Don't assume I'm one of those "people " I started this thread to learn and I have learned a lot...this isn't plug and play without cash and/or knowledge..thank you guys very much! I have seen a video by bells CB shop that had a good mic and art pre-amp that sounded real good..might be a beginners start for me?
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Easiest way to achieve hi fi?
- Thread starter Bearcat
- Start date
I love all the personalities coming out, yes? This is really and truly a great thread indeed.I hope to hear the passion on the air and not written on a forum.
Cheers,
CBPhreaker
Cheers,
CBPhreaker
Indeed a "gathering of the minds"!
Starting somewhere like this forum allows one to "open the door" for passionate creativity to flow!
Hearing some great on-the-air audio really sparked my interest in producing "hifi" (or just better quality) audio for my station.
If it wasn't for Machete in the Mojave,
Motor Mouth on the "central coast" of California, Stringbean, Audioman and others that caused me to fall out of my chair when I heard them boom into my receiver, I wouldn't be as interested in citizens band radio!
Like with most things I find interesting and would like to practice, I read a lot about the topic. After having gained a general idea and sense of direction for the desired outcome, and acquiring some theoretical knowledge a time comes when one must "jump in and get their feet wet" to apply some theory in real world practice.
I am truly happy I found WWDX, without you fellow forum members we could not have such a great learning community.
Thanks Guys ( & maybe a few Gals too? lol) for making this all possible. Also a big shout-out to the staff & moderators who help keep the ball rolling!
73
-LeapFrog
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Translation from Japanese D104-M6B Video
I've never translated technical stuff from Japanese to English so forgive me if Im not 100% correct. I will write the literal first then the translated meaning to English below the sentence.
Report from Yamanashi
Hello from where I live in Yamanashi, Japan.
Microphone is in a hard case.
This mic is well built and has a hard shell case
Let me listen
Im using the microphone with the stock electronics.
Im starting the test -
(no trans. needed)
This is a crystal microphone, the mic is amplified inside
The element of the D104 is a crystal type and has a built amplifier.
(Testing sounds from CB set)
I attached a condenser mic, this makes a special mic because you have to [power the] condenser mic
I put special electricity to condenser mic.
I removed the stock element and installed a condenser mic which requires a resistor connected to the 9volt + side of the battery and the other end of the resistor to the condenser mic.
This is an ordinary radio - nothing special
You can hear clearly the high and low frequency
Condenser mic make sounds very clear
[No trans needed]
This is a low sound, this is a high sound both sound very clear, Im testing
[No trans needed]
You can hear clearly the high and low frequency
Condenser element makes tones very clear
this is a low sound
this is high sound
Low and High sounds are very clear.
Im testing
[No trans needed]
Made in china. just a minute to take special wire out
Now, you can hardly hear the sound.
Sound is quite narrow
Not hifi
The mic is made in China. [There was no context to this statement so it seems to be alone] Let me show you the difference between elements. See, if I take out the condenser mic and use the stock element you can hardly hear the tone. Listen, this element (stock) doesn't produce any hifi at all. It's bandwidth is very narrow.
Now change to condenser mic, just experimenting
test, test ,test
This has a very attractive low sound
I put the condenser mic back in and the sound is totally different, you can really hear the low tones.
[laughter]-a singer can use for low voice
[ I think they are making reference to a popular singer in Japan but I'm not 100% sure who that is and they go on for a few min talking about the large range of the singer and how the modified mic would be able to reproduce the vocal range of the singer]
Astatic d104 can be changed to hifi - construction with condenser mic
price is 69.99 American dollars
Japanese money is about 3500 yen (about 35 - 40 dollars )
this is a mic for grown up only
It is a plastic mic but it's not a toy.
You can turn way up high sometimes, you can adjust 1 or 2 mm
The mic is hot but sounds good with the mic gain up, but even a 1 to 2 mm adjustment on the mic gain makes a difference. [ Im fairly sure based on the context that he means the comparison between the two elements but I think they have been drinking and they are not using complete sentences (which is common Japanese)
9volt battery is standard 104 mic can be made to hifi
don't throw away
ordinarily 4k hill
this is a very powerful mic
[give a phone number]
Whit a monitor is so easy to hear even your own voice
The unit uses a 9 volt battery. It can easily be a hifi mic with the installation of condenser element. But don't throw away the stock element, it may be good for something. After the modification the 104 sounds really good and gets rid of the 4k rise and now produces HIFI audio. It sounds really good on an external monitor.
Hope this helps someone!!!
CBPhreaker
I've never translated technical stuff from Japanese to English so forgive me if Im not 100% correct. I will write the literal first then the translated meaning to English below the sentence.
Report from Yamanashi
Hello from where I live in Yamanashi, Japan.
Microphone is in a hard case.
This mic is well built and has a hard shell case
Let me listen
Im using the microphone with the stock electronics.
Im starting the test -
(no trans. needed)
This is a crystal microphone, the mic is amplified inside
The element of the D104 is a crystal type and has a built amplifier.
(Testing sounds from CB set)
I attached a condenser mic, this makes a special mic because you have to [power the] condenser mic
I put special electricity to condenser mic.
I removed the stock element and installed a condenser mic which requires a resistor connected to the 9volt + side of the battery and the other end of the resistor to the condenser mic.
This is an ordinary radio - nothing special
You can hear clearly the high and low frequency
Condenser mic make sounds very clear
[No trans needed]
This is a low sound, this is a high sound both sound very clear, Im testing
[No trans needed]
You can hear clearly the high and low frequency
Condenser element makes tones very clear
this is a low sound
this is high sound
Low and High sounds are very clear.
Im testing
[No trans needed]
Made in china. just a minute to take special wire out
Now, you can hardly hear the sound.
Sound is quite narrow
Not hifi
The mic is made in China. [There was no context to this statement so it seems to be alone] Let me show you the difference between elements. See, if I take out the condenser mic and use the stock element you can hardly hear the tone. Listen, this element (stock) doesn't produce any hifi at all. It's bandwidth is very narrow.
Now change to condenser mic, just experimenting
test, test ,test
This has a very attractive low sound
I put the condenser mic back in and the sound is totally different, you can really hear the low tones.
[laughter]-a singer can use for low voice
[ I think they are making reference to a popular singer in Japan but I'm not 100% sure who that is and they go on for a few min talking about the large range of the singer and how the modified mic would be able to reproduce the vocal range of the singer]
Astatic d104 can be changed to hifi - construction with condenser mic
price is 69.99 American dollars
Japanese money is about 3500 yen (about 35 - 40 dollars )
this is a mic for grown up only
It is a plastic mic but it's not a toy.
You can turn way up high sometimes, you can adjust 1 or 2 mm
The mic is hot but sounds good with the mic gain up, but even a 1 to 2 mm adjustment on the mic gain makes a difference. [ Im fairly sure based on the context that he means the comparison between the two elements but I think they have been drinking and they are not using complete sentences (which is common Japanese)
9volt battery is standard 104 mic can be made to hifi
don't throw away
ordinarily 4k hill
this is a very powerful mic
[give a phone number]
Whit a monitor is so easy to hear even your own voice
The unit uses a 9 volt battery. It can easily be a hifi mic with the installation of condenser element. But don't throw away the stock element, it may be good for something. After the modification the 104 sounds really good and gets rid of the 4k rise and now produces HIFI audio. It sounds really good on an external monitor.
Hope this helps someone!!!
CBPhreaker
Tell me who is good with both this stuff and SMT so I can send them money.
A couple more quick questions:
#1, I have come across crystal filter "modules" that state that they can only be used in the receive signal path and not TX, it seems as though these modules all contain some type of signal amplifiers (often referred to as buffer amps). Am I correct in assuming that it's the amps that are the problem and not the crystal filters used? Are there any limitations on crystal filters that I should know about in this regard?
#2, I also vaguely remember reading that on RCI 29XX radios the 455khz filter is only used for receive and isn't inline during TX, any truth to this?
Thanks for any replies.
Tell me who is good with both this stuff and SMT so I can send them money.
A couple more quick questions:
#1, I have come across crystal filter "modules" that state that they can only be used in the receive signal path and not TX, it seems as though these modules all contain some type of signal amplifiers (often referred to as buffer amps). Am I correct in assuming that it's the amps that are the problem and not the crystal filters used? Are there any limitations on crystal filters that I should know about in this regard?
#2, I also vaguely remember reading that on RCI 29XX radios the 455khz filter is only used for receive and isn't inline during TX, any truth to this?
Thanks for any replies.
Not sure about the crystal filter modules or the RCI radios. On the cobra rigs the 455 filter is not used on TX. Most exports are probably the same. I do know that both TX and RX pass through the filter on the kenwood I mentioned earlier. It has to be changed or set up a relay to bypass it on TX.
If you can follow the schematic, you'll see the IF for the receive step through that filter then becomes receive audio. Transmit has a different mixing process. The only limitations you're facing with bandwidth is the caps placed in the path of the audio signal. Direct inject and be wide as you want to be.
Those radios sound great but 4000hz isn't wideband.
Neat test. I made it from 20hz to 16000hz before the peaks started to fall....23 year old cobra 29.
Neat test. I made it from 20hz to 16000hz before the peaks started to fall....23 year old cobra 29.
Last edited:
Not interested in efficiency. You can have quality or quantity....it did talk from Fort Worth to Lake Fork last night. I couldn't hear the guy at lake but he heard me. 309 in Michigan rolled the 5 for him. Anyway that's 100 miles as the crow flies. You only get 60 miles out of your radio don't you? Doesn't sound too efficient.
60 miles or so is about the best I couos get when I had my Nisan NV high back work van and running a Sirio 5000 performer magnet mount. Had extra magnets on the underside and used LMR240 coax instead of the stock rg58. Not that it makes much if any difference. Also had ferrite snap chokes at the mag mount. With 50 watts and my Optima MK3 I could make it right at 60 miles normally, that was on SSB and without of powerful DX going!! Otherwise forget it!! But under regular conditions I could hit 30-60 miles. And this was with a mag mounted antenna!! I did have the magnaforce 350hd in line with 2 toshiba 2879's in it that would help out a lot! But when Mother Nature let the floods gates open and the DX came in it was more fun talking to AU and all over the world while doing 70mph down the road!! Now I am in the rebuild stage of everything! Base included as Hurricane Matthew got us pretty good here around Daytona Beach, FL!! I took my Sirio vector 4000 down and just in time!! Hell my local pals 85ft large ROHN tower took a guyed wire hit and came down. 3 element beam and entire repeater system destroyed!! I plan on rebuilding a new mast setup and using LDF4-50A. Already have it ready to go!! Jist have to rebuild now. My antennna got a little bent as I took it down swiftly!! Didn't have much time as the storm turned very quickly and I had to make a last minute decision to take it down!! Glad I did. I can repair the bends!! Or get a new antenna. Just didn't need it to become a missile!!! Glad I took it down!! Anyways. Enough BS'ing!!! I'll be back on air soon. Better than before.
God Bless all those that spoke with me during the storm! Both before and after!!
. God Bless all those that spoke with me during the storm! Both before and after!!
The easiest way is to start with a tube radio or tube hybrid radio with an insanely wide band width to start with. The other way to go would be to look for radio's that used push-pull dual transistor setup in their audio modulator area before audio IC's like the 7222A came on the scene. These will be much easier to get the noise floor on receive and transmit down. They will be easier to modify the audio stage on with out having to get into all the other things because you do not have one IC handling all of them.
It is much easier to do this on AM only radio as well because you do not need to worry about AB bias than and you have less work to do with regard to filtering since SSB is not a worry. Not that you still do not need to worry about sub carriers and such but it makes the job a lot less complicated is all.
I have never done the so called hifi mod by goldfinger been looking at it and never done the "direct inject" mod that in vogue today but I have played around with injecting my signal at very stages in the audio chain in the past. usually it was because of really bad OEM design or a defect I was working around like obsolete parts and the fact I was using gear at times designed for broadcast industry and I could not always inject it right into the first stage. I will say that you are usually better off in my opinion leaving the limiters in place and injecting just ahead of the AGC/ALC. Depending on what you are trying to do and what the circuit looks like sometimes slowing down the AGC is best and sometimes speeding it up and making it more aggressive is the order of the day.
The problem with most modifications is that alot of times the people doing them have no gear besides a watt meter and a soldiering station. That is why I stoped doing modifications so long ago with out the gear to reference what I am doing I do not like just blindingly following a mod. Seldom does a recipe work from radio to radio usually things go best when you have the ability to fine tune the parts used on a radio by radio basis. I am slowly purchasing more gear to get back into doing more of my own work properly!
Moderation is the name of the game and in this hobby like so many other's the idea of "If a little bit is good a lot must be even better!" prevails. So people are not content to keep the negative peaks at 95% and have positives at 110% they have to have 140%, 180%, 200% 300% etc.......So then it is 6Mhz wide band width than it is 12Mhz then it is 17Mhz wide etc......Like anything they do not know when to stop and it ends up hurting the band really because once you go past a certain point the receivers can not even interpret the data being sent as useful info it just ends up becoming noise.
I am all for modest improvements that stock units can benefit from but once it get's to the point that it is causing interference to the band and to other's I think it has gone too far.
Also radio is about being able to communicate with another person. often times what makes for better DX-ing and better understand-ability is the opposite of what makes for a more broadcast like sound. Highs make us easier to understand but low's are what make us sound like a vintage DJ or Talk Radio personalities.
I sound like Darth Vader the last thing I need is more bass so I am always trying to get just a little more high's with out becoming a filtering issue and a splatter box. Darth Vader does not sound good on SSB or AM at a distance the crappy receivers, audio circuit and speakers in CB do not do Darth Vader any justice! LOL Everyone thinks they need more bass in their transmit audio but if you are man that went through puberty with out issues seldom is that true!
The people that make a habit of breaking what I think are reasonable modification seldom sound good most of the time. They sound good some of the time but not all of the time. The cost to play keeps going up as does the complication of it all with each step up the ladder. To do it properly is not cheap and is not easy and requires some technical understanding even to operate the gear well. A lot people good too far and create an RF landscape that is full of noise and interference. Likewise if other radio's can not benefit from what you are emitting than what is the point?
My guidelines would be
100hz to 5000Hz maybe as high as 6000hz on audio shifting the 6db down points to best suite your voice
At or bellow 140% positives 120% prob. no problem with negatives held to 95% with proper Asymmetric modulation.
At or bellow 6Khz bandwidth on AM
properly filtering so no harmonics where leaving the rf chain
not more than 100 watts rms rf power output
If people did this than we would not have so many issues. A radio like that could be rather simple to operate with no real need to monitor it constantly.
a lot of radio have a 6db down of 2000hz on AM with 1500-4000 being the total freq rang on the high side. On the low side 6db down is usually around 300 with total range in the 100hz-500hz ball park. Usually these numbers are generated with the modulation set around 30% with signal generator then they sweep the unit under these conditions. Usually the low side stays the same for all modes but the high side 6db down point will normally shift up an additional 1000hz on SSB and will normaly drop down 500hz lower on FM. I am being optimistic by the way a lot of CB are not passing as much as I am citing above. So it does not take that much to have a huge impact on how you sound. You do not need to have a unit that will pass 20hz to 15Khz to sound really really good. In fact that would be a huge waste of talk power for what we want to do on CB.
The above is just my opinion but given a lifetime of home audio and being a musician I think the above would be a fantastic compromise between what can be done and what would cause little interference if done. It could be made to be close to idiot proof in operation as long as golden screw drivers where left out and we did not allow anyone on channel 6 near the radio's. LOL
It is much easier to do this on AM only radio as well because you do not need to worry about AB bias than and you have less work to do with regard to filtering since SSB is not a worry. Not that you still do not need to worry about sub carriers and such but it makes the job a lot less complicated is all.
I have never done the so called hifi mod by goldfinger been looking at it and never done the "direct inject" mod that in vogue today but I have played around with injecting my signal at very stages in the audio chain in the past. usually it was because of really bad OEM design or a defect I was working around like obsolete parts and the fact I was using gear at times designed for broadcast industry and I could not always inject it right into the first stage. I will say that you are usually better off in my opinion leaving the limiters in place and injecting just ahead of the AGC/ALC. Depending on what you are trying to do and what the circuit looks like sometimes slowing down the AGC is best and sometimes speeding it up and making it more aggressive is the order of the day.
The problem with most modifications is that alot of times the people doing them have no gear besides a watt meter and a soldiering station. That is why I stoped doing modifications so long ago with out the gear to reference what I am doing I do not like just blindingly following a mod. Seldom does a recipe work from radio to radio usually things go best when you have the ability to fine tune the parts used on a radio by radio basis. I am slowly purchasing more gear to get back into doing more of my own work properly!
Moderation is the name of the game and in this hobby like so many other's the idea of "If a little bit is good a lot must be even better!" prevails. So people are not content to keep the negative peaks at 95% and have positives at 110% they have to have 140%, 180%, 200% 300% etc.......So then it is 6Mhz wide band width than it is 12Mhz then it is 17Mhz wide etc......Like anything they do not know when to stop and it ends up hurting the band really because once you go past a certain point the receivers can not even interpret the data being sent as useful info it just ends up becoming noise.
I am all for modest improvements that stock units can benefit from but once it get's to the point that it is causing interference to the band and to other's I think it has gone too far.
Also radio is about being able to communicate with another person. often times what makes for better DX-ing and better understand-ability is the opposite of what makes for a more broadcast like sound. Highs make us easier to understand but low's are what make us sound like a vintage DJ or Talk Radio personalities.
I sound like Darth Vader the last thing I need is more bass so I am always trying to get just a little more high's with out becoming a filtering issue and a splatter box. Darth Vader does not sound good on SSB or AM at a distance the crappy receivers, audio circuit and speakers in CB do not do Darth Vader any justice! LOL Everyone thinks they need more bass in their transmit audio but if you are man that went through puberty with out issues seldom is that true!
The people that make a habit of breaking what I think are reasonable modification seldom sound good most of the time. They sound good some of the time but not all of the time. The cost to play keeps going up as does the complication of it all with each step up the ladder. To do it properly is not cheap and is not easy and requires some technical understanding even to operate the gear well. A lot people good too far and create an RF landscape that is full of noise and interference. Likewise if other radio's can not benefit from what you are emitting than what is the point?
My guidelines would be
100hz to 5000Hz maybe as high as 6000hz on audio shifting the 6db down points to best suite your voice
At or bellow 140% positives 120% prob. no problem with negatives held to 95% with proper Asymmetric modulation.
At or bellow 6Khz bandwidth on AM
properly filtering so no harmonics where leaving the rf chain
not more than 100 watts rms rf power output
If people did this than we would not have so many issues. A radio like that could be rather simple to operate with no real need to monitor it constantly.
a lot of radio have a 6db down of 2000hz on AM with 1500-4000 being the total freq rang on the high side. On the low side 6db down is usually around 300 with total range in the 100hz-500hz ball park. Usually these numbers are generated with the modulation set around 30% with signal generator then they sweep the unit under these conditions. Usually the low side stays the same for all modes but the high side 6db down point will normally shift up an additional 1000hz on SSB and will normaly drop down 500hz lower on FM. I am being optimistic by the way a lot of CB are not passing as much as I am citing above. So it does not take that much to have a huge impact on how you sound. You do not need to have a unit that will pass 20hz to 15Khz to sound really really good. In fact that would be a huge waste of talk power for what we want to do on CB.
The above is just my opinion but given a lifetime of home audio and being a musician I think the above would be a fantastic compromise between what can be done and what would cause little interference if done. It could be made to be close to idiot proof in operation as long as golden screw drivers where left out and we did not allow anyone on channel 6 near the radio's. LOL
I think 4k highs is just enough to stand out of the crowd without going overboard.