KX3 audio distorted with AGC on, fine with AGC off

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KX3 audio distorted with AGC on, fine with AGC off

Juhani Ahvenainen
The firmware version in my KX3 is MCU 02.33, DSP 01.33. The AGC (menu) parameters are at their default values. If you turn off AGC (menu AGC MD) the audio is fine. If you turn AGC on the audio is very clearly distorted on signals stronger than about S7. The stronger the signal the worse the distortion.

Using different sets of headphones or PC speakers of good quality makes no difference. I have tried tweaking the AGC parameters (AGC*THR especially) and I have backed up and restored the configuration with the utility PC program. Switching between 14 V and 12 V power supplies seems to make no difference. What else can you do? Unfortunately, this issue takes the joy out of using the otherwise great radio.

73, Juhani OH5YU
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Re: KX3 audio distorted with AGC on, fine with AGC off

dmb@lightstream.net
Juhani,

I've encountered this as well. It's particularly noticeable with some of
the wide ESSB sig's which tend to use less compression and no doubt have a
higher peak to average ratio than most other signals on the band.

I've found that reducing the RF gain control to about -10 to -12, helps
quite a bit. For me, the granularity of the AF gain is too coarse.
Sometimes, even a setting of "1" is too much when I'm wearing headphones
(depending upon the particular phones). For that reason, I reduced the RF
gain, and in so doing discovered the side benefit that itsignificantly
reduced or eliminated the distortion you mention.

73,
Dale
WA8SRA


> The firmware version in my KX3 is MCU 02.33, DSP 01.33. The AGC (menu)
> parameters are at their default values. If you turn off AGC (menu AGC MD)
> the audio is fine. If you turn AGC on the audio is very clearly distorted
> on signals stronger than about S7. The stronger the signal the worse the
> distortion.
>
> Using different sets of headphones or PC speakers of good quality makes no
> difference. I have tried tweaking the AGC parameters (AGC*THR especially)
> and I have backed up and restored the configuration with the utility PC
> program. Switching between 14 V and 12 V power supplies seems to make no
> difference. What else can you do? Unfortunately, this issue takes the joy
> out of using the otherwise great radio.
>
> 73, Juhani OH5YU


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