Improve Antenna TV Reception and Detect Interference using the RTL-SDR USB as a Spectrum Analyzer

[@videodude8137]

GR8 tutorial on the Spectrum-analyzer App. I have the rtl-sdr v3, RSP1A & RSP1B. Have only started to explore this topic, so I was glad to have found your channel. Thank you from Alabama.

[@palawanese1067]

thanks for the insights kind sir. watching from palawan,philippines. :)

[@robertogalvez3865]

Very instructive video. I learned a lot. Thank you.

[@andrewborntrager7909]

Keep doing what you are doing! Is it possible to take the data from an SDR and extract the raw binary data, just zeroes and ones, that could be saved and later analyzed in different ways?Can't believe i just discovered your videos. It's only a matter of time before you go viral!

[@DoubleALabs]

Thanks! Yes, this plugin for SDRSharp can be used to record the raw data from an SDR, called an "I-Q file": www.rtl-sdr.com/new-sdr-plugin-if-recorder/ Because SDRs have a limited bandwidth (~2.4 MHz for the RTL-SDR), you can't record all frequencies at once, only the bandwidth the SDR is tuned to at that moment.

[@conrads84]

Nice video, thanks for link to software i will do some test in europe ;)

[@christianmiller1723]

Hello from Brookline, Pittsburgh! I've been using a cheap square, plastic TV antenna, an RTLSDR, and electrical tape to receive satellite signals lol. Being up here in the south hills, the elevation helps to give me really good reception of just about anything. If you're ever interested in hanging out and talking about SDR / Radio let me know and I'll give you my email.

[@James-oh4xd]

Awesome video! Can you tell anything by the shape of the signal? Like multipath, etc?

[@DoubleALabs]

Thanks for the comment, James! I only recently read about how to identify multipath from the shape of the spectrum, so I can answer your question now : ) Basically, unexpected notches in the spectrum are indicative of multipath. Multipath causes two or more copies of the signal to be received, each with a slightly different delay. This causes some, but not all, frequencies to destructively interfere (i.e., cancel out). I've linked an example from an actual spectrum analyzer below: www.avsforum.com/threads/atsc-3-0.1995418/post-62278084

[@RobbieStrike]

Are you able to pick up ATSC with the RTL SDR or is that a separate program? Would love to know what program can do that! Great video!

[@DoubleALabs]

Thanks, Robbie! That is a separate program and hardware (WinTV v10 using my Hauppauge 955Q as hardware). The issue is that, due to limitations of the USB 2.0 spec, the RTL-SDR can only sample at about 2.4 MHz maximum, meaning the maximum bandwidth it can tune at one time is 2.4 MHz, not enough for the 6 MHz channel width of an ATSC station. The wideband spectrum analyzer only works because it sweeps quickly across the selected band in 2.4 MHz chunks.

[@RobbieStrike]

@@DoubleALabs I wondered why you cant use a Haupauge for a SDR as well. I have done this in gqrx to see if my antenna was pointed in the right direction! Do you know of a program that works well in Linux that will do this?

[@DoubleALabs]

​@@RobbieStrike So, from what I understand the RTL-SDR contains a chip that was originally designed for TV reception (the European standard, DVB-T), but someone figured out the hardware could be "hacked" to deliver IQ samples from frequencies of about 30 MHz - 1.8 GHz (and direct samples below 30 MHz). IQ sampling is kind of complicated, but basically if you multiply a radio frequency by a cosine wave at that frequency and, separately, a sine wave at that frequency, you can shift all of the data modulated onto that carrier down to baseband ( pysdr.org/content/sampling.html ). The RTL-SDR contains the hardware necessary to do this. For tuning DVB-T, I believe the RTL-SDR chip does some processing onboard so it doesn't have to send the entire 6 MHz over the USB at one time. The Hauppauge may not have the hardware ability to do IQ sampling. Or, maybe just no one has messed with its hardware and driver to see if that is even possible. As far as Linux goes, I only use it on a very occasional basis these days, but I suppose you could try the Spektrum version for Linux.

[@ericmuehlstein2238]

Awesome video. I wish that utility wasn't Windows only 😭

[@DoubleALabs]

I haven't used it, but there is a Linux version. What are you using, a Mac?

[@ericmuehlstein2238]

@@DoubleALabs Yup. I spent the morning trying to feed rtl_power reading into influxdb to see if I could create something reasonably similar but no luck yet

[@bjs2022]

“Bad sound makes good video look bad.”

[@DoubleALabs]

Well, bro, you can send me some money on Patreon to help me get a better mic. I wasn't going for audio perfection here, and I really don't think the sound is that bad.

[@bjs2022]

@@DoubleALabs Your voice over sound was good but not your stand up presentation. The world is perceived as differences. You don’t know what you don’t know. Rhode now has good, relatively cheap combined-unit (mike+transmitter) wireless microphones that cost about as much as that Antennas Direct UHF antenna. Anytime a microphone is more than about 10 inches from your mouth you’re going to have reflected sound from the room (“bathroom sound”). Early on, Tyler the antenna guy started using a body microphone so he always has good sound.

[@DoubleALabs]

@@bjs2022 Thanks for the input. I used to be a theater technician who worked with wireless body packs and various types of lavalier and over the ear microphones, so I am familiar with "best practices". I currently have a full time job that's not KZbin and just didn't have the time for an elaborate production. The vo stuff was recorded with my phone 😂 right next to me as I sat at my PC. There's a spot or two where it glitched a little because my phone isn't exactly the beefiest.

[@bjs2022]

“Bad sound (no, awful sound) makes good video look bad.”

[@DoubleALabs]

Had to comment the same thing again, 5 months later?

[@bjs2022]

@@DoubleALabs Thanks, I thought I might have commented earlier but you’ve had five months to repost it / fix it with a voiceover so you could have normal / good intelligibility.