Reconnect the switcher on the receiver PCB and see what shows up.
 
To eliminate the noise, we may have to connect the PCB to the CAN-Do widget with a ribbon cable and place it at the other end of the module case. If the internal switcher also pollutes the VCO control voltage, it could be moved to a separate PCB.
 
73,
 
John
KD6OZH
----- Original Message -----
From: Juan Rivera
To: [email protected] ; 'John B. Stephensen' ; 'Robert McGwier'
Cc: [email protected] ; 'David Smith' ; 'Dave Black (Work)' ; 'Dave Black (Home)' ; 'Samsonoff@Mac. Com' ; 'Juan.Rivera (Work)'
Sent: Sunday, June 10, 2007 02:47 UTC
Subject: RE: [eagle] Re: New 70 cm Receiver Test Results

 

Folks,

 

I am quitting for the evening.  I just posted more data on my web (at 1945 Pacific time).  You can jump there by clicking here, or go to the AMSAT 70 cm receiver page and click on Spur Troubleshooting under Project Status.

 

I was able to remove power from the Can-do module and power the receiver from external power supplies.  All of the spurs disappeared when the 13 volts was removed from the module.  Tomorrow I’ll start reconnecting the receiver internal power supply sections and see how far I can get before spurs reappear.  I do not believe all the noise is coming from the Can-do module.  Tomorrow I’ll find out for sure…

 

73,

 

Juan

WA6HTP