http://elecraft.85.s1.nabble.com/K3-Odd-ALC-behavior-tp7633052p7633133.html
Wes, I understand that... assuming you are responding to me... I was asking
sensitive. I'm taking about the KIO3B USB CODEC here... Max NG7M
> Except when the sound card is in the computer instead of the radio, "Line
> In" is receiving signal from the program via the sound card 'speaker'
> output, not the microphone. Moving the card into the radio doesn't change
> this. The only thing changed is it's too darned sensitive.
>
> Regards,
>
> Wes N7WS
>
>
> On 8/5/2017 9:39 AM, Joe Subich, W4TV wrote:
>
>>
>> On 8/5/2017 11:14 AM, Wes Stewart wrote:
>>
>>> But IMHO, you need to put a 30 dB attenuator on the input of the
>>> internal sound card; it is way too sensitive. I'm having to run the Windows
>>> gain at less than 5% and Line In at 10 or less.
>>>
>>
>> Actually, you need to adjust the options in the Windows *.inf file
>> used for the PCM-series CODEC (or use the codec that identifies as
>> line level). Windows is turning on a 20 dB preamp in the CODEC.
>>
>> I suspect if one sets the Windows Sound Options (Control Panel) to
>> display dB rather than percentage, the minimum level will be some-
>> thing like 16 to 20 dB! That indicated the fixed 20 dB "mic preamp"
>> is engaged.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 8/5/2017 11:14 AM, Wes Stewart wrote:
>>
>>> Wayne,
>>>
>>> There are no beat notes. These frequencies, at least from the FT8
>>> program in Tune mode are single frequency. Based upon output RF spectrum
>>> measurements*, with for example 1010 Hz input and 4-5 bars of ALC, I see
>>> spurious or intermodulation sidebands, down -65 dBc. If I change nothing
>>> else but adjust the tone frequency to 1000 Hz the spectrum is the same but
>>> the ALC bars are cyclic, going from none to 4-5, at about the 2 HZ rate
>>> Brian reported earlier. (Slow ALC in action?) That's the good news.
>>>
>>> If I set the tone to 1500 Hz, the FT8 mid-band target, I'm presented
>>> with the cyclic ALC and some ~193 Hz, -50 dBc sidebands.
>>>
>>> I have tried this with both the K3S internal sound card and via Line
>>> In/Out into my laptop sound card. The results are more-or-less the same.
>>> But IMHO, you need to put a 30 dB attenuator on the input of the internal
>>> sound card; it is way too sensitive. I'm having to run the Windows gain at
>>> less than 5% and Line In at 10 or less.
>>>
>>> I would suggest that you do some measurements with a low-distortion sine
>>> wave audio source run into the radio to eliminate the possibility that this
>>> junk is a result of all of the digitally generated tones.
>>>
>>> If this (what I will call a) problem continues to exist then I think a
>>> fix is in order. Expecting users to select particular frequencies to use
>>> to set gain levels isn't an acceptable workaround.
>>>
>>> Regards,
>>>
>>> Wes N7WS
>>>
>>>
>>> * My "spectrum analyzer" is my SDR-IQ which I have used to measure TX
>>> IMD on both my K3 and K3S. Your IMD
>>> measurements on my K3S concurred with mine within 1 dB or less.
>>>
>>> On 8/4/2017 4:45 PM, Wayne Burdick wrote:
>>>
>>>> Is it possible that a beat note between tones (and their harmonics) is
>>>> what’s modulating the ALC reading? If so, moving the tone slightly off the
>>>> standard pitch may be an acceptable workaround.
>>>>
>>>> Wayne
>>>> N6KR
>>>>
>>>>
>>>> On Aug 4, 2017, at 1:42 PM, Wes Stewart<
[hidden email]> wrote:
>>>>>
>>>>> Good find Brian!!! I see it too in FT8.
>>>>>
>>>>> This probably explains the great variability in results reported. Some
>>>>> of us have a problem, others say, Huh, what the heck are you talking about?
>>>>>
>>>>> Wes, N7WS
>>>>>
>>>>>
>>>>> On 8/4/2017 11:33 AM, Brian Hunt wrote:
>>>>>
>>>>>> Here's some followup:
>>>>>> FLDIGI shows the "pumping" affect with carrier tones of 500, 1000,
>>>>>> 1500, and 2000 Hz.
>>>>>> WSJT-X 1.8 shows the "pumping" affect with carrier tones of 1000,
>>>>>> 1500 and 2000 Hz (couldn't select 500 Hz).
>>>>>>
>>>>>> The affect is very narrow with frequency. 10 Hz either way and the
>>>>>> output and ALC display and MON output is rock solid. Changing the K3
>>>>>> filter center frequency has no effect on the above.
>>>>>>
>>>>>> 73,
>>>>>> Brian, K0DTJ
>>>>>>
>>>>>> On 8/4/2017 10:58, Brian Hunt wrote:
>>>>>>
>>>>>>> I spent some quality time with my K3, FLDIGI and an oscilloscope
>>>>>>> today. I had the same problem as described. Looking at my USB soundcard
>>>>>>> output to the K3, the amplitude of the audio from FLDIGI in TUNE mode was
>>>>>>> rock solid. Looking at the MON output from the K3, the level oscillated in
>>>>>>> time with the ALC "pumping" at about 2.4 Hz (timed with a stop watch). At
>>>>>>> the same time the K3 power output into a dummy load was rock solid at a
>>>>>>> selected 10 watts.
>>>>>>>
>>>>>>> Then I changed the carrier frequency in FLDIGI slightly off 1500 Hz
>>>>>>> and the "pumping" went away! At 1515 Hz I could easily set the ALC to the
>>>>>>> desired 4 bars solid, 5th flickering. Then I remembered (and verified)
>>>>>>> that the default filter center in DATA A mode is 1500 Hz. I changed the
>>>>>>> filter center frequency to 1450 Hz and moved the FLDIGI frequency around
>>>>>>> but couldn't reproduce the "pumping".
>>>>>>>
>>>>>>> I plan to repeat the same tests with WSJT-X 1.8 but wanted to get
>>>>>>> this out to the group.
>>>>>>>
>>>>>>> 73,
>>>>>>> Brian, K0DTJ
>>>>>>>
>>>>>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>>> Help:
http://mailman.qth.net/mmfaq.htm>>> Post: mailto:
[hidden email]
>>>
>>> This list hosted by:
http://www.qsl.net>>> Please help support this email list:
http://www.qsl.net/donate.html>>> Message delivered to
[hidden email]
>>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>> Help:
http://mailman.qth.net/mmfaq.htm>> Post: mailto:
[hidden email]
>>
>> This list hosted by:
http://www.qsl.net>> Please help support this email list:
http://www.qsl.net/donate.html>> Message delivered to
[hidden email]
>>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home:
http://mailman.qth.net/mailman/listinfo/elecraft> Help:
http://mailman.qth.net/mmfaq.htm> Post: mailto:
[hidden email]
>
> This list hosted by:
http://www.qsl.net> Please help support this email list:
http://www.qsl.net/donate.html> Message delivered to
[hidden email]
>
M. George