Elecraft

Re: PX3 problem

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John Hendricks-2

Re: PX3 problem

I have not heard anything from Elecraft about this problem.

John K7JLT

"Dauer, Edward" <[hidden email]> 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
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Alan Bloom

Re: PX3 problem

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" <[hidden email]> 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
> ______________________________________________________________

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Edward A. Dauer

PX3 Problem

In reply to this post by John Hendricks-2

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 <[hidden email]>
>To: [hidden email]
>Subject: Re: [Elecraft] PX3 problem
>Message-ID: <[hidden email]>
>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" <[hidden email]> 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
>> ______________________________________________________________
>

Alan Bloom

Re: PX3 Problem

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 <[hidden email]>
>> To: [hidden email]
>> Subject: Re: [Elecraft] PX3 problem
>> Message-ID: <[hidden email]>
>> 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" <[hidden email]> 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
>>> ______________________________________________________________
>>
>
>