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Finn posisjonen til masten som ditt 4G / LTE modem er koplet til med Celle ID! (4G / LTE Cell ID database with position info., Norway)

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Lurer du på hvor masten som ditt 4G / LTE modem er koplet til er lokalisert? (LTE Cell ID database with locations, Norway). 

Maybe this can help: I found a comprehensive database that contains approx 147000 lines at https://opencellid.org/ This dataset is made publicly available by Opencellid for download.

Here is the cell id data I downloaded for Norway:

 242.csv

Rename the file to 242.csv (it has a txt extension) and open it or import it in Excel.

You can then find lat and long position from the Excel cheet

Then enter that lat / long (with decimals and add E and N after the numbers) into the search field of Google maps

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How to adjust your parabolic antenna for QO-100 / Es’Hail amateur radio geostationary satellite

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VIDEO. How to adjust your dish for QO-100 geostationary satellite:

  • Find Astra 28,2 degrees (strong signals in Northern Europe and Central Europe) with a low cost satfinder with sound / analog meter
  • This is one of the most eastern TV satellites that are very strong, so you can start east and move towards south until you find the first strong satellite on your satfinder (you should find Astra 28,2)
  • Now move a slight bit more to the south until you are out of the strong Ku band lobe of the Astra 28,2
  • You should point in the correct direction (elevation is the same in practice)
  • If you have a generic LNB the IF should be on 739,7 MHz. Your SDR should be able to tune to that QRG

Join our FB group (exclusively for licenced radio amateurs by the respective government administrations) https://www.facebook.com/groups/252645695661305/members/

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Quatar Oscar 100 Geostationary Satellite / QO-100, Es’Hailsat, new Facebook Group for licensed radio amateurs

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There is a new Facebook group for Quatar Oscar 100 Geostationary Satellite. (QO-100, Es’Hailsat). Licensed radio amateurs are welcome to join via the link below! (Exclusively for licenced radio amateurs by the respective government administrations).
Members typically discuss equipment, design of equipment, antenna designs, post QSO videos and sound recordings etc.   https://www.facebook.com/groups/252645695661305/

cover photo, No photo description available.

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Securing your node-red editor and dashboard on the Raspberry Pi

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If you leave your node-red installation on your rpi running without a password you will be hacked and soon owned by people using your rpi as a bit coin mining device. It is easy to set a password for the editor and for the dashboard!:

Node-red is installed in /home/pi/.node-red (the . dot in front means you will normally not be able to see the directory as the dot means it is hidden. Therefore, set up your file manager to show hidden files. Alternatively, if you are using the terminal you can use ls -a or ls -al in the /home/pi directory to see all that is there).

Edit the settings.js file with

nano settings.js

Uncomment this section in the settings.js file:

adminAuth: {
type: "credentials",
users: [{
username: "admin",
password:"xxxhash key is pasted herexxxx",
permissions: "*"
}]
},

You will need to generate a hash with node-red-admin and type the hash-pw command. The hash key you paste above in the field xxxhash key is pasted herexxxx (keep the ” ” signs and dont mess up the [ ] {} , stuff).

You will probably have to install the node-red-admin tools (google how to do that with npm) to be able to use node-red-admin

For the dashboard you do the same procedure but you now un-comment this line

httpNodeAuth: {user:"user",pass:"xxxxdashboard hash key is pasted herexxxx"},

Make sure to keep all commas etc!
If you are uncertain to what directory your rpi reads the settings.js file from, you can start the node-red with node-red-pi and look at the messages in the console. It will report the location and file it uses. Dont edit the wrong settings.js file … there are several installed on your pi it seems

Restart the node red
IMPORTANT! CLEAR THE CACHE of your web browser. If not you will not see the password on the editor and the dashboard, as node-red uses cache quite heavily. See https://support.mozilla.org/en-US/kb/how-clear-firefox-cache for how to clear Firefox cache

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How to check for a NAN (Not A Number) in C++ in embedded systems without exception handlers

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Sometimes there are bugs or special corner conditions that makes a NAN (Not A Number) occur in code compiled from a C++ source and executed on an embedded systems without memory to run exception handlers.

Here is what @Jalf writes over at StackExchange:

According to the IEEE standard, NaN values have the odd property that comparisons involving them are always false. That is, for a float f, f != f will be true only if f is NaN.

Note that, as some comments below have pointed out, not all compilers respect this when optimizing code.

For any compiler which claims to use IEEE floating point, this trick should work.