[Elecraft] K3--Too much ALC creates energy on opposite sideband?

[Wes]

Barry,

With my SDR-IQ looking at the K3S i-f output I can see the other guy's 
signature.  I suppose a P3 does the same.  It's pretty amazing to see some of 
the lousy signals when we have such improved technology.

Wes

On 8/28/2019 1:30 PM, Barry wrote:
> Wes,
>     You make a very good point. The unwanted sideband will not be 0; there 
> will be some "residue" that can be heard if the signal is strong enough. And, 
> a lot has to do with the measurement method at the receiver.
>
>     Years ago, I was running DSBSC using a Globe DSB-100. I was told that my 
> carrier was way down but my unwanted sideband was only 20 db down. That was 
> interesting as I made no effort to suppress my unwanted sideband. The problem 
> was the method that was used to make the measurements and the strength of my 
> signal. So, determining the ratio of the two sidebands might be difficult, but 
> it may be the correct approach, However, it will require being able to "see" 
> both sidebands on an equal basis.
>
> 73,
> Barry
> K3NDM
>
> ------ Original Message ------
> From: "Wes" <wes_n7ws at triconet.org>
> To: elecraft at mailman.qth.net
> Sent: 8/28/2019 1:45:11 PM
> Subject: Re: [Elecraft] K3--Too much ALC creates energy on opposite sideband?
>
>> Although the manual doesn't say so, according to an ARRL review, the K3S is 
>> specified to have undesired sideband suppression of >50 dB.  ARRL claims an 
>> optimistic >70 dB.
>>
>> So if you are extremely strong at the other guy's place, he might easily hear 
>> an opposite sideband, even though your radio is operating correctly.  Ask him 
>> what the ratio is.
>>
>> Wes  N7WS
>>
>> On 8/28/2019 9:40 AM, Nate Bargmann wrote:
>>> I received a note this morning advising that I should check my ALC as he
>>> is seeing some energy on USB when I check into a 75m voice net on LSB.
>>> I am using an MC-50 microphone and am running the mic gain at 35 and the
>>> compression at 11.  My thinking was that generating opposite sideband
>>> energy would be quite difficult with the K3's DSP.  Am I wrong?
>>>
>>> I'll try working with him some morning and back down the mic gain a bit
>>> and see what that does for him.
>>>
>>> 73, Nate, N0NB
>>>
>>
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