Very scratched and clipped modulation on USB and LSB

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dk6hpc
 

Posts: 1
Joined: 04 May 2022, 08:13

Very scratched and clipped modulation on USB and LSB

Post by dk6hpc »

Hello , my rig has a bad modulation , scratched and clipped on SSB after build up. Also the same with ext.microphone from Baofeng. Is it possible , to fix the problem over the menue ? Same others here, who have /or had the same problem? It sounds like a overdrived amplifier microphone and i have some dropouts while speaking, maybe the modulation would be limitet . Also no mod if i hold the mic more than 10 cm from the mouth , the ext. mic the same case.

TNX

73 Peter
Murphyv310
 

Posts: 52
Joined: 18 Apr 2022, 19:33

Re: Very scratched and clipped modulation on USB and LSB

Post by Murphyv310 »

Hi
How are you testing the modulation? One problem that is unavoidable is the hash from these sets on transmit that distorts the perceived signal when you use a radio nearby to listen. I have a Trio TS830S that I use for near field reception. No antenna connected and the tr usdx has a dummy load, it sounds very good. As soon as I put any form of antenna into the Trio, even a screwdriver blade it sounds terrible. You can try transmission into your antenna and monitor it with an online SDR, I use Kiwi SDR and find it very useful.
Regards, Trevor. MM0KJJ
kg9h
 

Posts: 3
Joined: 29 Apr 2022, 01:52

Re: Very scratched and clipped modulation on USB and LSB

Post by kg9h »

Same here, internal or external mic, no difference. Icom 7300 or Drake R-4B, no difference. I have the latest F/W installed. CW is perfect.
kg9h
 

Posts: 3
Joined: 29 Apr 2022, 01:52

Re: Very scratched and clipped modulation on USB and LSB

Post by kg9h »

Looking at my board layouts, I see Q1, Q2, Q3, but on the solder side I see nothing in Q4, Q5
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AC9YY
 

Posts: 133
Joined: 21 Mar 2022, 00:04
Location: Illinois, USA

Re: Very scratched and clipped modulation on USB and LSB

Post by AC9YY »

With Q1-3 you don't populate Q4 or Q5, they are for alternative PA FETs.
AC9UV
 

Posts: 8
Joined: 19 May 2022, 22:09

Re: Very scratched and clipped modulation on USB and LSB

Post by AC9UV »

Just finished yesterday building the kit. The audio monitored by my IC-7300 is terrible. I was next to the radio and connected to a long wire. Talking close to the mic got more sound. Moving away from the mic and it became hit and miss audio. I checked the wiring of the mic for the ground side and it appears to be correct. BTW what is the effect on the audio if you connect the mic backwards? What do you experience?

I have ordered some external mic's to see if I can improve on that. But if there is a problem on the board that won't help.

Are there setting that would effect the audio. I see the TX pwr suggested. Anyone test that?

Thanks

---John AC9UV
K6ARK
 

Posts: 3
Joined: 27 May 2022, 13:34

Re: Very scratched and clipped modulation on USB and LSB

Post by K6ARK »

Tweaking Noise Gate and TX Drive settings can help a little, but the reality is that the audio quality is not great with these rigs. It's usable with the right settings, but we can't expect commercial SSB rig audio quality from something like this. Changing the mic element is unlikely to help. DL2MAN can likely provide a better explanation, but I believe the tx audio quality is limited by the simple design of the system and processing power of the controller.

Adam
K6ARK
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Leon
 

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Joined: 25 May 2022, 08:41
Location: Barcelona
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Re: Very scratched and clipped modulation on USB and LSB

Post by Leon »

I have tried many settings. It is not that audio is bad, it is almost impossible to understand what’s being said. What worked best for me is tx setting 3 and speaking very very close from the mic. It is like no modulation or saturation. Nothing in between
It is saturated or nothing… i have tried several electrect mics with same poor results
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