An interesting link, Simon.

If only there was a similar kit covering VLF, LF, MW, SW.

BUT…it would have to tune in step with the SDR using Console.

 

Tom G6PZZ

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Simon Brown
Sent: 23 April 2021 10:46
To: SDR-Radio@groups.io
Subject: [SDR-Radio] Low-cost, software-definable front end preselector for SDRs

 

ATEK1001

 

An open source, low-cost, software-definable front end preselector for SDRs and wideband receivers.

 

ATEK1001 | Crowd Supply

 

7 fixed-frequency, 1 external bypass, switchable

• Band 1: 485-810 MHz
• Band 2: 660-1125 MHz
• Band 3: 960-1610 MHz
• Band 4: 1420-2435 MHz
• Band 5: 2070-3685 MHz
• Band 6: 3245-5395 MHz
• Band 7: 4660-7730 MHz

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

--

- + - + -

Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.

ATEK1001

An open source, low-cost, software-definable front end preselector for SDRs and wideband receivers.

ATEK1001 | Crowd Supply

7 fixed-frequency, 1 external bypass, switchable

• Band 1: 485-810 MHz
• Band 2: 660-1125 MHz
• Band 3: 960-1610 MHz
• Band 4: 1420-2435 MHz
• Band 5: 2070-3685 MHz
• Band 6: 3245-5395 MHz
• Band 7: 4660-7730 MHz

Simon Brown, G4ELI

https://www.sdr-radio.com

--

Update, it does eventually work but takes approximately 2 minutes to launch. Version is 3.027

Dave,

There's no screenshots or information on where you are seeing what you describe so apologies if I am not talking the same thing you are.

In order to calculate an azimuth and elevation as you describe above, you need two points.  One of those is your latitude and longitude and elevation.

The other is the satellite position, the point on the earth that the satellite is directly overhead of at any given time, along with it's elevation.

From those two items, you can calculate an azimuth an elevation.

So I believe the answer is, the 'satellite position' expressed as a lat lon is the point on the ground of which the satellite is directly overhead.

If you're talking about fixed geostationary satellites like TV that talk about a 54 degree East or 54 degree west slot, those are Geostationary satellites and reference their longitude above ground, their latitude is 0 degrees (above the equator).  Their orbit allows them to appear to remain in the exact same spot.

Ryan, NF0T

On Thu, Apr 22, 2021 at 1:17 PM David Coles <g7gzc@...> wrote:

Please explain “satellite position”.

 

As a walker I can calculate a compass bearing, aka azimuth.

 

This is with reference to grid North.

 

This is then adjusted to magnetic North.

 

The result is expressed in degrees to a maximum of 360.

 

However, a satellite position might be given as 54° W, for example.

 

Sorry, I just don't get it!

 

Where is it?

 

I'm okay with elevation.

 

For information, my location is Latitude 51.445265 and Longtitude -0.345086

 

Locator JO01EK16

 

Many thanks Dave G7GZC

 

 

For those who are interested, reading the couple of links provided below will give a better idea of what is going on, nothing to do with demodulation or rtlsdr dongles or suchlike things.   As for over the air signals, a number of AM broadcast signals do have stable carriers, even to within 0.1Hz.  Try Data Analyser and find out, though, yes, a decent SDR with a stable clock, likely disciplined by GPS, is needed to do the original recording.  Variations in the amplitude or frequency of the received signal can indicate propagation disturbances....that is the purpose of the exercise.

But, back to the original question...

73

Nick


At 01:59 2021-04-22, jdow wrote:

OK - I was just wondering. Post processing I can see forcing the data to provide that level of bandwidth, at least in theory. I am not at all sure you can ask most SDRs or post processors to provide data in a precise 1Hz bandwidth. And even if it is one bin of the FFT (with a power of two sampling clock) that's not a precise 1 Hz noise bandwidth, I don't believe. Are you looking to record the noise in a 1 Hz bandwidth or are you looking for signal plus noise with a signal that varies level (but not frequency?) The former seems possible with a correction factor. You may have to provide the factor by calibrating the system. The detection mode will make some difference on the readout. Is it a peak or average detector? Is it a true RMS detector? (I^2+Q^2 related.) Is it a rectifier and peak or average detector? All these have something to say for them. I prefer the true RMS approach. But then you have post filtering on the data which can upset calibration, particularly if signal plus noise is involved.  I don't know that Simon has released enough information to perform the analysis to get an analytical solution here. I remember some old HP Journal articles (yes, HP old) addressing this. Even the filter shapes will tweak your measurement of noise. I always worked with known equipment and settings to create known Eb/N0 values. Fortunately I never had to work backwards and calculate Eb/N0 for a really weak signal in noise. That is a thoroughly fugly calculation with just a whole lot of things that can get in the way of accuracy. That is why I believe I'd calibrate the system myself. And do be aware that you can specify to 1 Hz but, for example, your rtlsdr dongle will never be guaranteed to be accurate to that frequency within 7 Hz plus any clock error present. The synthesizers involved have their own step size which is NOT 1 Hz. That may be the source of another person's problems here; but, the description is not clear enough to know. As a side issue, where do you get a signal that is stable enough to be seen in the noise of this kind of setup? Over the air signals vary considerably with small variances in pressure, temperature, and humidity even on ground wave paths. Through the ionosphere I suspect it might not be possible depending on the length of observation and the behavior of the Sun. {O_O}

On 20210421 18:28:44, Nick Hall-Patch wrote:

SDRConsole's Data Analyser (in View / Options) does indeed make that claim, resolution bandwidth to better than 0.01Hz under the right settings, when playing back previously recorded SDR files.  More samples are used to generate finer scaled FFTs than are used in most SDR playback software.  See https://dk8ok.org/2021/01/22/magnificient-fdm-s3-the-millihertz-magnifier/ for example. There is a possibility of generating CSV files of signal strength versus time for a passband of 1Hz (but only 1Hz) in Data Analyser....hence my question, because other software, such as Carrier Sleuth ( https://www.blackcatsystems.com/software/medium_wave_carrier_display_app.html ) can generate CSV files for narrower bandwidths yet, but is very clear that it is displaying the highest value signal strength within that bandwidth, unless you are asking for a single bin worth of bandwidth.  But peak value that can be a different, and lower, value from the total power within a passband. 73 Nick At 23:57 2021-04-21, jdow wrote:

Um, er, ah, 1 Hz bandwidth? I am not sure SDRRadio will do that in any meaningful sense. You are pushing the limits of what a tool designed for picking olives when you try to use it to pick grapes. You may have to design your own instrument if you want that level of instrumentation accuracy. Depending on the front end the measurements you would get would be whimsical at best. {o.o} On 20210421 09:32:57, Nick Hall-Patch wrote:

This may be more a forum question, but isn't a bug report, more a "how is the sausage being made" question. When I have created a CSV file in Data Analyser, it has taken its information from a +/- 0.5Hz slice of spectrum. For each timestamp, is that data the total power level within the +/-0.5Hz bandwidth, or the maximum power level? Thank you. Nick

Nick Hall-Patch Victoria, BC Canada

Nick Hall-Patch
Victoria, BC
Canada

OK - I was just wondering. Post processing I can see forcing the data to provide that level of bandwidth, at least in theory. I am not at all sure you can ask most SDRs or post processors to provide data in a precise 1Hz bandwidth. And even if it is one bin of the FFT (with a power of two sampling clock) that's not a precise 1 Hz noise bandwidth, I don't believe. Are you looking to record the noise in a 1 Hz bandwidth or are you looking for signal plus noise with a signal that varies level (but not frequency?) The former seems possible with a correction factor. You may have to provide the factor by calibrating the system. The detection mode will make some difference on the readout. Is it a peak or average detector? Is it a true RMS detector? (I^2+Q^2 related.) Is it a rectifier and peak or average detector? All these have something to say for them. I prefer the true RMS approach. But then you have post filtering on the data which can upset calibration, particularly if signal plus noise is involved.  I don't know that Simon has released enough information to perform the analysis to get an analytical solution here. I remember some old HP Journal articles (yes, HP old) addressing this. Even the filter shapes will tweak your measurement of noise. I always worked with known equipment and settings to create known Eb/N0 values. Fortunately I never had to work backwards and calculate Eb/N0 for a really weak signal in noise. That is a thoroughly fugly calculation with just a whole lot of things that can get in the way of accuracy. That is why I believe I'd calibrate the system myself. And do be aware that you can specify to 1 Hz but, for example, your rtlsdr dongle will never be guaranteed to be accurate to that frequency within 7 Hz plus any clock error present. The synthesizers involved have their own step size which is NOT 1 Hz. That may be the source of another person's problems here; but, the description is not clear enough to know. As a side issue, where do you get a signal that is stable enough to be seen in the noise of this kind of setup? Over the air signals vary considerably with small variances in pressure, temperature, and humidity even on ground wave paths. Through the ionosphere I suspect it might not be possible depending on the length of observation and the behavior of the Sun. {O_O}

On 20210421 18:28:44, Nick Hall-Patch wrote:

SDRConsole's Data Analyser (in View / Options) does indeed make that claim, resolution bandwidth to better than 0.01Hz under the right settings, when playing back previously recorded SDR files.  More samples are used to generate finer scaled FFTs than are used in most SDR playback software.  See https://dk8ok.org/2021/01/22/magnificient-fdm-s3-the-millihertz-magnifier/ for example. There is a possibility of generating CSV files of signal strength versus time for a passband of 1Hz (but only 1Hz) in Data Analyser....hence my question, because other software, such as Carrier Sleuth ( https://www.blackcatsystems.com/software/medium_wave_carrier_display_app.html ) can generate CSV files for narrower bandwidths yet, but is very clear that it is displaying the highest value signal strength within that bandwidth, unless you are asking for a single bin worth of bandwidth.  But peak value that can be a different, and lower, value from the total power within a passband. 73 Nick At 23:57 2021-04-21, jdow wrote:

Um, er, ah, 1 Hz bandwidth? I am not sure SDRRadio will do that in any meaningful sense. You are pushing the limits of what a tool designed for picking olives when you try to use it to pick grapes. You may have to design your own instrument if you want that level of instrumentation accuracy. Depending on the front end the measurements you would get would be whimsical at best. {o.o} On 20210421 09:32:57, Nick Hall-Patch wrote:

This may be more a forum question, but isn't a bug report, more a "how is the sausage being made" question. When I have created a CSV file in Data Analyser, it has taken its information from a +/- 0.5Hz slice of spectrum. For each timestamp, is that data the total power level within the +/-0.5Hz bandwidth, or the maximum power level? Thank you. Nick

Nick Hall-Patch Victoria, BC Canada

Nick Hall-Patch
Victoria, BC
Canada

SDRConsole's Data Analyser (in View / Options) does indeed make that claim, resolution bandwidth to better than 0.01Hz under the right settings, when playing back previously recorded SDR files.  More samples are used to generate finer scaled FFTs than are used in most SDR playback software.  See https://dk8ok.org/2021/01/22/magnificient-fdm-s3-the-millihertz-magnifier/ for example.

There is a possibility of generating CSV files of signal strength versus time for a passband of 1Hz (but only 1Hz) in Data Analyser....hence my question, because other software, such as Carrier Sleuth ( https://www.blackcatsystems.com/software/medium_wave_carrier_display_app.html ) can generate CSV files for narrower bandwidths yet, but is very clear that it is displaying the highest value signal strength within that bandwidth, unless you are asking for a single bin worth of bandwidth.  But peak value that can be a different, and lower, value from the total power within a passband.

73

Nick


At 23:57 2021-04-21, jdow wrote:

Um, er, ah, 1 Hz bandwidth? I am not sure SDRRadio will do that in any meaningful sense. You are pushing the limits of what a tool designed for picking olives when you try to use it to pick grapes. You may have to design your own instrument if you want that level of instrumentation accuracy. Depending on the front end the measurements you would get would be whimsical at best. {o.o}
On 20210421 09:32:57, Nick Hall-Patch wrote:

This may be more a forum question, but isn't a bug report, more a "how is the sausage being made" question. When I have created a CSV file in Data Analyser, it has taken its information from a +/- 0.5Hz slice of spectrum. For each timestamp, is that data the total power level within the +/-0.5Hz bandwidth, or the maximum power level? Thank you. Nick

Nick Hall-Patch
Victoria, BC
Canada

Hello jdow,
I don't really understand why you jump in any discussion, sometimes without a clue about what is the topic.
Do you have an R2? if yes tune a carrier, change the frequency, click on center (the pop-up control panel which appears over the panadapter zone) and please confirm the carrier has moved.
I have reported it as a bug few weeks ago, it has noting to do with GS locking (yes, my R2 is GPS locked) or with moon Doppler.

----------------------
73 de Max, N5NHJ (I8NHJ)

Wednesday, April 21, 2021, 11:51:57 PM, you wrote:

Phase lock it to GPS and the unscheduled wandering frequency should end. But, the Moon moves relative to your location so you get frequency shift there, I am sure you know. {o.o} On 20210421 08:45:39, Max Mucci, N5NHJ via groups.io wrote: Re: [SDR-Radio] AirSpy R2 Setup with SDRC V3

Hello Frank,
I've been using the R2 for 70 cm EME with excellent results (the only issue I have found using it with SDRC is the frequency shift after centering the signal in the panadapter).
You want to play a bit with the Radio panel controls, what I've found working quite well for me in terms of sensitivity and SNR is:
Gain: Sensitive/17
LNA: 17
Mixer: 20
VGA: 19
Visual: -30

----------------------
73 de Max, N5NHJ (I8NHJ)

Wednesday, April 21, 2021, 10:00:49 AM, you wrote:

I am doing a TransAtlantic 144Mhz VHF Signal project this summer and plan to use the AirSpy R2 OR an SDRPlay RSP2 as the Receiver monitoring Eu FT8 VHF beacons. I have used both of these before but it has been a couple of years .  The SDRPlay RSP2 appears to be working and the noise floor is approximately -120dBm on 6M.  (VHF antennas not erected yet).  A weak test signal is being received. The Airspy doesn't seem to be working.  The noise floor is -95dbFS and no test signal can be heard.  What can be the issue?.   If I run the Airspy using SDR# I can't hear anything.  I am not familiar with SDR# so I must have not installed it correctly.  Is there a procedure to setup the Airspy to work in SDRC V3? Frank VO1HP

Um, er, ah, 1 Hz bandwidth? I am not sure SDRRadio will do that in any meaningful sense. You are pushing the limits of what a tool designed for picking olives when you try to use it to pick grapes. You may have to design your own instrument if you want that level of instrumentation accuracy. Depending on the front end the measurements you would get would be whimsical at best. {o.o}
On 20210421 09:32:57, Nick Hall-Patch wrote:

This may be more a forum question, but isn't a bug report, more a "how is the sausage being made" question. When I have created a CSV file in Data Analyser, it has taken its information from a +/- 0.5Hz slice of spectrum. For each timestamp, is that data the total power level within the +/-0.5Hz bandwidth, or the maximum power level? Thank you. Nick

Nick Hall-Patch
Victoria, BC
Canada

Max
Thanks for your reply.   I have looked everywhere in SDRC V3 but see no Radio control panel when using AirSpy R2?...Can you send me a screen shot of what you are seeing

Frank VO1HP

This may be more a forum question, but isn't a bug report, more a "how is the sausage being made" question.

When I have created a CSV file in Data Analyser, it has taken its information from a +/- 0.5Hz slice of spectrum.

For each timestamp, is that data the total power level within the +/-0.5Hz bandwidth, or the maximum power level?

Thank you.

Nick