Novice question re spurs
Novice question re spurs
I fired up the spectrum analysis software (latest version) on my RSP 2. I had some funny signals. In the course of tracking them down, I disconnected the antenna, and the signals persisted.
In the FM BCB band I get what look like FM signals at between -100 and -110 dBm.
More curious are 7 spurs between 250 and 375 MHz , all stronger than -90 dBm.
One spur, at 360 MHz, is at -58 dbm - even if I narrow sweep just to 359.99 to 360.01 MHz, with Ref level at -30 and range set to 100 dBm. It's an impulse-like filter, with nearby frequencies all at -120 dBm.
(A GIF screenshot is attached.)
Not what one expects with the antenna disconnected...
I tried some ferrites on the USB line, and they may have helped marginally, but spurs are still loud and clear.
Any ideas?
Tnx,
/Bill, K2PO
Portland, Oregon
In the FM BCB band I get what look like FM signals at between -100 and -110 dBm.
More curious are 7 spurs between 250 and 375 MHz , all stronger than -90 dBm.
One spur, at 360 MHz, is at -58 dbm - even if I narrow sweep just to 359.99 to 360.01 MHz, with Ref level at -30 and range set to 100 dBm. It's an impulse-like filter, with nearby frequencies all at -120 dBm.
(A GIF screenshot is attached.)
Not what one expects with the antenna disconnected...
I tried some ferrites on the USB line, and they may have helped marginally, but spurs are still loud and clear.
Any ideas?
Tnx,
/Bill, K2PO
Portland, Oregon
- Attachments
-
- 360 MHz spur, no ant.gif (136.6 KiB) Viewed 38318 times
Last edited by bconwell on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason
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Re: Novice question re spurs
'Should have read
...It's an impulse-like signal...
attached is another screenshot - a 500 MHz sweep, again with no antenna connected.
/Bill, K2PO
...It's an impulse-like signal...
attached is another screenshot - a 500 MHz sweep, again with no antenna connected.
/Bill, K2PO
- Attachments
-
- 500 MHz sweep, no antenna.GIF (150.17 KiB) Viewed 38317 times
Last edited by bconwell on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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Reason: No reason
Re: Novice question re spurs
Do others see similar spectra with no antenna connected? Or is my device unique in this behavior?
/Bill, K2PO
/Bill, K2PO
Last edited by bconwell on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason
Reason: No reason