[600MRG] XXM and XSV note

[Frank Lotito]

Or - another possibility for a signal containing 60*n Hz side bands instead of power supply hum - The circuits being used to generate the digitally coded audio tones and the 630 meter exciter signal may be the cause of the 60 Hz hum?  I'm sure we all remember the early days of computer generated digital modulated methods where the TX and RX audio lines going to and from the sound card a 1:1 isolation transformer was used to "break the ground loop."  (I believe that is still the case today.) Could the ground loop at the transmitting station be the culprit for some "transmitting" stations?  Can the "monitoring" station be part of the problem? - 
One more point - 60*n Hz hum or 120 *n Hz hum?  Would a full wave rectified DC power supply be characterized by 120*n Hz hum?  If so, that may be a clue - 

73 Frank Lotito K3DZ - pending WH2XHA

> From: dick.bingham at gmail.com
> Date: Mon, 27 Oct 2014 18:49:56 -0700
> To: ku4xrradio at gmail.com
> CC: 600MRG at w7ekb.com
> Subject: Re: [600MRG] XXM and XSV note
> 
> Greeting everyone
> 
> I, too, get the +\- n*60Hz decodes on some signals but only when the 'main' signal is in the plus dB range and the sideband levels are around SNR = -30 dB.
> 
> What this indicates to me is folks probably need to clean-up their power supplies to minimize the residual AC-ripple in their power supplies.
> 
> Dick/w7wkr and xsh-26 CN98pi
> 
> --------------------------------------------------------------------------------------------- 
> 
> 
> 
> > On Oct 27, 2014, at 5:54 PM, KU4XR <ku4xrradio at gmail.com> wrote:
> > 
> > Hi all:
> > 
> > Band is exceptionally quiet tonite, and signal are already quite strong..
> > Ken - XXM started out in positive numbers.. 2 stations I have yet to decode,
> > is XPQ, and XSV in Neils new QTH.. I have a problem that really nothing
> > can be done about.. I get the 60 Hz Up and Down decodes on XXM all the
> > time.. This starts in the early evening, and lasts until the wee hours of
> > the morning, and then disappears.. I have also seen multiple decodes
> > on XIQ several times, and even at 120 Hz from his mean frequency..
> > XJM has also shown the extra 60 Hz decode on occassions..
> > The thing that makes XXM's decodes " my problem " is that 60 Hz UP
> > from his mean frequency of 475.706, puts the extra decode at 475.766 KHz
> > which is right on top of where Neils signal is.. There is nothing that can
> > be done about the " WSPR Anomaly " which has happened to probably
> > about every receiver at some point.. Just wait it out, because it_Does_
> > go away..
> > An added observation here.. My cleaning of the ground connections
> > recently, has also quieted 630 meters noticably.. The biggest problem
> > as far as noise is concerned that I will now have to contend with, will
> > be the noisy powerlines as the WX starts getting colder.. Buzz, Buzz, Buzz
> > 
> > 73 all:
> > 
> > Andy - KU4XR
> > 
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