First off I am not complaining about the audio of my radios, they sound about as good as anything out here. I just want better like I heard awhile back, transmitting out the Mohave desert on one of the lower channels. He sounded as clean and loud as a commercial AM radio station. I want to know what his trick was. A studio mic? A big a** tube amp underdriven for linearity? Modified AM MW broadcasting equipment? I am so sick of these 1kw splatter boxes around here, although some of them dont sound too terrible all they do is talk crap about how many KW they put out, one guy claims 10kw and I just wanna show them up so bad it aint funny. Any broadcast engineers? any ideas?
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commercial broadcaster grade audio?
- Thread starter towerdog
- Start date
I think Captain Kilowatt/Moderator is a broadcast engineer.
Lotsa guys these days running great audio on the CB band. Epecially on SSB; but some are doing it on AM too. Many of them are using modified Ham radios that have 5-6kc's of bandwidth on SSB/10kc's on AM. Lots of bucks are spent to get that kind of sound. Is it worth it? I think that some prestty nice changes can be done without spending more than $1000 to get that broadcast sound.
I do the eSSB thing on ch 38/LSB.
Got about $1000 or less into my sound system.
Wrote a series of five articles about this subject.
You can find it here:
http://www.worldwidedx.com/installa...itizens-band-radio-export-radio-part-1-a.html
Lotsa guys these days running great audio on the CB band. Epecially on SSB; but some are doing it on AM too. Many of them are using modified Ham radios that have 5-6kc's of bandwidth on SSB/10kc's on AM. Lots of bucks are spent to get that kind of sound. Is it worth it? I think that some prestty nice changes can be done without spending more than $1000 to get that broadcast sound.
I do the eSSB thing on ch 38/LSB.
Got about $1000 or less into my sound system.
Wrote a series of five articles about this subject.
You can find it here:
http://www.worldwidedx.com/installa...itizens-band-radio-export-radio-part-1-a.html
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Robb, thanks thats one killer writeup. If i had a magazine I would ask you if I could publish it.
I have seen preamps, mixers and high end mics cheap as dirt and passed them up, so tomorrow think I will go looking for church yard sales.
I found this too NU9N AM Transmitter Hi Fi Audio Modulation Processing
I have seen preamps, mixers and high end mics cheap as dirt and passed them up, so tomorrow think I will go looking for church yard sales.
I found this too NU9N AM Transmitter Hi Fi Audio Modulation Processing
Thanx!
Yup; that is a great site for 'non-voodoo audio'. That is high-end audio w/o using tube equipment. The 'voodoo guys' that use the tube stuff are on this site:
Index
I use a mix of solid state and tube equipment.
Tube equipment is a stone groove . . .
Although I got out of broadcasting nearly six years ago (God how time flies) I did spend 22 years in the industry. Robb is right in saying that good audio does not need to cost thousands of dollars but it does take a little know-how. First and foremost is that although you may transmit everything from 20Hz-20KHz it will mean nothing unless the guy on the other end has a receiver capable of reproducing that audio. Having said that, most CB's are wide enough in the IF section to pass everything needed for good VOICE communications. I stressed the word "voice" because a CB will never have true broadcast quality which to me really is 20Hz-10KHz for an AM signal and out to 20KHz for FM. Most microphones are limited in the amout of audio they pass as they are meant for voice comms so starting with a good mic is a good idea. It does not need to be a high end studio mic as long as it has a flat frequency response from about 15-20Hz to at least 10KHz. Next look at the microphone input circuitry of the radi
ften there are series chokes in the audio line.These are there to help eliminate RF but they also limit the high freq response of the audio amp.If you are not running really high power chances are you don't need them and they can be bypassed. Any series couping capacitors in the audio chain can be increased in value and using tantalum type capacitors is the way to go. Use at least one microfarad. Beyond this the only thing you can do is hope the IF is wide enough to pass the audio and if not then major surgery is required which I won't even go into here. It requires replacing the TX IF filter with a wider bandwidth unit. You can also increase the sound quality by using a microphone EQ to boost the freqs the radio filters out and this will work to some degree.The more bands it has the better. To properly set up truely GOOD audio requires more than just a radio check from someone on the air unless that someone really knows his stuff and is not one of the loud and proud crowd. Speaking of that crowd, keep all your mod limiters in place and forget this "one watt swinging to 20 watts" crap. Go for what AM is really meant to be with a 4:1 peak to average ratio. Four watts swinging to 16 is good or 100 swinging to 400 or whatever you run for power.I have seen guys that run racks, yes plural, of audio gear and all it gives them is a big head and an empty wallet. Stacks of EQ's compressors, limiters, and noise gates are more than even the broadcasters need or use. If you can find one look for an Inovonics 222 processor. It has a compressor/limiter/EQ all rolled into one. They appear on Ebay now and then for a great price as most stations dumped them years ago in favour of an Optimod unit. You will need an mic preamp for it howevere as they only accept a line level in and out and by line level I mean a typical +4 or +8 dB and not the normal -10 dB or less so labeled as LINE LEVEL on consumer products.
ften there are series chokes in the audio line.These are there to help eliminate RF but they also limit the high freq response of the audio amp.If you are not running really high power chances are you don't need them and they can be bypassed. Any series couping capacitors in the audio chain can be increased in value and using tantalum type capacitors is the way to go. Use at least one microfarad. Beyond this the only thing you can do is hope the IF is wide enough to pass the audio and if not then major surgery is required which I won't even go into here. It requires replacing the TX IF filter with a wider bandwidth unit. You can also increase the sound quality by using a microphone EQ to boost the freqs the radio filters out and this will work to some degree.The more bands it has the better. To properly set up truely GOOD audio requires more than just a radio check from someone on the air unless that someone really knows his stuff and is not one of the loud and proud crowd. Speaking of that crowd, keep all your mod limiters in place and forget this "one watt swinging to 20 watts" crap. Go for what AM is really meant to be with a 4:1 peak to average ratio. Four watts swinging to 16 is good or 100 swinging to 400 or whatever you run for power.I have seen guys that run racks, yes plural, of audio gear and all it gives them is a big head and an empty wallet. Stacks of EQ's compressors, limiters, and noise gates are more than even the broadcasters need or use. If you can find one look for an Inovonics 222 processor. It has a compressor/limiter/EQ all rolled into one. They appear on Ebay now and then for a great price as most stations dumped them years ago in favour of an Optimod unit. You will need an mic preamp for it howevere as they only accept a line level in and out and by line level I mean a typical +4 or +8 dB and not the normal -10 dB or less so labeled as LINE LEVEL on consumer products.
Just a note regarding the tube thing. I seriously challange anyone to be able to tell me the difference between identical setups, one solidstate and the other with a tube amp when used for communications service. The subtle differences are just that. Subtle. Even a trained ear can only tell the differences on certain types of music program when all else is equal. Solidstate devices and the operation of them have come a looooong way since the "revolution" that brought them into vogue over tubes. What was a reality 20-30 years ago is now mostly a perception of reality rather than reality itself.
I know you don't buy into the tube thing.
But as a guitarist/musician for many, many years before I got into recording and live sound, tubes are easily detectable to my ear. No self-respecting blues guitarist that I have ever played and recorded with - including bassists - would ever use a solid state rig. In recording, the tube preamps have a definable 'phat' sound that only the real high-end/ultra expensive solid state preamps could attempt to emulate. Tubes have always sounded better - and they always will - IMO . . .
I know you don't buy into the tube thing.
But as a guitarist/musician for many, many years before I got into recording and live sound, tubes are easily detectable to my ear. No self-respecting blues guitarist that I have ever played and recorded with - including bassists - would ever use a solid state rig. In recording, the tube preamps have a definable 'phat' sound that only the real high-end/ultra expensive solid state preamps could attempt to emulate. Tubes have always sounded better - and they always will - IMO . . .
Please read everything I said Robb. I have highlited the part you missed in bold text. I in fact said that the difference is negligible for voice communications service. I also said a trained ear can tell the difference on music material and I would not argue that a musician has a trained ear. I also stand by what I said regarding the advancement of solidstate devices but should have added "as used in the broadcast industry" as most of the stuff is beyond the scope of a communicator. We replaced several 12BY7 and 12AX7 audio amps with RDL STA-1 amps and saw an INCREASE in audio quality and noise floor. A lot of the quality increase was due to the elimination of impedance matching transformers required when using the tube amps and the ringing associated with transformers.
Some people's ears...yes...a Fet sometimes can fool the human earop:
I have heard my station recorded before and after a FET condenser mic was used, as opposed to a tube condenser mic sound. There was a gloss and a phat that the FET just didn't have. Needless to say, I was quite pleased with what I heard. I would spend more for more tube gear; but I think I have achieved the sound I was looking for with what I have and use now. Quite satisfied . . .
I read what you said.
I just defend tube usage - lol!
OK; I'll get off of my soapbox now.
On a different note.
Of course, a Ham radio running marginal quality outboard gear as opposed to the really high-end stuff will have a minimal but noticeable change for the better. You and I know that even the best Ham radio doesn't have the specs to support true/commercial broadcast sound. There are just too may limitations.. But what has changed when using outboard gear, is the overall perception of what sounds are being broadcast despite the fact that it is a Ham radio. It is better. But too expensive for what you get out of it after a price point.
Mic - MXL V69/new $240 - with a GE 5 Star 5751 tube NOS/$35
Behringer Mic pre 2200 - $110/new
Behringer DEQ2496 - $150/used. One half of this unit is used for parametric EQing; the other half for the compressor - set up as a limiter.
Behringer EX3200 - $80/used.
Six snap-on ferrite beads @ $2 ea - on the entire audio chain.
Home made PTT cable.
All cabling is Mogami . . . Waaaay less than $1000 total . . .
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Just for the record, although I defended the quality of current solidstate technology nowhere did I say that I don't "buy into the tube thing" as you said Robb. I very much prefer tubes as RF amplifiers and as audio amplifiers in modulator service for commercial broadcasting as well as in my vintage 80m AM station. The reasons are more than the subtle difference in quality one sees in communications service and includes simplicity as well as the nostalgia and WOW factor. After all, real radios do indeed glow in the dark.
Which comes down to the fact that CB radio or ham radio was never intended for other than just communications, typically by voice. Because of that, and because a full spectrum sound range is impossible to cram in to the signal bandwidths allowed for almost all voice communications allotments. Of course you could digitize the audio, cram that into a really narrower range and then expand it on the receiving end. The difference in cost is like a Ford Pinto and a Rolls Royce. The typical CB'er or ham might spring for that Pinto, but very few will ever have a Rolls as a daily-driver. I've seen Volkswagens with a Rolls Royce 'snoot' on them, and I like them. but it ain't never gonna be a real Rolls...
- 'Doc
(and with my ears, why should I care?)
- 'Doc
(and with my ears, why should I care?)
Some people's ears...yes...
I have heard my station recorded before and after a FET condenser mic was used, as opposed to a tube condenser mic sound. There was a gloss and a phat that the FET just didn't have. Needless to say, I was quite pleased with what I heard. I would spend more for more tube gear; but I think I have achieved the sound I was looking for with what I have and use now. Quite satisfied . . .
I read what you said.
I just defend tube usage - lol!
OK; I'll get off of my soapbox now.
On a different note.
Of course, a Ham radio running marginal quality outboard gear as opposed to the really high-end stuff will have a minimal but noticeable change for the better. You and I know that even the best Ham radio doesn't have the specs to support true/commercial broadcast sound. There are just too may limitations.. But what has changed when using outboard gear, is the overall perception of what sounds are being broadcast despite the fact that it is a Ham radio. It is better. But too expensive for what you get out of it after a price point.
Mic - MXL V69/new $240 - with a GE 5 Star 5751 tube NOS/$35
Behringer Mic pre 2200 - $110/new
Behringer DEQ2496 - $150/used. One half of this unit is used for parametric EQing; the other half for the compressor - set up as a limiter.
Behringer EX3200 - $80/used.
Six snap-on ferrite beads @ $2 ea - on the entire audio chain.
Home made PTT cable.
All cabling is Mogami . . . Waaaay less than $1000 total . . .
You guys are crazy! If you want really cheap I run this! Breakaway Broadcast Processor
Breakaway Broadcast $free
homemade radio shack microphone $5
and one cheap POS radio $0-$50
Computer $your on this site so you got one!
I run the output of my sound card directly into the modulation section of my radios, I use mostly a Galaxy or a Cobra 148.
Breakaway has some limitation but its a good start, If you want to get something better than Breakaway then for around $200 you can get Pro-Tools or Lexicon.
I bought a Lexicon Omega off Craigslist for $50 used, so for $50 I have more options that you could ever have with rack gear and best of all NO RFI INTERFERENCE!
You can do that too.
I think what you have found is fine. If it works for you, that is what counts. As far as RF getting into your connections, you still may well need some ferrite beads on all audio wires between the mic, computer, and radio. RF is an equal opportunity messer-upper.
A $5 mic is just that; a $5 mic. Consider room for improvement if your budget will allow. You may well be surprised with the results.
Ever heard of radio operator "4040 - on the dock of the bay" on CB/AM?
He is local in my neck of the woods. He uses a popular/high end recording software called 'Pro Tools' on his computer going into his Yaesu FT-1000MP. But he also uses an ElectroVoice RE-20 mic - about $300/used. Mics are the weak link. The better the mic; the better the overall sound . . .
I think what you have found is fine. If it works for you, that is what counts. As far as RF getting into your connections, you still may well need some ferrite beads on all audio wires between the mic, computer, and radio. RF is an equal opportunity messer-upper.
A $5 mic is just that; a $5 mic. Consider room for improvement if your budget will allow. You may well be surprised with the results.
Ever heard of radio operator "4040 - on the dock of the bay" on CB/AM?
He is local in my neck of the woods. He uses a popular/high end recording software called 'Pro Tools' on his computer going into his Yaesu FT-1000MP. But he also uses an ElectroVoice RE-20 mic - about $300/used. Mics are the weak link. The better the mic; the better the overall sound . . .
I don't use any ferrite beads I made audio patch cords out of coax, The mic i made with parts i had laying around i know there is some improvement in upgrading to a professional mic. My point was to have some decent audio for next to nothing if you have some spare radios/parts around.
I have chatted with that 4040 a few times he has a few options for hifi radios I really like how is 101 sounded!
My plan for the my Lexicon box is to have live watergate recording and editing right at my fingertips along with transmit processing.