[Elecraft] PX3 Problem

[Alan]

Hi Ted,

If they are spaced +/-60 Hz or +/- 120 Hz from the notch, then they are 
line-related noise getting on the I/Q signal.

73,

Alan N1AL


On 06/18/2015 08:21 AM, Dauer, Edward wrote:
> Thanks, Alan; that explains the notch perfectly.  My own version of the
> problem, however, is that the PX3 exhibits narrow S2+ spikes on either
> side of the notch.  Any ideas about that?  I have not seen it mentioned in
> the archives.
>
>
>
> Ted, KN1CBR
>
>
>>
>> Message: 3
>> Date: Wed, 17 Jun 2015 08:37:37 -0700
>> From: Alan <n1al at sonic.net>
>> To: elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] PX3 problem
>> Message-ID: <55819441.8050803 at sonic.net>
>> Content-Type: text/plain; charset=windows-1252; format=flowe
>
>> I think you must be referring to the notch that occurs at the KX3 VFO
>> frequency.  The I/Q output of the KX3 is AC-coupled so there is no
>> response at zero HZ, which corresponds to the KX3 VFO frequency.  In CW
>> mode, this is offset from the receive frequency by the CW pitch,
>> typically 600 Hz, either above or below the passband, depending on which
>> sideband is selected.
>>
>> If there is any 60 Hz or other line-related hum getting into the I/Q
>> input then you will see n*60 Hz sidebands on either side of the notch.
>>
>> Alan N1AL
>>
>>
>> On 06/16/2015 06:01 PM, John K7JLT wrote:
>>> I have not heard anything from Elecraft about this problem.
>>>
>>> John K7JLT
>>>
>>> "Dauer, Edward" <edauer at law.du.edu> wrote:
>>>
>>>> Just saw your posts in the archives.  I am experiencing the same,
>>>> except that in my case there are two narrow S2 spikes at either end of
>>>> the empty gap.  Has anyone at the factory ever commented or explained
>>>> what could be done?
>>>>
>>>> Ted, KN1CBR
>>> ______________________________________________________________
>>
>
>