Category: Towers of Power

We started playing with software defined radio! I’ve always been curious about them, and the in class demonstration piqued my interest even more:

Broadcasted cats! Courtesy of Dhruv’s two minute pop-up radio station at WITP 1015.2 FM, sponsored by internet memes and cats.

We were asked to look around on the spectrum and find “something interesting”. Thought it might be good to figure out my limits to start. GQRX is the application that interfaces with the SDR USB dongle. It seemed to automatically stay within the limits of the hardware, between about 23 Mhz and 1,740 Mhz. Starting from the bottom and scanning upwards, the first signal I spotted was at 23.583 Mhz:

The recording interface works pretty well in GQRX, but some of the signals were pretty quiet, especially compared to the static that surrounds it. I’ve posted some recordings, unedited besides normalization processing to boost the quiet audio to audible levels:

 

Moving upwards, I spotted a larger waveform and a conspicuous spike on the signal scope. I needed to adjust the receiving bandwidth to properly hear what was going on:

Wasn’t expecting music this clear so low on the spectrum, as traditional FM broadcasting does not go as low as 24.539 FM. This could be something like broadcasting muzak for a elevator, building, or shop.

I decided to switch things up, and start from the highest frequency and then work down. There was a lot of static at first, but then I spotted a possible signal:

At first, it sounded like nothing. Not nothing like just static, but nothing like no noise tucked inside of a lump of static. I was going to move on to the next signals when I thought I heard something.

People talking? I looked around and realized that it was a briefly delayed version of what was happening in the room I was in. I had to boost it REALLY loud for you to hear it as it is now. I tried refining the SDR settings and searching nearby bands:

I thought I was going crazy, but I was sure I was hearing audio of the room I was in. Luckily Dhruv was there to consult, and suggested that the wireless mics setup off of the floor could possibly be the cause. I shared this with Grau, who may be expounding on it in his post.

While I was talking with Dhruv, police officers came onto the floor. No one was sure why they were there, so he suggested tuning into their radios to find out. He showed me the following website to find the frequency for the local police radio band: http://www.radioreference.com

Interesting to hear, it almost seems like the signals switch back and forth between bands. I’m not sure if that was two different devices each sending on their own channel, or perhaps some kind of channel hopping system.

It was fun going in blind on the frequencies. I had decided not to google anything at first on purpose, but the radio reference is really interesting and I’ll be searching around for fun frequencies to look at. Especially things like wireless mics or cameras!

Our assignment was to get OpenVPN working on a device, connected to a pre-setup server with keys generated for us.

I installed openvpn and ssh on my virtualbox Ubuntu machine pretty easily. Using ps aux | grep ssh allowed me to see that ssh was running. I have a little bit of experience in bash command line, so things were coming back to me and I was starting to get comfortable.

Long story short, one of the steps in the directions threw us off. The wording as a little confusing and me and a few of my classmates spun off in different directions trying to read documentation and figure out if we were doing things correctly. It feels like no big thing when written out in a short paragraph, but we spent the better part of two hours trying to figure out “where the client.conf file was supposed to be generated?!”. Turns out a separate email was sent telling us to download an example from a github page. d’oh.

 

Don’t want to ramble about my troubles, but there are all kinds of fun hurdles when you aren’t truly experienced in the command line.

But if I needed to sum it up:

https://xkcd.com/149/

 

Though, I finally got it working:

Shout out to Mithru, who was a huge help. The command line is a cold place. Take a friend with you when possible!

 

The reading was Built to Last chapters 3 and 4. Glad we’re coming back to this book in the assignments. “Preserve the core and stimulate progress” was the take away for these two chapters.

Again, I’m not coming from a business background. But I am getting some good motivation and high level ideas from this book. While there are points where I think that the author dwells a little too long on one idea when it is probably safe to move on, I wind up appreciating the direct and emphasized summary of the philosophy. These aspects seem like they should be easy to grasp, come up with, and follow. But I’m sure many companies have thought that, and failed because they may not have truly adhered to the “core and progress” model in a way that is sufficiently fanatical.

I see parallels with personal art practices and life goals, as well. But even disregarding a translation into other areas I am interested it, it is nice to see these types of thoughts floating around in a business book. It is tempting to be cynical about business. I’m glad to see a earnest and potentially positive take on some of these issues.

Plenty to think about. Not sure how specific a core value can or should be, but I keep returning to thinking about what my company’s core value would be.

Starting in Towers of Power, our initial assignments were to setup an Ubuntu environment in VirtualBox (done!), find our IMSI and IMEI numbers for our phones, and read the first two chapters of “Built to Last” by Jim Collins.

 

My experience with finding my IMSI and IMEI numbers was interesting. First, Googling what they are. The IMSI is your phone’s International Mobile Subscriber Identity, and the IMEI is the International Mobile Equipment Identity. My understanding is that the IMSI is based around the SIM while the IMEI is based around the device itself.

The IMEI can be found in an Android system by going into the Settings>About Phone>Status>SIM Status. There is also the option to dial the number *#06# in the dialer and then the number pops up.

But I couldn’t find the IMSI. Googling around seemed to indicate that some Android phones have it in the settings, while others don’t. Some people claimed that the number printed on your SIM card was your IMSI and others disagreed. Then in Googling, I saw that there were plenty of Android apps that could tell you your IMSI… but I got paranoid. You aren’t supposed to give that information away, and I was having trouble trusting any of the apps not to harvest my data.

I wound up calling T-Mobile customer support, who informed me that my IMSI is the same as my IMEI. I’m partly skeptical of this answer as being something a customer service rep might say just to get someone off the line, so I’m going to follow up on this with Dhruv and Edwin.

 

“Built to Last” was interesting, and having us stop at the end of chapter two felt a little bit like a cliffhanger, so I will be coming back to it when I have the time. I’m not necessarily the most business oriented person. And when I am it is more about having an idea for something I would want to make and then perhaps building a business model around it. This isn’t the ethos of “Built to Last”, nor of many of the tech/app economy types we usually get exposed to. But I did come to appreciate what Collins was positing.

I kept thinking of the word “sustainability” and how it has so much more meaning than in an ecological sense. How do you have organizational sustainability? In some of his examples of “clock makers, not time tellers” he talks about the United States and the intentions of the founding fathers to build a system that outlasted any one lifetime. I like this idea in an of itself, but also the realization that this organizational sustainability doesn’t need to be solely business oriented.

If you wish to obtain a more abstract goal, value, or set of beliefs; that often isn’t just about reaching it once and then proclaiming victory. It is a thing that needs to be reproduced and maintained continually. Clock making, not time telling. Teaching to fish instead of giving fish. Seems like a worthwhile art to study. And not only is it practical in that sense, but I appreciated the idea of having these core values be grounding in a way. Nice to think of being able to meditate on a strong and simple belief when navigating hectic terrain.