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Got my Mauldulator today, WOW

Shockwave

Sr. Member
Sep 19, 2009
3,779
3,270
273
Well, it is very obvious this post was started to make sales for the mentioned product. How do you guys think that PC is gonna run next to the Heathkit SB-220? How many keys before the mouse locks up? People, there are much easier ways that cost less if your goal is Hi-Fi AM. I work 75 meter AM all the time and you'll never hear this gadget used there.

First of all, you would never want more then 200% positive peaks for a very simple reason. The AM detectors used in every CB radio will not be able to demodulate this level of audio without distortion. Only a synchronous detector can do this. You'll notice the Mauldulator requires the use of a quality mic. You can't use your D-104 because it doesn't have Hi-Fi. The mic is 90% of Hi-Fi.

The rest is mainly making sure the coupling caps used in your radios audio chain are made larger to increase bass response. Most CB's will not have very much limitation in the high end but there may be bypassing caps in parallel that block the highs. A simple passive audio notch filter tuned around 500 Hz will give that FM sound with the right mic. This gets rid of that low end mid range that tends to sound "muddy". The filter is nothing more then a coil in series with a cap that is placed across the audio line. Many DC relay coils with 750 ohms resistance work great for this with a .1 mfd cap in series.

You can make a Hi-Fi mic out of an old Astatic 1104C or 575M6. The FET pre amp and tone control are ideal for modification. Rip out that ceramic element and replace it with any 2 wire electret condenser. These cheap mics have excellent response. The brown wire goes to the element ground. Take a .01 mfd cap and put it in series with the green wire to the element positive to block the DC. Then use a 33K resistor from the 9 volt battery + terminal directly to the positive terminal of the electret to supply bias. The mic switch disconnects the - side of the battery in RX and will shut the element off too.

If you want to take this further then use the passive notch filter I described above and place it right across the back of the electret element. Coil side to ground and cap side to hot. Even without doing any internal radio work, this mic will make a big difference in audio quality without any of the RFI problems associated with the external equipment this Mauldulator uses. If you're technical then get out your radios schematic and go after the audio coupling and bypassing caps.

Just keep your carrier around 25% (or slightly less) of your radios total PEP output and you'll be rockin loud and clear. SSB radios work best for this mod since they have carrier level control. Remember, electrets need a wind screen in front of them otherwise they become distorted from breath pops. The original Astatic foam or cotton works fine. This setup on my Kenwood TS-940SAT produces better audio quality then most AM broadcast transmitters. Yes, the Kenwood is heavily modified and no longer uses low level IF modulation in AM. The mic amps have been modified for flat response and the modulation takes place in an RF stage.
 
Last edited:

wahlrite

Member
Jul 19, 2008
68
1
16
Well, it is very obvious this post was started to make sales for the mentioned product. How do you guys think that PC is gonna run next to the Heathkit SB-220? How many keys before the mouse locks up? People, there are much easier ways that cost less if your goal is Hi-Fi AM. I work 75 meter AM all the time and you'll never hear this gadget used there.

First of all, you would never want more then 200% positive peaks for a very simple reason. The AM detectors used in every CB radio will not be able to demodulate this level of audio without distortion. Only a synchronous detector can do this. You'll notice the Mauldulator requires the use of a quality mic. You can't use your D-104 because it doesn't have Hi-Fi. The mic is 90% of Hi-Fi.

The rest is mainly making sure the coupling caps used in your radios audio chain are made larger to increase bass response. Most CB's will not have very much limitation in the high end but there may be bypassing caps in parallel that block the highs. A simple passive audio notch filter tuned around 500 Hz will give that FM sound with the right mic. This gets rid of that low end mid range that tends to sound "muddy". The filter is nothing more then a coil in series with a cap that is placed across the audio line. Many DC relay coils with 750 ohms resistance work great for this with a .1 mfd cap in series.

You can make a Hi-Fi mic out of an old Astatic 1104C or 575M6. The FET pre amp and tone control are ideal for modification. Rip out that ceramic element and replace it with any 2 wire electret condenser. These cheap mics have excellent response. The brown wire goes to the element ground. Take a .01 mfd cap and put it in series with the green wire to the element positive to block the DC. Then use a 33K resistor from the 9 volt battery + terminal directly to the positive terminal of the electret to supply bias. The mic switch disconnects the - side of the battery in RX and will shut the element off too.

If you want to take this further then use the passive notch filter I described above and place it right across the back of the electret element. Coil side to ground and cap side to hot. Even without doing any internal radio work, this mic will make a big difference in audio quality without any of the RFI problems associated with the external equipment this Mauldulator uses. If you're technical then get out your radios schematic and go after the audio coupling and bypassing caps.

Just keep your carrier around 25% (or slightly less) of your radios total PEP output and you'll be rockin loud and clear. SSB radios work best for this mod since they have carrier level control. Remember, electrets need a wind screen in front of them otherwise they become distorted from breath pops. The original Astatic foam or cotton works fine. This setup on my Kenwood TS-940SAT produces better audio quality then most AM broadcast transmitters. Yes, the Kenwood is heavily modified and no longer uses low level IF modulation in AM. The mic amps have been modified for flat response and the modulation takes place in an RF stage.

You are correct shockwave, but you cant get the tube emulation, and the big swing numbers like the mauldulator can.

and you can NOT get a cb to pass 80 to 6000 Hz, with out the mauldulator.

Wahlrite
 
B

BOOTY MONSTER

Guest
who would have ever thought such words of wisdom would have resulted from this thread .
if you cant dazzle them with brillance , then baffle them with bullshit .
 

Slam Dunk

Member
Jul 11, 2006
79
0
16
Time To Call Bull Shizzzz?

ButtFuzz,

I am new to the high fidelity stuff so I can not answer your question regarding the 3Khz stuff.

Here in the town I live in AM broadcast radio sounds kinda plane, flat, mono sounding, like the same sound a CB makes and the FM broadcast stations sound full, rich and warmer and I can hear a lot wider range of sounds very clearly as compaired to Am, thats whay I used that as a compairison.

If you can clarify your question I would be glad to ask the guy that makes it and get back to you.

Wayne

Thanks Slam Dunk,
And that for the intelligent response and info, I have just recently received a mauldulator from motor mouth maul, I heard him on the air and immediately fell in love with the sound his stuff produced.

I have not been into radio stuff for very long, I owned a professional recording studio for many years and I have a very good, pitch correct ear.

This is the reason I decided to purchase the mauldulator radio, Of all the radios I have heard, this one smokes them all, buy a long shot.

If you have a few extra minutes please check out the cbtricks web page under new product showcase, this is where I first saw the item and started learning about it, and let me know what you think.

The version I got was the one with the cobra 29, and as advertised, it puts out exactly 3/4 watt @ 200% modulation without exceeding 100% in the negative direction, and again im new to this so im just repeating what I have read from my experience with this thing.

It came all put together, and ready to go.

and yes I know that each pl-259 connection reduces the Db of my signal, Im actually one of thoes wierd people that does not run a watt meter inline all time, unless im testing something.

as far as the highly suppressed carrier stuff, I dont really know if my signal is highly suppressed, so I dont have a response for you on that but I will call motor mouth and ask that question.

I like the small 1 pill you have installed in the back of your radio, would you be willing to give details ?

thanks for the input, again, Im just trying to learn and move forward in a positive direction.

Thanks

Wahlrite

sorry for the BULL with fatty, but I have read alot of his post and it just seems like hes more interested in bashing everyone. what I need to do is stop responding to that stuff.

I-I-I-I think that there is a conflict between these two statements made by the same person, I might be wrong in my interpretation............

.
 

MisterFatty

Poppin Fresh!
Aug 1, 2008
698
33
38
I-I-I-I think that there is a conflict between these two statements made by the same person, I might be wrong in my interpretation............

.

Thats probably the Baffle them with bullshit part Booty spoke of...

As far as the "Bull with Fatty part" if the clown weren't trying to toot his own horn, and it was a review type thing instead of a piss poor attempt at shady marketing he would do much better...
 

Shockwave

Sr. Member
Sep 19, 2009
3,779
3,270
273
How does one emulate a tube anyway? Put an FET in a corona bottle? You make it sound like tubes are the only way to make good audio with swing but yet the Mauldulator doesn't contain a single tube. The common Cobra 148 GTL board is so much more suited for Hi-Fi AM modification then a typical HF amateur transceiver and yet we do it all the time on 75. The CB never has any crystal filters limiting the AM TX bandwidth like HF rigs do. The 148 uses series pass modulation so it doesn't have the low frequency limitations associated with a poor modulation transformer.

This means that the frequency response is entirely shaped by the capacitors used in coupling, bypassing, and any feedback loops if an IC audio amp is used. These feedback loops used on audio chips are often what rolls the high end off at 3 KHz. Going after all of those caps will easily provide more bandwidth then 80 to 6000 cycles. Of course you still need a good mic. I've modified the 148 board so that a signal generator set at one cycle would make the output meter bounce between zero and full scale once a second. The high end rolled off at 10 KHz. You need nothing more then a handful of capacitors.

Years ago the car audio market had popular 5 band 20 watt per channel automotive equalizer / amplifier units in metal cases. You want AM Hi-Fi the easy way? Buy one on eBay and wire a good XLR mic with a pre amp to drive the eq / amp and replace the entire AM TX audio chain with this external box! Might cost ya $30.00. This could introduce RFI problems if used with power. Just like connecting a PC to run a Mauldulator. That's why I like going after the caps in the existing audio chain that was designed to work in an RF environment.

Once you find VR-10 in the 148, getting well over 100% modulation peaks are no problem. In fact, the 148 board can readily be modified to produce 400% more AM peak power then stock. In 1985 I realized this board only used a modulated 6 volt line to feed the driver and final on AM. It didn't take a few days to figure out two different ways to get fully modulated 12 volts to them. Collector modulation trough a small transformer (out of a 29 LTD) or Heising right off the audio chip with a modulation reactor.

The Heising method is easier if you can find the right inductor. That's probably why it was copied in many CB books. The problem is the written Radio Shack DC alternator filter is not the right inductor. The part is very marginal in this application since it's inductance and core are not ideal. It can make some radios distort since it becomes difficult to keep the audio chip decoupled from the DC line with the Radio Shack part. Finding a modulation transformer and copying the schematic of the 29 LTD is probably easier now in terms of parts. You would still vary the DC carrier voltage through the transformer secondary.

Point is Wahlrite, if someone told you the only way to get 80 to 6000 cycles with swing was to buy a Mauldulator, they lied or were misinformed. I suspect you know this and are associated with the sales of this product. It's not possible to be "new on CB" as you claim with your new Mauldulator and have already grasped the concept of things like negative peak limiting in the terms you described. They don't print owners manuals that good anymore. Negative peak limiting is actually the only feature on your device that can't be easily "emulated" by just changing a few capacitors and proper carrier setting. Market this without the PC and you might have something.
 

Shockwave

Sr. Member
Sep 19, 2009
3,779
3,270
273
The more I think about this Mauldulator the more I question what you are doing with the PC? Don't tell me this entire thing is to just use the PC for basic audio processing? I need to hear something impressive like "The PC converts your audio signal into a Pulse Width Modulated signal that is then fed to our proprietary PWM final AF modulator stage". The website for this device is amazingly non descriptive concerning it's method of modulation but has wild claims. Unless this PC based AM modulator contains the basic PWM technology available in the simple HF kits available online, what is the requirement or advantage of PC based software? You could buy a nice little JoeMeek in a discrete metal box for excellent audio processing.
 

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