[hpsdr] Mercury Spurious Emissions

[Terry Fox]

Or, could it be an image into a poor FM rig?  The difference between 144.39MHz and 122.88MHz is 21.51MHz.  Divide that by two, and you get 10.755MHz, 55kHz off the 10.7MHz IF of many VHF rigs.  Is that too far away, what if one of the other is off a little?
Terry, WB4JFI
 

From: Steve Hubbard 
Sent: Friday, September 09, 2011 8:41 PM
To: 'OpenHPSDR ' (open) 
Subject: Re: [hpsdr] Mercury Spurious Emissions

***** High Performance Software Defined Radio Discussion List *****




--------------------------------------------------------------------------------
The 47th harmonic of 3.072 MHz is 144.384 MHz, which is close to 144.39 MHz. 3.072 MHz is 122.88/40 and appears as CBCLK on the Mercury block diagram. If this signal has fast enough edges, this could be where your spurious is coming from. I don't have a Mercury myself so this is just speculation.

Steve VK5SH



On Sat Sep 10 9:22 , Jeremy McDermond sent:


  ***** High Performance Software Defined Radio Discussion List *****

  I've been "doing the rounds" of some of the local hamfests with my OpenHPSDR rig over the past couple of weeks and have run into a problem today. It seems as if Mercury is radiating spurious signals into the antenna connector. The symptom is showing up on 144.390 MHz. I have tried removing all boards from Atlas besides Mercury and pulling JP7 on the board to turn off the 10MHz clock. The signal is full-scale on an FM rig located near the receiver. When the antenna is removed from the BNC connector, the signal is much weaker, but a handheld near the box will still pick up the signal. Since it's happening with the 10MHz clock powered off, I'm assuming it has to be some issue with one of the clocks derived from the 122.88MHz clock. Not really sure where to start or whether folks have ideas on what could be the issue here.

  --
  Jeremy McDermond (NH6Z)
  Xenotropic Systems
  javascript:top.opencompose('mcdermj at xenotropic.com','','','')



  _______________________________________________
  HPSDR Discussion List
  To post msg: javascript:top.opencompose('hpsdr at openhpsdr.org','','','')
  Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
  HPSDR web page: http://openhpsdr.org
  Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/





--------------------------------------------------------------------------------
_______________________________________________
HPSDR Discussion List
To post msg: hpsdr at openhpsdr.org
Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
HPSDR web page: http://openhpsdr.org
Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20110909/c89b7770/attachment-0004.htm>