sound card output to in Windows? I've always assumed 72 (slightly less than 3/4 like the distortion point on most stereo receivers).
My reason for going the OS X route was to see if there's anything else. AU labs seems to work if I leave the compressor off, turn the limiter on, set the low pass to 15k and lower the decibel level on the low pass to prevent, again, those harsh highs.
Has anyone used Apple's free AU Labs plugin (under OS X) for FM audio? It contains a high and low pass filter as well as a limiter and multiband compressor. I'm just wondering if anyone has experience with settings to make it as loud as possible.
I just recently decided to "hackintosh" my PC and dual boot Mountain Lion to see if there were any cool Mac tools for this.
Currently, I set the low pass to 15k and the high pass to 30 Hz. I also turned on the multiband compressor, but it doesn't seem to make things louder. It just cuts the mid range and elevates the bass. It also seems like the distortion point of the volume level is about 88% which is weird. Under windows I usually set everything to 72%.
It doesn't sound bad but seems like it could be better with some tweeking.
Lol There's been this SSID showing up in my list of wifi networks on my street. It has been there all day. I attempted to track it down using wififofum on my phone, which provides a radar like view of networks in the area. However, this program isn't too accurate. It's definitely close by but can't see any usual vehicles on my street.
If you google this, there's others that have seen similar networks.
Is it advisable to shut of my low range pirate radio for now? I have it scaled back to only cover about 1000 ft radius.
I just wanted to let people know about this since this helped me with a very annoying problem. I have an ELE fm transmitter which is a real cheap POS (don't buy these). As a result, I had this really annoying 60 Hz buzz in the audio when it was connected to my computer. Other transmitters I've used on the same desktop haven't had this problem.
Anyway, I was able to solve it with a $20 ground loop isolator from radio shack. You can also get them online (like Amazon) for around 10 bucks. This fixed the problem completely. During periods of silence I now really do have silence on the other end.
The best part it is doesn't affect the music or audio quality. All audio frequencies go through just like they did before. I can even play a 60 Hz test tone and it still goes through loud and clear.
Cool thanks! I ordered it and will attempt to repair this transmitter. I just need to figure out how to keep the output final cool since I destroyed the case.
I busted up the output final on one of my transmitters trying to mount it to a heat sink. Is this the correct replacement? It says RD15HVF1 on it but there's some more numbers that don't necessarily match up. (103AA-G).
Am I correct in understanding that the wideband input is built into the 1/4 '' analog input? I was able to configure my stereo software to generate the pilot tone, but the RDS still doesn't show up on the receiver.