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#qmx #Heil #SSB #QMXplus #qmx #Heil #ssb #QMXplus

 

I plugged my Heil Pro 7 (IC) with AD-1-IC into my QMX+ with version 1_01_003 Firmware. I adjusted the mic gain with the hardware test from my PC and later from the QMX. I made my first contact with a POTA station in Houston from Colorado on 20m, with difficulty because of my weak signal. Although I have tried, I have yet to make any additional contacts on 20m.
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I plugged the Ad-1 stereo earphone connector directly into the QMX, but had to use a stereo splitter to isolate the ring and ground connections. While the ICOM radios like the 7610 supplies an 8 volt bias and the QMX 3.3 volt bias, the Pro 7 IC seems to work OK with the QMX. I use VOX.
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Using a Li-ion battery to power the QMX, I plan to drive over to a ham buddy who knows my voice and make further audio adjustments and check the transmitted signal quality. ?I will post my settings here after doing so.
 

Update:
The stereo splitter was for the mic/PTT connector and to plug the Pro 7 mono mic connector into.
 

I hadn't thought of using a headset...I have a BM10ic that would probably work pretty well so I shall collect bits for an appropriate adaptor!
 

Hi,
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I'm using a gaming headset with build in mic. I found that the mic wasn't sensitive enough as I had to set the mic gain on my QMX so high that it started to produce undesirable background noise.
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So, decided to use an inexpensive mic preamp module, MAX9814. The module has a mic capsule soldered on the board. I removed the capsule and wired it up to my headset mic and wired in a foot switch for PTT for hands free operation.
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Mel. M0KMD.
 

Mel, was the gaming headset mic an electret element, or another type like dynamic or crystal elememt? What does its resistance measure?

Gaming headsets are known to be poor quality in general. In my mobile IC-7100, I used a headset with mic but from a well known reputable company and with an electret mic. It worked great for the 7100.
 

The headset has a electret mic. I didn't measure the resistance. It sounded perfectly adequate when I used it on my pc.
Hower, the output from the mic seems too low using it with my QMX+.
I did try two other electret capsules I had in my junk box, they were marginal improvement over the headset mic.
The headset works great with the mic preamp, however.?
The mic gain is set to 35 and compression set to 3, produces good results on my QMX.
 

Very good Mel!

I think a mic preamp perhaps on a daughter board with special consideration to low noise components, good equalization, layout and filters, and a low impedance output to feed the QMX A/D converter would be an excellent addition to the QMX. Depending on the dynamic range of the A/D converter and a higher input signal, one might not need the spur removal with the internal mic and second A/D converter.
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I have some small mic preamp boards, and designed a discrete one for a dynamic mic I had. I will ?have to give it a try if the Pro 7 doesn¡¯t work well.
 

I just used an inexpensive MAX9814 Arduino mic amplifier module, which I also happen to have in my junk box.
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Cheers.
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Mel. M0KMD.
 

I did not go mobile, but rather made a recording of the audio on my ICOM transceiver. These were my final settings after trying various settings on my QMX with the Heil Pro 7 (IC)headset. I worked a couple of POTA stations who said my audio was clear, just weak. I left some heading words out but I think you will get the idea. Hope this is helpful.
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EQ
?On
?Global -17
?300
?+2
?.5
?3000
?0
?.9
?
AGC
?On
?10
?10
?2
?
RX filter
?2500
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TX filter
?2700
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Mic gain
?63
Comp
?3
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Noise Red
?On
?
Noise Gate
?On
?Thresh 50
?99
?Att 10
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Vox
?On
?Thresh 35
?Hold 6
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Drive 900
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CESSB On
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Phase PD On
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