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MikesRadioRepair Reviews Asymod iii HiFi Board

Yeti Communications Ltd said:
no not in the ssb tx path ..after the double sideband suppressed carrier leaves the balance modulator chip it goes to the IF path via the main filter depending on what mode its on (ssb) to remove the unwanted sideband product then on to the mixers and out to the driver ..no switched transistor between the B/L and the first filter in that chassis the audio and carrier mixing happens at the B/L.
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Ohh sorry I was talking about the audio path. BEFORE the balanced modulator that sends the audio from the mic to the balanced modulator or the ta7222 audio amp for AM. On the audio path the transistor is after the balanced modulator, sorry for the confusion!
 
Yeti Communications Ltd said:
making your own 10.695mhz filters is not hard...look at that page and look at the bitex kit the hams use..for construction of multi pole filters ...select 2 pole filters and cascade to your liking ..all about the slope bro ...get your learn on but really 4khz on ssb is ok ..any wider and the ham bones will be jelly and your cber neighbours will be angry lol

of course guessing with out a sweep gen will lead to roads of ruin
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With the progress that SDR has made I will continue my path of not hand building filters....lol
 
yes really the best way to go ..when they make a dongle that does 10mhz without a convertor i would look at sdr via the I.F of a cb radio (have not looked for a while as heading the mcHF sdr way soon as my next project )
 
Yeti Communications Ltd said:
yes really the best way to go ..when they make a dongle that does 10mhz without a convertor i would look at sdr via the I.F of a cb radio (have not looked for a while as heading the mcHF sdr way soon as my next project )
Click to expand...
You can mod some of the dongles for direct sampling that cover under 10mhz. Most CB's use a first IF of 7.8khz and would need a buffer amp so the addition of the dongle didnt load down the IF. I tied a dongle into the first IF of my TS-850 (73.05mhz) without issue, works really well!
 
JoeDirt said:
OK Robb believe the guy who copied all his technical information direct from MMM. These board or any CB/expot will not transmit ESSB. Not saying that it isnt possible but im not sure you can even buy the wide filters.

You can bypass some caps and direct inject the balanced modulator but all that might give you a slightly flatter frequency response it will not transmit ESSB.

I repeat NONE of his radios transmit ESSB.

One exception: I hear the Stryker exports do transmit slightly wider than a normal CB/export from the factory.
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I don't think he stole MMM designed; I think he re-engineered it and did some different things to it. However, not gonna buy it to find out what - lol.
 
Robb said:
I don't think he stole MMM designed; I think he re-engineered it and did some different things to it. However, not gonna buy it to find out what - lol.
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He really didn't engineer anything new. He added some already existing dc-dc buck boost scheme (available separately on eBay for .99¢) so you can run single voltage and some blinking lights.
 
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JoeDirt said:
You can mod some of the dongles for direct sampling that cover under 10mhz. Most CB's use a first IF of 7.8khz and would need a buffer amp so the addition of the dongle didnt load down the IF. I tied a dongle into the first IF of my TS-850 (73.05mhz) without issue, works really well!
Click to expand...
Do you have a schematic of the MMM board?
Would like to look at it.
 
if someone wanted to market to the guys who want to run "hifi style" on AM using CB radios, then i would think the product to sell as a kit would be a simple AM modulator circuit that accepts a line level input.
just one switch on the radio that goes to a relay inside to switch from the mic input to the external AM modulator.

I run my madison like this and i LOVE the way it sounds.
I do not like to run anything digital in the chain, so mine goes, mic to mixer (with compression) to AM modulator in radio.

im actually surprised i don't see more people doing it this way.
LC
 
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loosecannon said:
if someone wanted to market to the guys who want to run "hifi style" on AM using CB radios, then i would think the product to sell as a kit would be a simple AM modulator circuit that accepts a line level input.
just one switch on the radio that goes to a relay inside to switch from the mic input to the external AM modulator.

I run my madison like this and i LOVE the way it sounds.
I do not like to run anything digital in the chain, so mine goes, mic to mixer (with compression) to AM modulator in radio.

im actually surprised i don't see more people doing it this way.
LC
Click to expand...
If you had external audio from rack gear why would you use the stock mic with the radio?
 
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loosecannon said:
if someone wanted to market to the guys who want to run "hifi style" on AM using CB radios, then i would think the product to sell as a kit would be a simple AM modulator circuit that accepts a line level input.
just one switch on the radio that goes to a relay inside to switch from the mic input to the external AM modulator.

I run my madison like this and i LOVE the way it sounds.
I do not like to run anything digital in the chain, so mine goes, mic to mixer (with compression) to AM modulator in radio.

im actually surprised i don't see more people doing it this way.
LC
Click to expand...
Would this mod board "in theory" add an AM regulator and AN612 balance modulator to a Cobra 29 basically leaving the old modulation transformer for rx duty and nothing more?

JoeDirt said:
If you had external audio from rack gear why would you use the stock mic with the radio?
Click to expand...
For emergency situations where a mobile hand mic is far more practical than rack gear, or to use a factory ssb audio chain?

Robb said:
Do you have a schematic of the MMM board?
Would like to look at it.
Click to expand...
A PDF is out there that gives a good rundown of what happened, MMM and another guy sat down and reversed an asymod board to compare it to the 1st gen MMM board, they are n̶e̶a̶r̶l̶y̶ identical. A schematic is handrawn on page 18 in the file. (The old version that requires negative supply voltages)
 
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