Galaxy DX959 Hi-Fi Mod

[Deleted User 30222]

I have finished this hi-fi mod i have been working on. But for some reason it doesn't seem to be working. This is what i followed.

1. Drill and mount the mono jack and switch on the back of the radio
2. locate and remove C235.
3. Solder the + leg of the 10uf cap to the + hole of C235.
4. Solder a wire from - leg of the 10uf cap to the center pin of the on/on switch.
5. Solder a wire from one side of the switch to the - hole of C235.
6. Solder a wire from other side of switch to + of the mono jack.
7. Solder a wire from - side of mono jack to board ground (You can solder it to a can).

So the radio works fine in normal mode. But when i switch to hi-fi mode, i get nothing. I don't hear myself with the Talk Back on. I do hear the radio click when i key it up. So i'm guessing the keyer works fine. That is just a push button switch with pin 1(shield) and pin 3(tx) connected.

Also, my DX959 goes to a Behringer mixer. Any help would be greatly appreciated

[nosaj]

Can you please link a schematic for your radio and where you obtain the info for the hifi mod?
nosaj
N1EBC

[Deleted User 30222]

This is where you can see the schematic. [Please login or register to view this link]
The mod i got from a Facebook group.

[295 antenna]

Ok maybe i dont understand? Is the problem when in Hifimode you cant here your self through your talkback .? Question have you tried to see if you have any modulation through another radio ?

[Deleted User 30222]

Duh, never thought of trying it with another radio. And when my radio is set in the "mod" setting, the needle on the meter doesn't move.

[Deleted User 30222]

Alright, tried it with another radio. My other radio is picking it up. I just can't hear anything.

[Blue Ox2]

This is an answer from the Hi-Fi group and Richard Orlick - Cut pin one on IC 4 and jumper trace to stock mic jack, increase C 235 171 and 149, 2uf is good for frequencies below 100 Hz. This is good for AM and SSB and no need to add any additional jacks...

Don't know if you saw this, or not.
Hope it works out for you.

[Blue Ox2]

This is another document from the files section on the Hi-Fi page -

Ok good afternoon everybody. I just wanted to go ahead and do this write up because I get asked all the times about the different ways you can modify your radios to get that "HiFi" sound. So I figured that I would go ahead and do a write-up for everyone explaining the different ways you can achieve that sound. The two main ways that you can go about getting that sound or number one, Direct Injection, or number two, using an asymmetrical modulator, for example a Mauldulator or an Asymod. You can also go thru the front Mic jack, use Audio processing equiptment and a studio Mic but youre still going to have all the radios audio bandwidth limiting components holding back the audio and you're gonna sound better, yes, but youre gonna sound like and EQ'd d104 and you're not gonna get that sound that You hear on the band that separates that one radio from the rest because you dont have transmit bandwidth anymore than from 300hz-3000khz. No lows, and not highs. All mid range to make the best communications quailty audio. I see guys that use Ipads and Irigs going right into the front of the radio and its just a waste. You know that fat wide sound when you hear it out in DX and it stands out from the rest? You must bypass or modify the stock transmit audio section to get that. And why try to reinvent the wheel? Guys have been acheiving hi fideltity amplitude modulation for 50 years. This is nothing new. Do the research, get the knowledge. Its all out there for you to find. So now I'm going to explain the different ways that I mentioned.
Direct injection is injecting processed audio(studio mic, mixer, eq etc) directly into the AM modulator of the radio bypassing all the audio bandwidth limiters in the radio so basically you can transmit higher highs and lower lows and get that wide fat sound. With straight direct injection and No other modifications, you cant get much more than 100% modulation(100% positive peaks) without starting to distort because you are going over 100% on the negative peaks. Some peoples voices have natural assymetry and can acheive positive peaks over 100% naturally. You can also lower the radios carrier to get more positive peak head room and get over 100% positive. Adding a Negative Peak Limiting circuit will limit yor negative peaks to around 95-99% and gives you a fail safe against modulating to far into the negative. I like to run my stuff at 100% positive average modulation with large peaks upwards of 120-125%. Keeping as close to the 1:4 carrier to peak power ratio is wise because 1:4 is perfectly linear and has the least amount of distortion. Remember, assymetry is a form of distortion. A mic by itself will not give enough "output" to modulate the radio. The minimum equipment required after the modification is some sort of microphone preamp and a microphone to get the levels high enough to modulate the radio. This is the way I choose to run. Direct injection with the LeadFoot Labs mods work the best for me.
Now the Asymmetrical modulator, IE the Mauldulator or the Asymod. What they do are enable you to get upwards of 300% modulation(300% positive) and keep your negatives at or below 100% and give you the ability to adjust your positive and negative Peaks, or in other words, adjust the asymmetry of your carrier envelope. So it doesn't distort and splatter and you will get the RMS swing you're used to seeing. An asymmetrical modulator directly drives the finals of your radio and you adjust the radios carrier, your audio gain, and your asymmetry directly from the Standalone asymmetrical modulator unit. I ran direct injection for 2 years, then went ahead and built Mauldulator. I like the modulator, but it wasn't for me, so I went back to direct injection. But the Mauldulator is a great unit and I'm not taking any thing away from it. Its an all in one unit that makes it easy to get over 100% positive without pinching the negative peaks with minimal modifications to the radio.
Just doing these modifications, will not give you that "HiFi Sound". The way you sound is up to how you process your audio. This just gives you the capability to transmit at the wider frequency bandwidth needed to get full AM fidelity. It is up to you to process and taylor your audio to how you want it to sound. It does not create a sound, it just gives you the ability to bring outboard audio processing in and not be limited on bandwidth except if you are going through the mic jack.
Now there are other methods I see guys use like those I-Rigs and such, but they go right into the mic jack and go thru the stock audio chain. Doing that,
Guys if you want to do some research on processing, check out [Please login or register to view this link] or [Please login or register to view this link]. Also there is a links file in the Files section of the group i want everyone to go look at and check them all out. Join groups like AMFone, but dont post about 11m stuff in there. Just go there to learn and read. Get your learn on! This was just a quick little write up, and I'm sure I forgot some things or left some things out, so if my admins or anyone else has anything to add please go ahead and add it but I just wanted to go ahead and put this information out there for everyone and I am going to go ahead and put this information in the file section of the group so it's there forever.
Thanks LeadFoot In The Stone (From the Hi-Fidelity Radio closed Facebook group published 06/04/2019)

[MDYoungblood]

First thing is how you are keying the radio, just use the radio's mic as the PTT switch, the audio portion is disconnected when the radio is in HiFi mod.
Next check how you have the audio leads ran, one from the installed jack in the radio to the output of the Behringer mixer, make sure it is the right output channel. Next from the Behringer mixer to the microphone you are using for the HiFi, make sure it's the right input. You can check the Behringer mixer is right by plugging it into a speaker or headphones, I would do this first to check the sound quality before hooking it up to the radio.
Last hook it up and with the mic gain on the radio at max and the gain on the mixer at min, try the setup again. If it is working make your adjustments for best audio output again.

3's

Greg

[Deleted User 30222]

This is an answer from the Hi-Fi group and Richard Orlick - Cut pin one on IC 4 and jumper trace to stock mic jack, increase C 235 171 and 149, 2uf is good for frequencies below 100 Hz. This is good for AM and SSB and no need to add any additional jacks...

Don't know if you saw this, or not.
Hope it works out for you.

Not sure what hes talking about. There is no IC 4 on a DX959

[MDYoungblood]

increase C 235 171 and 149, 2uf is good for frequencies below 100 Hz

Wow, guess my dogs will enjoy listening to the radio, only they can hear that low of a frequency.

3's

Greg

[Blue Ox2]

k, well that's how much I know about all that.

Going to start listing some slightly
used equipment soon.

73 fer now,

Mike

[Deleted User 30222]

Well i finally got it up and running. Turns out i wasn't turning the Main Mix high enough. Thanks for everybody's help.

[Deleted User 30222]

Well i thought i had it working. Did get some speakers plugged in. First problem is i have to put my mouth right up to the mic, then cup my hands around my mouth and the mic and talk loud. Modulation on the mixer seems ok, but not getting much if any sound on the radio end. Now i am going by my radios meter, with it set to Mod. Plus i can't hear myself on my other radio. Any suggestions

[Deleted User 30222]

Ok maybe i dont understand? Is the problem when in Hifimode you cant here your self through your talkback .? Question have you tried to see if you have any modulation through another radio ?

With the talk back turned all the way up i can barely hear myself. Have tried turning the mic gain up and down with no results. And if i whistle or talk load enough i can see the needle on the radio move up and down.

[Blue Ox2]

maybe the radio needs more power. I run the RM KL 503 with mine to get anywhere.

JMO

73,

Qj^

[Deleted User 30222]

maybe the radio needs more power. I run the RM KL 503 with mine to get anywhere.

JMO

73,

Qj^

Have you tried it with out the 503? What happens then. I guess i can try.

[Deleted User 30222]

Ok, tried it with the amp on. Doesn't seem to be any difference.

[Deleted User 30222]

Made some adjustments on the mixer side, and it all looks good now.

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