Enter the complex world of SDR

Tune the radio to your favorite FM station , and as the songs base starts to rev you up. The hacker within asks, "how does radio"?

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Antenna, rf isolation, Micheal Ossmann,, Discover, I learn by pictures, comedy kinda, and more.

We are going to surf those invisible waves passing us every moment. Grab your boogie board, and let's ride em' waves together.

Keep in mind I am not an engineer, nor have i attended college.

Well some college, but that was for Psychology and this isn't related to that (Fraiser radio show, hehe get it? err sorry anywho).

This if for hackers like myself, who want to learn and play in the rf waves.I'd like to help make a decent introduction to this exciting technology.

The internet has become more difficult to find specific information, and we often find ourselves lost while researching, lost within links and ad's. These Links then lead to forums, which lead us to dead websites which starts this wild goose chase sitaution, which discourages most. Lets chop out surfing the world wide web, and get surfing the Software Defined Radio. This information is intended fpr the novice hacker.

Ultimately i hope to share my SDR mods,

experience and research and provide a better introduction to a play environment for both hardware and software aspects of the SDR.

Keeping in mind im not an engineer, my builds may be useless, or worse may be incorrect or harmful to your radio. So if you try something I have posted/suggested/speculated and it ends up kills your radio, harms you, or pets I urge you to remember build at your own risk..

*Well I see people are interested, and I've never been good at addressing large crowds.. Especially in this case with a crowd of 50 Hackaday, Real life engineers/Hobbyist's.

...Well actually I'm good at public speaking in person presenting to a crowd.. However via my written (Typed?) words, i often don't feel intellectual and to plow past that, I will ignore my flaw and keep writing like the 27 year old college drop out, american workforce minion that I am.

  • 20 × Aluminium casing bits Shileding and style are whats important
  • 3 × DVB dongles I got three ready for the adventure
  • 100 × Curiosity I got this in spades
  • 9 × Usb bits Female, male, we have to spilce these in order to move the radio away from the computer. SDR's and compters don't get along. You see they were once roomates and they got to arguing over bills... Voltage bills

  • What's that Rf sound like.

    Dr.Droopy Nayhey02/21/2015 at 05:20 0 comments

    Car key-fob, Ti chronos, walkie talkie. You can read about the signals. or you can see them here!

    I'll start off.

    When i lock my car with my key..clicky thingy

    Note :

    i captured Some of these using the awesome free software SDR# download it here.. Well via the link below

    Cool eh?

    Now you the reader may be asking

    "Dr D, how did you know where to look to find this sweet wave, for your lame car clearly average Joe isn't privy to such info".

    DR.Droopy says

    I looked at the internal label of the keyfob, and i found 315mhz. It said something like 315mhz and some patent jibba-jabber, and a bar-code" scribed within it's factory label ...

    So to recap i found the RF frequency etched upon the keyfob.

    Using this free software and the that cheap little DVB stick and setting sdr shrap to the printed freq and I click the LOCK button on my Keyclicky

    Ahoy! OOK (On/off keeying sent to my car rf language to tell my whip"Lock em doors up, son!")

    We will cover decoding it later, and for now dear sailor ; we simply seek to view the waves. Soon we may understand the waves, also we shall praise the great...

    Michael Ossmann

    Really though Michael Ossmann is a present day Zues... Except, instead of thunder Micheal Ossmann is God of RF THUNDER.. Webaite below

    Though to be honest I don't presently own a HackRF , nor do i Own anything built by the rf~ZUES, it's only because I make little more than minimum wage, and currently I have 35$ in the bank towards a HackRF

    Yup This is how i envision me, the hack RF and that ghost Knight from Indiana Jones.

    ...Moving on

    For my next trick; the same session, the same RTL-SDR, and the same madness i present...

    Using the cheap device we can migrate from the wild world of car locks to this radio station...

    NOW, you can say your friends in a raspy ex solder kinda voice

    "Have you ever seen a radio stations, have you ever seen it's waves"?

    *Sdr sharp is awesome, It's easy to use and gives you the proverbial binoculars to your 17th centenary search. My criticism of SDR# is purely based on the Dev being closed source.

    Or "Hey don't touch my awesome code, or I'll sue your balls to the walls". Which by all rights isn't a legitimate issue; more of a pet-peeve. I guess if i developed something that could make me mad cash I would be stingy on my softwares copyrights too..

    Well not really, I'd like them hackers to take my code and improve it. So let's Look at the same signals via other apps!


    Before we look at other software let me recap..

    Your car stereo, and your cars's keyfob are pretty much cousins. I bet you didn't relate the two, nor had any idea they were both waves in our RF surfing competition..

  • Conceal, keep it secret keep it safe.

    Dr.Droopy Nayhey02/16/2015 at 21:03 0 comments

    RTL-SDR in cool and unsuspecting cases

    This is going to be my work on a portable SDR, I always have one in my pocket for demonstration and to excite my friends... Though Sadly my friends think SDR is a gateway drug into Male Spinsterhood, and find not interest in the 7(ghz) Sea's. So This will be a later edition, for my current enclosures are from old rf equipment I've salvaged



    ~and not really what I plan on building

  • USB cable extension tips, pics, and the dirty things your computer doesn't want you to hear

    Dr.Droopy Nayhey02/08/2015 at 21:13 2 comments

    So that computer of yours, I'm sad to inform you that your PC is a RF menace, and the DVB tuner must connect to it.

    This isn't ideal for the SDR, it's like having a cell phone conversation while present at a Rock concert.

    So our first step is to build a DIY USB extension for the device(Or buy one).

    -you may be thinking

    " psh, stupid Dr. Droopy I have tons of USB extension cables already".

    My response

    Your EXTENSION CABLE isn't good enough , or may EVEN worsen your SDR experience. The USB Cable itself must be shielded to the RF rock concert around you/it. This is achieved by ferrite beads.. well they're like clip things.

    ~In addition, the USB extension Cable itself may be confused and inappropriately used as an antenna by your Rtl-sdr. Remember this thing is cheap, and originally was not designed for this type of rf surfing. So we must correct for this stupid device and how it connects to it's Computer overlord

    SO let's mash together a USB extension cable built with RF in mind.

    A usb extension cable is pretty common, I bet you have one right now... Coiled around you leg

    LOOK OUT!.........

    Seriously though take a look around, if you don't have one BAM let's make you one.

    Step One :

    *Gather the beads, broken usb cables and the ol' soldering iron

    Usb female:

    Old computer bits scattered around? Grab that old Mobo and lets remove some Female Usb connectors

    Every article i read on this was pretty much the same buy this buy that, and to this i say nah i can make it.

    Let's assume i used heat shirk tubed each connection. Which i did for an already built one, I took the end and placed it through a plastic holder which i had from an old usb extension cable. I also stripped away the metal shroud, less metal= mo bettah

    here is the end product

    Are you a bad enough dude to trust your solder job?

    No, you shouldn't assume it's all good.. Use a voltmeter to test continuity .

    once it passes your voltmeter we're ready for a trial run!

    use a USB device that means nothing to you. in my case an old flash drive.

    Heck yes! The USB Extension cable works!

    One bit i totally missed explaining was the ground wire.

    In the above example, we simply removed the metal shielding from the female end of the USB cable. We do this because the cheap tuner can mistakenly use the ground connection as an antenna. Which is not at all a good thing. If we were to insert our sdr within a nice case we would use the ground connection to connect to the metal shroud within the case. We will cover that when we build a case together... as a family

    now onto ferrite

    I found that the ferrite beads are pretty conman, and I already had several USB cables which already utilized them, so I just needed to perform bit of a USB Splice operation . So i suggest looking around, trying different ferrite cores, or buy the ones the recommend. The once i salvaged seem to perform just as good as the ones i bought.

    Actually I've done a lot of USB soldering in my day, and as we can see in my primary radio pic below I built a sort of USB break away system.

    Reason i had to design a break away system; is due to the amount of cables I've tripped over + it's good for portability! (Broken at least 10 devices by being drunk and somehow getting them tied around my legs, which I break with the hulk like power )

    So within that RF shielded case I have it wired to another externally attached (Glued) Usb connection. I'd open it up and show you the internal connection i made, but honestly i don't remember if i grounded through the top or bottom of the case, and I really don't want to re-do solder work. We will make an rf shielded case later in this project so don't-cha worry

    The case errr..

    ~ This case

    Rf drop amp, I work within the telecom field.. So i have access to discarded treasures. Such as this discarded rf drop amp.

    I gutted the device and basically assumed if it works for that it will probably work for this. Since I enclosed the Rtl-Sdr in this drop-amp shell I have noticed nothing but improvements.

    Before using this enclosure...

    Read more »

  • Bought a cheap dvb stick, now what?

    Dr.Droopy Nayhey02/08/2015 at 20:53 0 comments

    Often this is posted within forums, and as comments to articles about software defined radio. No matter what the post contains we often see something like this. "Hackers use DVB dongle to reveres engineer the 70's song Do The Hustle" ; and the first comment is something like this. Jeff6969 commented "How do i hack friendface with sdr PLZ".

    Something tells me knowledgeable hackers, engineers, and the pope absolutely hate this type of comment. I know I hate seeing these when I'm trying to figure something out. Obviously these comments are posted by someone who hasn't done their homework, and if it's one thing I've noticed about the hacker community it's don't ask stupid questions. Personally I have found myself wanting to ask questions on forums, or articles but avoid doing so because even though I think my question is relevant it may be seen as just as stupid as the simulated post above. That and I hate having to go through an account creation to ask a question, and pray for a reply.

    So you got an rtl-sdr eh?

    I will assume you at least got it installed and went through driver madness, now your reading everything you can. However still a shadow of confusion hangs over your head. Discouraged you place your new toy in a shelf, and return to your seamonkey farm. Forgetting the fun you could of had, but due to so much information you couldn't get a stable idea of the Who, What, and why of the device. This was me, well kinda I don't have a seamonkey farm (The instructions got to complicated, and the forums i read informed me these aren't underwater primates as I had hoped). I returned to the sdr after a series of other project failures, and deceded f*** it i'm going to read EVERYTHING I CAN. Even if it was a series of trigonometry calculations that i couldn't even begin to understand I'm going to force myself to read it. I also saved up the $10 for the

    The Hobbyist's Guide to the RTL-SDR: Really Cheap Software Defined Radio

    Which $10 doesn't seem like much (Hell i forked out 12 for the sdr) but at the time I was stuck in a lease for an apartment i couldn't afford. I URGE you to buy this book, It slapped me and brought me from the depths of discouragement right back to the euphoria of hacking.

    That's the link... moving on

    The "now what" is up to you, i guess i could have started with this statement. However I have ADD and never scored well on essay writing. So with this neat little DVB stick there are many possibility's

    1. You can track aircraft.
    • This seems like it's one of the most popular uses of the device. Personally I don't quite understand what's fun about tracking aircraft. However to each their own. I will cover this, and will attempt construction of a suitable antenna It is neat and a fun demonstration of it to your friends, though mine gave me a weird look and asked so?

    2. Hear, and track trunked police, fire, and EMT radio conversations.

    • Pretty neat, though I live in a small town so it grew old quick. After about 20 minutes of 2 police officers discussed a errant tire which was on a pubic road.

    3. Hear FM radio

    4. Discover weird a wild things transmitting.

    • This is the closest thing to being an explorer as the average man can be. I often wish i was born in the 1700 because exploration seemed so accessible. The rf spectrum is tantamount to the sea of the 1700's, well not really; but it's ripe for discovery.

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Enjoy this project?



PointyOintment wrote 01/22/2015 at 05:07 point

Looks like you've accidentally created this project twice.

  Are you sure? yes | no

Dr.Droopy Nayhey wrote 02/08/2015 at 21:36 point


  Are you sure? yes | no

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