Category Archives: SDR


Capturing NOAA Satellite Imagery With RTL-SDR

Capturing NOAA Satellite Imagery With RTL-SDR

NOAA Satellite

NOAA Satellite Imagery

In this entry I’ll show you how to grab NOAA Satellite Imagery.  There are still 3 operational satellites.  NOAA 15, 18, and 19.  NOAA 15 started acting up last October but is still functional.  The pic just to the left is from NOAA 15.

Did you know that ANYONE with the right hardware can download telemetry from these satellites?

Not only that, it can be done pretty cheaply.   All it takes is a computer, an antenna, a USB RTL-SDR device, and some free computer software.

It isn’t that difficult either but does take some time to get it working correctly.

And for the purposes of the blog, I am doing this on a Linux (Ubuntu) laptop.  But you can do it on Windows as well.
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Building A Linux Computer For Offline Use

Building A Linux Computer For Offline Use

Linux Computer

HP 15.6″ FHD 15-ef2030tg for a Linux Computer

I talk a lot about having a computer set up for off grid situations.   But let’s build our own Linux computer that we can use both online and especially offline.  I’ll try to teach you some valuable tips along the way.

Yeah, yeah, yeah, the picture next to this shows Windows.  That’s a stock photo of the laptop I’m using for this project.   The HP 15.6″ FHD 15-ef2030tg.

I picked this up for a song and it was so cheap, I believe, because this is a model from 2021 that is probably the last of its stock.  It has decent specs though and this thing is IDEAL for a Linux computer.
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Using A Computer With No Internet Connection

Using A Computer With No Internet Connection

What if you woke up and there was no internet connection?

No Wifi Area Sign 2315098 Vector Art at VecteezyI have written similar blogs a couple of times in the past but like to keep it up to date as technology cruises forward or if I discover new hardware.  Just what would you do if you woke up and there was no internet connection?  This could be due to a massive telecom hack, or natural disaster, or an act of war.

Surprisingly, your computer can do quite a lot without a network connection, even if you can’t picture in your mind how that could be.  Let’s explore how we can use a computer with no internet connection.

What Can We Do With No Internet Connection?

Quite a bit actually.  Let me make a quick list:

  • GPS
  • Radio (AM, FM, shortwave, weather, air band, etc.)
  • Television
  • Monitor Emergency Communications (Police, Fire, EMS, Military, etc.)
  • Establish Emergency Communications between computer using Long Range Radio  (LoRa)
  • Track Weather Satellites and download weather data
  • Program Radios with CHIRP
  • Files such as manuals
  • Entertainment such as books, magazines, music, and movies

Let’s build our SHTF machine, shall we?
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What Can You Do With A Computer With No Internet?


This is one of my favorite subjects.  And it kind of goes along with being prepared for the worst. Small devices such as computers can be easily recharged or used on even a small solar set up. So what can you do with a computer when there is no internet?  Quite a lot actually.

I’ve done this before in 2018 with a Linux computer but I’m going to do it this time with a Windows laptop.  But it is time to update that post a little bit, I suppose.

And as per my previous recommendation you want to probably use an old laptop and preferably something like a ToughBook.   If the internet is down, and life is getting harder you don’t need some baby computer that won’t hold up.


Yep, your computer can be a TV with no internet connection.  You do need a USB TV Tuner though.  I use the Hauppauge 955Q which is probably obsolete since I couldn’t find it anymore on Amazon.  This seems to be the latest generation.  Despite which tuner you get make sure that it is ATSC and not PAL.  ATSC is US and PAL is European.   Your tuner combined with software called NextPVR or probably any number of software programs you can download will give you an Electronic Program Guide and allow you to watch Over The Air Live TV.  That program guide does come down from the internet though, and you won’t be able to access it if the grid goes down.  Still, you know what your local channels are though.

NOTE:  I probably should state that my grid down situation is most likely a hurricane and all the local stations are 40 or so (driving) miles away and inland so they will most likely still be operational.  Your situation may vary.

Being able to watch TV during a power outage or while you are Sheltering in Place could provide vital, life saving information.  Or it could just provide much needed entertainment in a bad situation.

NextPVR (click pics to enlarge)

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Selecting a Software Defined Radio (RTL-SDR)

RTL-SDR’s are COOL.  The list of things you can do with them is almost too long to list here.  But know that it ranges from “listening to the radio” to hardcore scientific atmospheric experiments, and everything in between.  Hackers can open your car door or garage door with them and private detectives can record the radio signals from your tire pressure monitors to prove you were somewhere you shouldn’t have been.  Remember the day when they used to have to sit for hours in a car and take your picture?  No more.

I recommend to anyone that will listen that they should have an RTL-SDR in their emergency kit.  When I went through Hurricane Florence in 2018 in New Bern NC all local communications went down INCLUDING the NOAA Weather Radio Station.  How’s that for a kick in the pants?  I watched TV anchors walk off the set due to flooding in their studios.  But the police and firemen and Linemen were still out there and I was listening as they restored power to my area.  Also having an RTL-SDR during a violent Hurricane KEPT ME ENTERTAINED and kept my mind off of things.  AM radio was my best way to stay informed but be warned that some of the SDR’s below need up converters (more hardware) to listen to AM radio or some geek skills to enable the device to listen to frequencies below 24 MHz.

Anyway…….how do you select what SDR you buy?  There are lots of them out there and I’ll hit some quick pros and cons on selecting them. If you go to Amazon and search, this is usually the first one that pops up.   The RTL-SDR Blog Version 3.


It may be one of the better general purpose receivers and is relatively low cost.  Let’s do some pros and cons.  There pros and cons are for FIRST TIME USERS AND BUYERS.  Not for old pros.


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Radio vs. RTL-SDR

I live in Hurricane country and it is hurricane season.  Everyone tells you to have a radio in your storm preparation kit, but they don’t specify WHAT radio but sometimes they will say “Weather” radio.  A decent weather radio will set you back $30 or so.  But then that doesn’t get you the local news.  So an AM/FM/Weather radio that is decent will set you back even more.  There are cheaper ones than I just linked, but not cheaper by much.

During Hurricane Florence in New Bern, NC the local TV stations bugged out and the NOAA weather station was damaged and stopped transmitting.

Power was out and there was widespread flooding.  And an almost across the board loss of LOCAL communications.  At this point you are left with the Ham Radio folks.  Also most people probably aren’t aware the AM radio signals can be heard for HUNDREDS OF MILES at night.  So if your town loses all communications, the next one over probably didn’t.  Or that big city 200 miles away inland didn’t.

Below is the AM band at 1AM from my location in Eastern NC.  660 AM is WFAN in New York and it is coming in crystal clear.  It is routine to listen to Louisville, Clevland, New York, Boston, Detroit, Atlanta, Canada, etc.  You can see how many signals there are of good strength.

AM Radio at 1 AM Eastern North Carolina

Anyway, even supposing you have a multi-band radio that doesn’t help you when most everything goes off the air.  Where are you going to get your information?
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Using an SDRPlay RSPdx Over The Network

Using an SDR device over your local network is pretty handy.  If you are like me your antenna connection for your SDR is in one place.   If you want to play “radio” you have to do it in that one place formerly known as “The Ham Shack”.  No more.  The Ham Shack can be anywhere in the house now.

Using an SDR over the network is nothing new but the various methods have pros and cons.   Essentially I want to be able to roll through 0 KHz to 1800 MHz from anywhere in the house.   In my previous blog I used an Airspy HF+ Discovery to stream to a Mac computer.  That worked perfectly but the Airspy HF+ does HF (plus a little more).   It doesn’t go 0-1800.

But my SDRPlay devices (RSPdx, RSP1a, and RSPDuo) do.  SDRPlay has some network Server software called RSP_TCP and let’s just call a duck, a duck shall we?  It’s crap.   It has limitations and it seems to be an abandoned project.  Go to their Github page and nothing has been done to the code for a couple of years.

But the folks at SDRPlay came up with an awesome solution to remote control a couple of years ago (which is probably why they bailed on the RSP_TCP project).

It is called VirtualHere.  I’ll try to make the explanation of that it is as simple as possible.
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Listen to Airspy Spyserver on a Mac

It’s been a hot minute since I played with my RTL-SDR’s.  I have an Airspy Discovery HF+ which is an amazing piece of hardware, however it plays best with Windows software, specifically SDRSharp (SDR#).

The trouble is I spend most of my life on a Mac computer.   On the same download page I linked above for SDRSharp is program called SpyServer.  You can set up your Airspy HF+ Discovery to serve up radio over your network.

The trouble with that is the best software client to do that is SDR# which is Windows only.  So in order to make it work on Mac here is what we will do.
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SDS200 And Proscan Software. A Powerful Combination

Uniden SDS200

Ever since I was a little boy, which may have been a few years ago, I have been fascinated with radio.  They had things called “World Band” radios when I was a kid.   I would sit for hours and spin the dial trying to hear far away places.  There was mystery, intrigue, challenge, exotic languages………these are the things boyhood is made of.  Not Drag Queen Hour 🙄. Then there was Citizens Band (CB) Radio.  I had one and was prolific on it.  What I really wanted was a ham radio and it took me a few years, but I climbed that hurdle as well.  I am now licensed as KN4FMV.

You might think I’m a weirdo however in the radio hobby probably the quintessential website for radio systems and frequencies is called   If you go to their web page you will see that there are almost 1.5 million subscribers.  So………I’m in good company.

So I dig radios.  And the older I get, the worse, not better, it seems to get.  I still spin the dial on shortwave radios, sometimes for hours. I have multiple Software Defined Radios (RTL-SDR’s) and I have police scanners, with the actual name of them being called “radio scanners”.

Every so often in any hobby one item will rise to the top of the heap.

In my opinion, in the world of Radio Scanners that device is the Uniden SDS200.  This is an advanced radio for advanced users.  Most places you buy from will preprogram them for you for free, so if you know nothing about radios or police scanners let me forewarn you that the learning curve could be STEEP.  Everything is well documented but to an outsider to the hobby it could still be confusing.
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Best Tech of 2019?

So here it is, New Years Eve…….I’m up at 1 AM and reading “Best Tech of The Year” articles.  Either one of two things has happened.  Either nothing tremendously wonderful happened in Tech this year or the imagination and writing skills of journalists are now nearly non-existent.

Every list shows the latest cell phones or drones, or gaming device or newest TV offering.  I’m sorry, but that just isn’t that inspiring to me.   I may be a dinosaur but newer is not always better.  Case in point.  Look up the home entertainment category and most lists have some SONOS player.  That’s a networked streaming audio system.

I’ve been using Logitechmediaserver so many years it isn’t funny.  It streams Spotify, Tidal, TuneIn, Pandora (I dropped my Pandora subscription) and many, many more services.

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