[Elecraft] Will the K2 noise blanker help with this QRM?

[Owen B. Mehegan]

That's what I was afraid of. I spent some time the other night looking  
into DSP filtering that I could do on my PC, but I realized after  
awhile that once the S9+20 signal has gone through the K2 and deafened  
it, filtering it out of the audio is a bit pointless - I'm still going  
to be missing all the weaker signals.

If anyone wants to look at and comment on the intermittent horrible  
40m QRM I get, here are some visual and audio samples:

http://nerdnetworks.org/stuff/40m_waterfall.png
http://nerdnetworks.org/stuff/40m_qrm.png
http://nerdnetworks.org/stuff/40m_qrm.mp3

This stuff manifests as an S9 or greater buzz/hash that slowly creeps  
up and down in frequency. 40 will be nicely usable and relatively  
quiet, and then this stuff starts up and I might as well just shut off  
the radio (or try 80, which is at least sometimes usable even with the  
previous QRM I asked about). I suspect that if a constant-frequency  
QRM like the stuff on 80 can't be filtered easily, this varying stuff  
can't be either.

I have heard about the MFJ and Timewave noise canceling gizmos, I can  
imagine one of those working OK on the TV noise, but I would assume  
that this stuff that moves around wouldn't be so easy to deal with.

My friend told me that I need to use a "move to a cabin in the woods"  
filter.

--
owen at nerdnetworks.org (Owen B. Mehegan)
'Something is rotten in the state of Denmark.'
   --William Shakespeare

On Dec 24, 2010, at 4:01 AM, Jim Wiley wrote:

>
>
> Oh good grief.  3.579 (approx) MHz is the color burst frequency, and  
> pretty much any standard NTSC color TV set (vacuum tube or solid  
> state) has a crystal oscillator that runs on that frequency.  The  
> horizontal  sweep oscillator is on about 15 kHz, and the vertical  
> sweep oscillator runs at slightly less than 60 Hz.  This same 3.579  
> MHz  oscillator is the reason for the persistent weak signal on  
> 14.312 or 14.313 (the 4th harmonic of 3.579) that plagues many of us.
>
>
> Also, many devices use this same 3.579 (more or less) frequency to  
> control some internal function or process - crystal controlled  
> clocks,  fax machines,  microwave oven timers, and video games   
> being only few examples.  TV sets are locked to a particular  
> frequency by the transmission they receive, whereas other devices  
> are not.  This is the reason you can often hear many many individual  
> signals around these frequencies - particularly on 20 meters.
>
>
> I am not too sure about more modern HDTV receivers.  Hopefully they  
> use a different mechanism,. so perhaps we will see a gradual  
> lessening of this problem as time passes. Or not.
>
>
> - Jim,  KL7CC
>
>
>
> Monty Shultes wrote:
>>
>> 3580 is a magic frequency, actually 3979.xx is the vertical  
>> (horizontal?) oscillator frequency in OLD tube TV sets.  I've been  
>> listening to that buzz for decades.
>> Best Holiday Wishes to all -   Monty  K2DLJ
>>
>> O That said, I'm
>>
>>> seeing some noise on 80m that is always present at night, on 3580  
>>> khz
>>> and other places.
>>>
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