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

[Bob McGraw K4TAX]

We've made great technical strides in receivers.    Transmitters, well 
they are best described still as "out house" technology. Nothing has 
changed of significance in 25+ years.  In looking at my P3 and SSB 
signals on the bands, there are lots and lots of really bad signals.   
Yet I  most often hear "great signal" given as a report.

73

Bob, K4TAX

On 8/28/2019 3:50 PM, Wes wrote:
> 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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>>
>
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