John,
I found the source of the 10.7 MHz spur. It's being generated inside the receiver itself. This is the first spur I have found that is not caused by switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the PCB surface. I get the strongest signal near the long trace between the two Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
Does the spur go away if the external reference is on (whether or not it is routed to the PLLs)?
73,
John KD6OZH
----- Original Message ----- From: "Juan Rivera" juan-rivera@sbcglobal.net To: "John B. Stephensen" kd6ozh@comcast.net Cc: eagle@amsat.org; "Bill Ress" bill@hsmicrowave.com; "Dave Black (Home)" dblack1054@yahoo.com; "Dave Black (Work)" dblack@mail.arc.nasa.gov; "Dave hartzell" hartzell@gmail.com; "David Smith" w6te@msn.com; "Don Ferguson" kd6ire@sbcglobal.net; "Juan. Rivera (Home)" juan-rivera@sbcglobal.net; "Juan.Rivera (Work)" Juan.Rivera@gd-ais.com; "Samsonoff@Mac. Com" samsonoff@mac.com Sent: Saturday, June 30, 2007 14:22 UTC Subject: 10.7 MHz Spur
John,
I found the source of the 10.7 MHz spur. It's being generated inside the receiver itself. This is the first spur I have found that is not caused by switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the PCB surface. I get the strongest signal near the long trace between the two Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
I don't know. I'll check...
Juan
-----Original Message----- From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, July 01, 2007 2:42 PM To: juan-rivera@sbcglobal.net Cc: eagle@amsat.org; Bill Ress; Dave Black (Home); Dave Black (Work); Dave hartzell; David Smith; Don Ferguson; Juan. Rivera (Home); Juan.Rivera (Work); Samsonoff@Mac. Com Subject: Re: 10.7 MHz Spur
Does the spur go away if the external reference is on (whether or not it is routed to the PLLs)?
73,
John KD6OZH
----- Original Message ----- From: "Juan Rivera" juan-rivera@sbcglobal.net To: "John B. Stephensen" kd6ozh@comcast.net Cc: eagle@amsat.org; "Bill Ress" bill@hsmicrowave.com; "Dave Black (Home)" dblack1054@yahoo.com; "Dave Black (Work)" dblack@mail.arc.nasa.gov; "Dave hartzell" hartzell@gmail.com; "David Smith" w6te@msn.com; "Don Ferguson" kd6ire@sbcglobal.net; "Juan. Rivera (Home)" juan-rivera@sbcglobal.net; "Juan.Rivera (Work)" Juan.Rivera@gd-ais.com; "Samsonoff@Mac. Com" samsonoff@mac.com Sent: Saturday, June 30, 2007 14:22 UTC Subject: 10.7 MHz Spur
John,
I found the source of the 10.7 MHz spur. It's being generated inside the receiver itself. This is the first spur I have found that is not caused by switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the PCB surface. I get the strongest signal near the long trace between the two Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
John,
The short answer is 'no'. Click here http://www.juanr.com/pages/hobbies/ham_radio/Eagle/IMD+Phase_Noise.htm for details and scroll to the bottom of the log...
Juan
-----Original Message----- From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, July 01, 2007 2:42 PM To: juan-rivera@sbcglobal.net Cc: eagle@amsat.org; Bill Ress; Dave Black (Home); Dave Black (Work); Dave hartzell; David Smith; Don Ferguson; Juan. Rivera (Home); Juan.Rivera (Work); Samsonoff@Mac. Com Subject: Re: 10.7 MHz Spur
Does the spur go away if the external reference is on (whether or not it is
routed to the PLLs)?
73,
John
KD6OZH
----- Original Message -----
From: "Juan Rivera" juan-rivera@sbcglobal.net
To: "John B. Stephensen" kd6ozh@comcast.net
Cc: eagle@amsat.org; "Bill Ress" bill@hsmicrowave.com; "Dave Black
(Home)" dblack1054@yahoo.com; "Dave Black (Work)"
dblack@mail.arc.nasa.gov; "Dave hartzell" hartzell@gmail.com; "David
Smith" w6te@msn.com; "Don Ferguson" kd6ire@sbcglobal.net; "Juan. Rivera
(Home)" juan-rivera@sbcglobal.net; "Juan.Rivera (Work)"
Juan.Rivera@gd-ais.com; "Samsonoff@Mac. Com" samsonoff@mac.com
Sent: Saturday, June 30, 2007 14:22 UTC
Subject: 10.7 MHz Spur
John,
I found the source of the 10.7 MHz spur. It's being generated inside the
receiver itself. This is the first spur I have found that is not caused
by
switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and
unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my
TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the
PCB
surface. I get the strongest signal near the long trace between the two
Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
The possible sources are the PLLs and the logic inside the onboard TCXO. Can you turn off the internal TCXO by removing the ferrite bead feeding it power and use and external 10 MHz reference?
If this doesn't work, the PLL division ratios can be changed.
73,
John KD6OZH ----- Original Message ----- From: Juan Rivera To: 'John B. Stephensen' Cc: eagle@amsat.org ; 'Bill Ress' ; 'Dave Black (Home)' ; 'Dave Black (Work)' ; 'Dave hartzell' ; 'David Smith' ; 'Don Ferguson' ; 'Juan.Rivera (Work)' ; 'Samsonoff@Mac. Com' Sent: Monday, July 02, 2007 03:19 UTC Subject: RE: 10.7 MHz Spur
John,
The short answer is 'no'. Click here for details and scroll to the bottom of the log...
Juan
-----Original Message----- From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, July 01, 2007 2:42 PM To: juan-rivera@sbcglobal.net Cc: eagle@amsat.org; Bill Ress; Dave Black (Home); Dave Black (Work); Dave hartzell; David Smith; Don Ferguson; Juan. Rivera (Home); Juan.Rivera (Work); Samsonoff@Mac. Com Subject: Re: 10.7 MHz Spur
Does the spur go away if the external reference is on (whether or not it is
routed to the PLLs)?
73,
John
KD6OZH
----- Original Message -----
From: "Juan Rivera" juan-rivera@sbcglobal.net
To: "John B. Stephensen" kd6ozh@comcast.net
Cc: eagle@amsat.org; "Bill Ress" bill@hsmicrowave.com; "Dave Black
(Home)" dblack1054@yahoo.com; "Dave Black (Work)"
dblack@mail.arc.nasa.gov; "Dave hartzell" hartzell@gmail.com; "David
Smith" w6te@msn.com; "Don Ferguson" kd6ire@sbcglobal.net; "Juan. Rivera
(Home)" juan-rivera@sbcglobal.net; "Juan.Rivera (Work)"
Juan.Rivera@gd-ais.com; "Samsonoff@Mac. Com" samsonoff@mac.com
Sent: Saturday, June 30, 2007 14:22 UTC
Subject: 10.7 MHz Spur
John,
I found the source of the 10.7 MHz spur. It's being generated inside the
receiver itself. This is the first spur I have found that is not caused
by
switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and
unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my
TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the
PCB
surface. I get the strongest signal near the long trace between the two
Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
John,
This is going to require some uninterrupted time when I can think. It's too difficult to get much done on work nights so I'll probably have to put it off until the weekend, or perhaps the 4th.
73, Juan
_____
From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, July 01, 2007 9:01 PM To: juan-rivera@sbcglobal.net Cc: eagle@amsat.org; 'Bill Ress'; 'Dave Black (Home)'; 'Dave Black (Work)'; 'Dave hartzell'; 'David Smith'; 'Don Ferguson'; 'Juan.Rivera (Work)'; 'Samsonoff@Mac. Com' Subject: Re: 10.7 MHz Spur
The possible sources are the PLLs and the logic inside the onboard TCXO. Can you turn off the internal TCXO by removing the ferrite bead feeding it power and use and external 10 MHz reference?
If this doesn't work, the PLL division ratios can be changed.
73,
John
KD6OZH
----- Original Message -----
From: Juan mailto:juan-rivera@sbcglobal.net Rivera
To: 'John B. mailto:kd6ozh@comcast.net Stephensen'
Cc: eagle@amsat.org ; 'Bill Ress' mailto:bill@hsmicrowave.com ; 'Dave mailto:dblack1054@yahoo.com Black (Home)' ; 'Dave Black (Work)' mailto:dblack@mail.arc.nasa.gov ; 'Dave hartzell' mailto:hartzell@gmail.com ; 'David Smith' mailto:w6te@msn.com ; 'Don Ferguson' mailto:kd6ire@sbcglobal.net ; 'Juan.Rivera mailto:Juan.Rivera@gd-ais.com (Work)' ; 'Samsonoff@Mac. mailto:'Samsonoff@Mac.%20Com' Com'
Sent: Monday, July 02, 2007 03:19 UTC
Subject: RE: 10.7 MHz Spur
John,
The short answer is 'no'. Click here http://www.juanr.com/pages/hobbies/ham_radio/Eagle/IMD+Phase_Noise.htm for details and scroll to the bottom of the log...
Juan
-----Original Message----- From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, July 01, 2007 2:42 PM To: juan-rivera@sbcglobal.net Cc: eagle@amsat.org; Bill Ress; Dave Black (Home); Dave Black (Work); Dave hartzell; David Smith; Don Ferguson; Juan. Rivera (Home); Juan.Rivera (Work); Samsonoff@Mac. Com Subject: Re: 10.7 MHz Spur
Does the spur go away if the external reference is on (whether or not it is
routed to the PLLs)?
73,
John
KD6OZH
----- Original Message -----
From: "Juan Rivera" juan-rivera@sbcglobal.net
To: "John B. Stephensen" kd6ozh@comcast.net
Cc: eagle@amsat.org; "Bill Ress" bill@hsmicrowave.com; "Dave Black
(Home)" dblack1054@yahoo.com; "Dave Black (Work)"
dblack@mail.arc.nasa.gov; "Dave hartzell" hartzell@gmail.com; "David
Smith" w6te@msn.com; "Don Ferguson" kd6ire@sbcglobal.net; "Juan. Rivera
(Home)" juan-rivera@sbcglobal.net; "Juan.Rivera (Work)"
Juan.Rivera@gd-ais.com; "Samsonoff@Mac. Com" samsonoff@mac.com
Sent: Saturday, June 30, 2007 14:22 UTC
Subject: 10.7 MHz Spur
John,
I found the source of the 10.7 MHz spur. It's being generated inside the
receiver itself. This is the first spur I have found that is not caused
by
switching power supplies.
The origin appears to be in the 10 MHz reference area. I turned off and
unplugged the SDR-IQ and fed the IF output from the 70 cm Receiver to my
TS-2000. The spur is still there.
Next I connected the RF input to my sniffer loop and moved it around the
PCB
surface. I get the strongest signal near the long trace between the two
Freq inputs to U4 and U9, the two phased-locked loops.
73,
Juan
participants (2)
-
John B. Stephensen -
Juan Rivera