Date   

Re: Using SDR Console for RFI hunting: artifacts?

Dale Elshoff WB8CJW <dale.elshoff@...>
 



Virus-free. www.avast.com


Using SDR Console for RFI hunting: artifacts?

bill K7WXW
 

I am using SDR Console with an RSP2 to look for local noise sources, mostly in the 3 to 30 MHz range. I've seen/heard a couple of things that I don't understand and I am trying to figure out whether they are (a) real signals, (b) artifacts created by the software, (c) artifacts created by the radio.  If this isn't the appropriate forum, let know.

I have uploaded a couple of images that I will describe below. You can find them here:  

https://www.dropbox.com/sh/x6nff71a1iakg7y/AAALpTsfBvUqNXn3u3u0PClXa?dl=0

The first one: apparent FM broadcast station images in the HF band. I find an image of one or more commercial FM stations at several places in the HF band. The image, FM hump, shows one at 7.2 MHz. 

The second one: a repetitive, narrowband, signal.  The image, repetition, shows one example at 10MHz, of a signal that appears at approximately 18KHz intervals.  I have notice different repetition rates but the signal always spans whatever bandwidth I am examping. 

In both cases, I am running the RSP2 with the RF gain at 7, the IF gain at -55dB, and the AGC off.  

Here's the question:  Are these real signals or artifacts created by the radio or by the software and radio together? 

thx and 73 bill K7WXW


Re: waterfall spikes on 5 khz intervals

Joe Puma
 

Hey sounds reasonable, if you hear IMD yea maybe gain is up really high. Or you’re getting an overload of BCI but your commercial radio has some band pass filtering? Maybe put a BCI filter on and see if the spikes go away or if you hear am even at high gain. I get IMD on my rtfsdr’s with high RF gain in HF even when using the radios IF and the dongle as pan-adapter, I usually turn off any LNA or RF gain as it shouldn’t be needed for HF, as I was told.

Thanks,
Joe
kd2nfc

On Jan 23, 2019, at 1:01 PM, herbk@... wrote:

Hello, Joe:
Yes, I listened in on my transceiver (same antenna) and there is nothing there. There is no discernible spike/transmission/rfi when
approaching these frequencies. 

Listening more carefully, there is some audio (continuous) at extremely low levels throughout
the 75 meter band. When I move to another band and then back, it's not present. I would have
to assume that when the radio is first powered, the AGC may not be active and the radio maybe
without any attenuation. So it is at maximum sensitivity and this mus be intermodulation/overload. 
Changing bands must act as an AGC reset.
This would be consistent with my earlier screenshots: as you can see base signal levels drop 3 S-units after the
band switching has taken place.

That's my theory, anyway
Thanks

N2GEW <Screenshot_2019_01_23_123956.png>


Re: I've Been Busy

pinoleronica <pinoleronica@...>
 

When the “shutdown” end, I will commit to $ome dog food.

Rafael
NN3RP
Anan 7000 adept


Re: waterfall spikes on 5 khz intervals

HERB KEATON N2GEW
 

Hello, Joe:
Yes, I listened in on my transceiver (same antenna) and there is nothing there. There is no discernible spike/transmission/rfi when
approaching these frequencies. 

Listening more carefully, there is some audio (continuous) at extremely low levels throughout
the 75 meter band. When I move to another band and then back, it's not present. I would have
to assume that when the radio is first powered, the AGC may not be active and the radio maybe
without any attenuation. So it is at maximum sensitivity and this mus be intermodulation/overload. 
Changing bands must act as an AGC reset.
This would be consistent with my earlier screenshots: as you can see base signal levels drop 3 S-units after the
band switching has taken place.

That's my theory, anyway
Thanks

N2GEW


Re: waterfall spikes on 5 khz intervals

Joe Puma
 

I get this, if you have a HF radio tune to those frequencies, you might find that you can pick them up there too. I don’t know what makes them disappear on your setup but testing on a HF radio is a good way to see if that interference is in your neighborhood or just on your computer/sdr setup.  I suspect rfi from power transformers,  or something in your house.

 

Joe

Kd2nfc

 

 

Sent from Mail for Windows 10

 


From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> on behalf of herbk@... <herbk@...>
Sent: Wednesday, January 23, 2019 8:26:55 AM
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] waterfall spikes on 5 khz intervals
 
Good day all:
A phenomena I have wanted to ask about for sometime to see if anyone else notices this.
My circumstances are simple: Airspy HF+, SDR Console (Sept 11 2018 release), USB.

When I first open SDR Console and select the radio (last set to 75 meters in this case), I see the
waterfall displaying signal "spikes" at 5 khz intervals. They are not particularly strong,
but definitely visible in the waterfall on those intervals.

If I switch bands (memory 20 meters) and return to 75 meters via a memory location or
the history, the spikes are missing/gone. And they can be heard. If I stop the radio and re-start, the spikes are visible
again and can be "eliminated" by simply switching bands per previous.

Please see the attached screenshots: I could not find an explanation on this and wanted
to ask if this is unique to the HF+ starting up since I don't see this on another radio, the
RF Space Cloud IQ. Perhaps intermod ?

73
N2GEW


Re: I've Been Busy

David - G4PNX <david.painter@...>
 

I'm sure you have many more real than imaginary friends...just that you haven't met them yet.

More Poochy Pouches on the way.

David - G4PNX


Re: I've Been Busy

Simon Brown
 

Hah,

I've been working for myself since 1991, am now 61 years old and am not
going to work for anyone else again - ever!

Just me, the dog and my imaginary friends on the internet.

Simon Brown, G4ELI
www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of
Andrew OBrien
Sent: 23 January 2019 15:30
To: main@sdr-radio.groups.io
Subject: Re: [SDR-Radio] I've Been Busy

Flex should just sign Simon to a contract

Andy K3UK .


Re: I've Been Busy

Simon Brown
 

Thanks,

 

Just ordered more dog food 😊 .

 

Simon Brown, G4ELI
www.sdr-radio.com

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of wageners@...
Sent: 23 January 2019 14:58
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] I've Been Busy

 

Another donation made! 

Looking forward to your experiences with the Es’Hail 2. 

Stefan Wagener, VE4NSA


Re: I've Been Busy

Michael Durkin
 

 nah, $5 payment for every SDR used for Ham purpose ....

 how many million ham operators are there?

On Wed, Jan 23, 2019, 7:30 AM Andrew OBrien <k3ukandy@... wrote:
Flex should just sign Simon to a contract

Andy K3UK .




Re: waterfall spikes on 5 khz intervals

HERB KEATON N2GEW
 

Hello:
Yes, absolutely.
Going from AGC Low to AGC Off (Att 18 db) affects and removes many of these spikes.
Just as changing bands and returning to the previous does.

I am just curious what this tells me.
Perhaps I need to review the AGC settings and I will
figure this out.
Thanks very much.

N2GEW


Re: I've Been Busy

Andrew OBrien <k3ukandy@...>
 

Flex should just sign Simon to a contract

Andy K3UK .


Re: I've Been Busy

wageners@...
 

Another donation made! 

Looking forward to your experiences with the Es’Hail 2. 

Stefan Wagener, VE4NSA


Re: I've Been Busy

wageners@...
 

Very impressive and thanks so much for the satellite work!

It is much appreciated.

73, Stefan VE4NSA


Re: waterfall spikes on 5 khz intervals

Simon Brown
 

Hi,

 

Try different AGC settings?

 

Simon Brown, G4ELI
www.sdr-radio.com

 

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of herbk@...
Sent: 23 January 2019 13:27
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] waterfall spikes on 5 khz intervals

 

Good day all:
A phenomena I have wanted to ask about for sometime to see if anyone else notices this.
My circumstances are simple: Airspy HF+, SDR Console (Sept 11 2018 release), USB.

When I first open SDR Console and select the radio (last set to 75 meters in this case), I see the
waterfall displaying signal "spikes" at 5 khz intervals. They are not particularly strong,
but definitely visible in the waterfall on those intervals.

If I switch bands (memory 20 meters) and return to 75 meters via a memory location or
the history, the spikes are missing/gone. And they can be heard. If I stop the radio and re-start, the spikes are visible
again and can be "eliminated" by simply switching bands per previous.

Please see the attached screenshots: I could not find an explanation on this and wanted
to ask if this is unique to the HF+ starting up since I don't see this on another radio, the
RF Space Cloud IQ. Perhaps intermod ?

73
N2GEW


waterfall spikes on 5 khz intervals

HERB KEATON N2GEW
 

Good day all:
A phenomena I have wanted to ask about for sometime to see if anyone else notices this.
My circumstances are simple: Airspy HF+, SDR Console (Sept 11 2018 release), USB.

When I first open SDR Console and select the radio (last set to 75 meters in this case), I see the
waterfall displaying signal "spikes" at 5 khz intervals. They are not particularly strong,
but definitely visible in the waterfall on those intervals.

If I switch bands (memory 20 meters) and return to 75 meters via a memory location or
the history, the spikes are missing/gone. And they can be heard. If I stop the radio and re-start, the spikes are visible
again and can be "eliminated" by simply switching bands per previous.

Please see the attached screenshots: I could not find an explanation on this and wanted
to ask if this is unique to the HF+ starting up since I don't see this on another radio, the
RF Space Cloud IQ. Perhaps intermod ?

73
N2GEW


Re: I've Been Busy

davesc50@...
 

Hi Simon,

Great effort, another PayPal donation to follow shortly (after payday on Friday.....)

Keep up the good work.

Cheers,
Dave.S.



On 23/01/2019 07:38, Simon Brown wrote:

Hi All,

 

For the last two weeks I’ve been concentrating on the Lime: https://www.sdr-radio.com/Radios/LimeSDR and Pluto: https://www.sdr-radio.com/Radios/Pluto which I’ll soon be using with the Es’Hail 2 satellite.

 

A few fatal crashes have been found and fixed.

 

I’m working on the design of the FM Stereo / RDS Logging ready for the Summer 2019 season, we’ll be testing this Logging in two weeks or so in 3.0.5.

 

With any luck I’ll release 3.0.4 on Monday January 28th

 

My current list of 3.0.4 fixes:

 

  • ANAN code given a lot of attention, working much better.
  • Initial Lime transmit support.
  • Upgraded Airspy HF+ support library to latest release, CPU usage now much lower.
  • Fixed spectrum display in Auto mode when input signal is very low / zero.
  • Fixed crash adjusting the Span (bottom of display).
  • Redesigned the recording scheduler interface, simplified with no loss of functionality.
  • Satellite display now displays correct TX mode in the main window's ribbon bar tooltips.
  • Satellite display now uses fixed point fonts for name and times.
  • Satellite display - fixed fatal error selecting a world map which cannot be opened.
  • Satellite TLE data now has better sanity checking.
  • Downconverter supports frequencies up to 999.9 GHz.
  • Frequency display supports frequencies up to 999.9 GHz.
  • Fixed obscure bug in the Select Radio user interface.
  • Fixed SAM demodulation, PLL was not working fast enough.
  • More visibility/sanity checks when restoring a window position (example: Select Radio).
  • Added Pseudo Stereo (ribbon bar, Receive, Mode..., Pseudo Stereo).
  • Satellites, External Radio now supports both Rig 1 and Rig 2.
  • Fixed crash caused by a change in output device options such as enabling spatial sound.
  • Frequency database supports a Custom CSV layout.
  • Audio recording – a check is made that the folder exists before the recording is started.
  • bladeRF2 support now checks that the frequency is within the supported range.
  • New audio buffering logic (the way I maintain the buffer between demodulation and the playback / VAC device). This is simpler, cleaner and gives me a good base for the future. See the Playback Buffering page for options.
  • Reduced dangling connections on the server. Maybe not eliminated them all, but I’m not seeing any on my system (famous last words).
  • Airspy HF+ code now supports pre-production units properly, also units with old / original firmware.
  • If there are no receivers a warning is displayed.
  • More logic in coding where the program priority is raised when the system starts.
  • If the signal is muted due to input overload a warning icon is now shown in the status bar, previously just the Auto Mute text was shown. (This caught me out a couple of times).
  • Signal History - added Slower and Very slow.
  • ADALM-PLUTO receive support added.
  • ADALM-PLUTO transmit support added.

 

Simon Brown, G4ELI
www.sdr-radio.com

 

 


Re: I've Been Busy

f5nzz
 

hi all,


huge job Simon,

thanks for cumunity.


Very 73




F5NZZ Jean-Yves MONFORT
JN33AD LA GARDE 83  (VAR)
==============================================
Le 23/01/2019 à 08:38, Simon Brown a écrit :

Hi All,

 

For the last two weeks I’ve been concentrating on the Lime: https://www.sdr-radio.com/Radios/LimeSDR and Pluto: https://www.sdr-radio.com/Radios/Pluto which I’ll soon be using with the Es’Hail 2 satellite.

 

A few fatal crashes have been found and fixed.

 

I’m working on the design of the FM Stereo / RDS Logging ready for the Summer 2019 season, we’ll be testing this Logging in two weeks or so in 3.0.5.

 

With any luck I’ll release 3.0.4 on Monday January 28th

 

My current list of 3.0.4 fixes:

 

  • ANAN code given a lot of attention, working much better.
  • Initial Lime transmit support.
  • Upgraded Airspy HF+ support library to latest release, CPU usage now much lower.
  • Fixed spectrum display in Auto mode when input signal is very low / zero.
  • Fixed crash adjusting the Span (bottom of display).
  • Redesigned the recording scheduler interface, simplified with no loss of functionality.
  • Satellite display now displays correct TX mode in the main window's ribbon bar tooltips.
  • Satellite display now uses fixed point fonts for name and times.
  • Satellite display - fixed fatal error selecting a world map which cannot be opened.
  • Satellite TLE data now has better sanity checking.
  • Downconverter supports frequencies up to 999.9 GHz.
  • Frequency display supports frequencies up to 999.9 GHz.
  • Fixed obscure bug in the Select Radio user interface.
  • Fixed SAM demodulation, PLL was not working fast enough.
  • More visibility/sanity checks when restoring a window position (example: Select Radio).
  • Added Pseudo Stereo (ribbon bar, Receive, Mode..., Pseudo Stereo).
  • Satellites, External Radio now supports both Rig 1 and Rig 2.
  • Fixed crash caused by a change in output device options such as enabling spatial sound.
  • Frequency database supports a Custom CSV layout.
  • Audio recording – a check is made that the folder exists before the recording is started.
  • bladeRF2 support now checks that the frequency is within the supported range.
  • New audio buffering logic (the way I maintain the buffer between demodulation and the playback / VAC device). This is simpler, cleaner and gives me a good base for the future. See the Playback Buffering page for options.
  • Reduced dangling connections on the server. Maybe not eliminated them all, but I’m not seeing any on my system (famous last words).
  • Airspy HF+ code now supports pre-production units properly, also units with old / original firmware.
  • If there are no receivers a warning is displayed.
  • More logic in coding where the program priority is raised when the system starts.
  • If the signal is muted due to input overload a warning icon is now shown in the status bar, previously just the Auto Mute text was shown. (This caught me out a couple of times).
  • Signal History - added Slower and Very slow.
  • ADALM-PLUTO receive support added.
  • ADALM-PLUTO transmit support added.

 

Simon Brown, G4ELI
www.sdr-radio.com

 

 


Garanti sans virus. www.avast.com


Re: BladeRF 2.0 Enabling Bias-T

sagrpatl
 

Any updates on this? I'm also open to try implement it if you can lead me in the right direction. 


Re: I've Been Busy

Bob W8RMV
 

Perhaps us Flex Radio owners can start a "Go Fund Me" page for Simon, so he can fix & improve so many Flex issues.
Well done, Simon. 

-Bob W8RMV