Category Archives: Uncategorized

2018 Flights

I used a website called to map out my travel during 2018. I’m pretty pleased with the geographic distribution, but there are some notable destination cities missing that I’ve frequented in the last couple years: Washington, DC; Raleigh; Boston. Let’s see what 2019 brings.

Bad Blood

John Carreyrou’s novel Bad Blood chronicles the story of Theranos, the company started by Stanford-dropout and prodigy Elizabeth Holmes that reached a peak valuation of $10 billion. I started this book and couldn’t put it down.

It was pretty shocking to read about the level of deception and dishonesty perpetrated by the company and continually tolerated by partner companies, the Theranos legal team, and the company’s many high-profile investors. The book is definitely worth the read and will surely be a business school case study on due diligence and corporate responsibility for years to come.

Top YouTube Picks – September 2018

I’m long overdue for a blog post, so I thought I’d share some of my YouTube favorites from last month (in no particular order):

1) Rich Rebuilds – Rich has made a name for himself by completing the herculean task of cobbling together parts from two different salvaged Teslas (one flooded and one in a serious crash) to produce a fully-working Tesla Model S. The catch is that Tesla does not endorse such homegrown repairs and will not sell parts to Rich or others. Rich has become the de-facto leader of a community of Tesla owners who want to repair their own vehices. Motherboard did an excellent profile of Rich, linked here.

2) An Aerial Viewpoint – I’m not exactly sure how I stumbled across this channel but a YouTuber based in Fremont, Ohio has chronicled the removal of the Ballville Dam. He’s captured daily and weekly updates of the demolition process via drone footage.

3) Handeeman – This couple has built an off-grid compound in the Sonoran Desert in Arizona. Most interesting to me was their techniques to harvest large amounts of rainwater for bathing and cooking.

4) Last but not least, NBA Fans Making Half Court Shots For Money/Cars Compilation

Small Cell Bonanza

I find cellular infrastructure fascinating. As a technological society, we’ve made a tradeoff: we accept the presence of thousands of large, unsightly antennas perched on tall free-standing towers or on top of buildings in the midst of our communities in exchange for ubiquitous connectivity. To be fair, various communities (European cities and California come to mind) have come up with clever ways to ensure that this infrastructure is camouflaged through zoning restrictions, “tree towers” and the like. But, if you’re like me, then you can still find it.

Camouflaged “brick” antennas

The smartphone that you carry every day has a radio, just like the AM/FM radio in your car. It transmits and receives information from a transceiver that’s mounted somewhere high in the air. As cellular networks were being developed by Bell Labs in the 1960s and 1970s, the original designs used a single centralized antenna to serve a metropolitan area.

Depiction of central antenna covering the Chicago area from the AT&T Archives

Since then, cellular networks have been built on the principle of radio spectrum reuse. This now hilariously dated YouTube video from the AT&T Archives shows the difference in cellular network performance in Chicago before and after the implementation of AMPS, the first cellular network in the United States to use this technique.

Because the amount of radio spectrum allotted to cellular networks is limited, the principle of spectrum reuse is to utilize the same radio frequencies across many different antennas that are geographically dispersed. These distributed antennas transmit and receive at lower power levels than they would in the single, centralized antenna model shown above. By using this technique, the limited amount of radio spectrum can be used again and again across an area. That’s the general principle although there’s quite a bit of nuance involving radio frequency slicing and other techniques that prevent interference. Today, the leading wireless companies have deployed hundreds of thousands of cellular sites in this manner. These companies also work with the FCC to free up additional radio spectrum for use with their networks in order to raise capacity.

This now brings me to the topic at hand, the proliferation of small cells in cities around the US. While downtown Chicago has had a robust cellular network comprised of both macro-cells and small cells built out over many years, the buildout of small cells is now extending to other reaches of the city. The demand for high capacity data and voice capabilities makes sense in a more dense downtown area with commuters, large events, and more residents. However, it appears that the wireless carriers have reached a tipping point at which less dense areas of the city still require more capacity and have decided to initiate a wide-scale buildout of small cells. This is certainly a capital-intensive project but the carriers likely believe that next generation wireless or “5G” will require an even denser network of cells. I live in the Ravenswood area and have witnessed a huge amount of new small cells built out on light poles throughout the surrounding neighborhoods. I think this is a great thing for the city on the whole – we’ll have more reliable cellular signal and increased data capacity.

However, these small cells are just plain ugly! Compare the Verizon Wireless site on the left at Montrose and Ashland in Chicago to the site on the right in the Financial District in San Francisco.

Verizon small cell at Montrose and Ashland in Chicago

Small cell on light pole in Financial District in San Francisco










Both are situated on light poles but the San Francisco small cell is far less noticeable and appears to blend in with the pole itself. By contrast, the Verizon small cell has messy wiring and a bulky appearance.

Zoomed-in view: Verizon small cell at Montrose and Ashland in Chicago

To be fair, some of the other similar-looking Verizon small cells that I’ve observed around the city appear to have been installed with more care. I encourage Chicago city officials to enact stricter requirements on companies such as Crown Castle and Verizon Wireless to manage the appearance of small cells. It doesn’t have to be a tradeoff – we can have great coverage and keep our streets beautiful at the same time.

Why Everything We Think We Know about Health Care Is Wrong

The dramatic title of David Goldhill’s book Catastrophic Care caught my attention. I bought it, read it, and have now recommended it to a dozen or so people.

Goldhill describes the current state of the healthcare industry as an “island” unto itself. Due to many factors including regulation, history, and the legacy of government entitlement programs, the island operates quite differently than the “mainland.” The mainland, Goldhill states, houses all other industries such as banking, retail, travel and more. Because the financial incentives are vastly different on the island and the mainland, major differences in consumer satisfaction, quality, and pricing have appeared as a result. While industries on the mainland have been transformed by consumerism and digital technology, the island remains isolated, inefficient, and low-tech. Worst of all for the American economy, prices on the island are highly distorted.

The main drivers of this distortion are what Goldhill calls the “Surrogates.” The insurers, both private and government, are placed between you and me, the patients, and our healthcare providers. This gulf between the consumer and the provider causes mis-aligned incentives and financial distortion that doesn’t exist in other more consumer-driven industries. Driving the point home, Goldhill breaks down what a young employee at his company can expect to pay into the U.S. heathcare system over her lifetime and the findings are alarming. If you want to be a part of the healthcare debate, I’d highly recommend this book.

Review of Georgia Tech OMSCS

As of Fall 2016, I’m enrolled in the Online Master of Science – Computer Science, dubbed “OMSCS”, at Georgia Tech.

A few different personal goals led me to enroll in the program: 1) to obtain an advanced degree to aid in progressing towards more senior roles in my career; 2) to accomplish point #1 in a cost effective way; and 3) to keep my technical skills sharp.

I’m happy to say that this program has met and exceeded my expectations in addition to helping accomplish my three goals above. I can’t say enough good things about the program, but I’ll let the New York Times describe what makes this program special.

In spite of being a completely online program, the community aspect of the OMSCS is especially strong. I find that students are more engaged due to the availability and “always on” nature of the online class forum (called Piazza) than in my on-campus Computer Science classes during undergrad. With a large population of students across the globe participating in OMSCS, odds are that your question will be answered quickly by someone in some timezone at any given point in the day.

In addition, the course technology gives the OMSCS several advantages. For example, I can watch the Youtube-based lectures on my own schedule, versus a defined class time each week. Also, when a professor or TA holds office hours, it’s typically recorded and posted for all students to review. During my undergrad, if you had a conflict during the scheduled time for office hours, you were out of luck. Finally, for courses that involve closed-book tests (2 out of 4 of my courses thus far), advanced proctoring software allows you to take the test in the comfort of your own home. While this does involve the personal privacy sacrifices that come from being recorded via webcam and microphone, it does help to ensure the program remains high quality and worthy of Georgia Tech’s top ranking in the Computer Science field.

I’m currently in my second semester of the program and have taken two classes each during both semesters. With a full time job alongside the OMSCS, it’s a very demanding schedule. However, the program allows students to complete courses at their own pace, even one per semester, with a maximum of a one semester break in between.

All in all, it’s been a fun ride participating in what appears to be, by many accounts, the future of education.

The Mike Holmes of Stereo Repair

Adapted from an email I sent on December 9th, 2015:

I bought a “vintage” stereo receiver (made in 1979) on Craigslist mainly because it looked cool. I’ve been wanting to add some speakers in my living room for music since I’m tired of the computer speakers on my desk. They aren’t bad but just sound a little sterile and boring to me. As a bonus, I knew my parents had a record player lying around unused so I wanted to fire it up, something that I could only do with an older receiver that has phono inputs. I got some Micca MB42X speakers on Amazon to use with the receiver.

Back to Craigslist: The guy said everything worked but it turns out the right channel was blown. I could have used two speakers on the same channel, but they’d both be the left audio feed, bummer. I think he probably knew it was broken. Oh well, he lives too far away to go back.

I decided to search around for someone to fix it. There’s a crummy electronics shop right near my apartment that I went into but it turned out that their reviews are awful on Yelp. It didn’t surprise me as the store was chaotic and disorganized, equipment scattered everywhere. I guess electronics repair isn’t exactly in demand these days.

I hunted around a bit on Yelp and came across these guys. All 5 star reviews. I sent them an email asking for a quote. They quickly replied and said that for a price of $119 to $169 they’ll rehab the whole unit and give a one year warranty on everything – not just the damaged components, the whole receiver. Judging by the photos on their website and the Yelp reviews, they are the real deal and know exactly how to restore these things. Their website describes how the main technician was an apprentice to an electronics repair guy starting at a young age.

However, there’s no address posted on the site or the Yelp page. The guy emails back – great, they’re located in the Rogers Park neighborhood not too far from home. He says come after 6pm. I Google StreetView’ed the address and it looks like someone’s house or apartment rather than a commercial building. Weird, but I thought “let’s give this a shot.”

I arrived after work around 6:15pm, went up the back stairs to the 3rd floor like the email said and Casper let me in. Guy in his 30s in a sweatshirt, looks normal, has a slight lisp, ok. Kind of white like a ghost, come to think of it. He led me back through the apartment which had a ton of old-looking receivers and jukeboxes and parts lying around. Everything was very, very neatly arranged. The whole apartment had a very cool vibe and was mostly dark except for some neat LED accent lighting. He has a big screen in the kitchen with about twelve security camera feeds showing.

Then we got to the workshop – again, wow, incredibly organized and equipment stacked everywhere. It was somewhat dark in that room except for the bright desk lamps shining on the workbench. Newports on the table. Big-ass speakers mounted on the wall for testing. An array of meters (multi-meter, oscilloscope, other gizmos I didn’t recognize) on the bench. He took my broken receiver, popped it open, and said he knew the problem. That was within about 10 seconds. He then talked me through the whole architecture of the device and how certain transistors power each channel. As he went through each component, he took the multi-meter and told me which exact voltages should be showing – left channel appeared to be in spec, right channel was definitely fried. A couple resistors had burned up and the transistor that powered the right was also not working correctly. This crash course was a little over my head, but I could at least understand some of what was going on with my background as an occasional electronics hobbyist.

I realized later that Casper’s the kind of guy you’d want around if you were living post-apocalypse or even embargoed Cuba for that matter. Seems like he could fix anything.

After examining the receiver he asked if he can be frank with me. I say of course he can. “This thing is a piece of s***. I will do whatever you want me to do, and I can fix this, no problem. I just don’t want you pouring money into a crappy receiver. It’s dinged up, scratched up, and not that great of an original build anyway.” I replied that, while I appreciate the honesty, I really just wanted something that looks cool, sounds decent, and will power a record player.

He said he’ll hold on to it until I made a decision of whether to go forward with the repairs. He also offered to call a guy who sends a lot of equipment his way. Casper “doesn’t do sales” but often does work for this guy who “flips” vintage receivers and sells them. He recommended another unit which he had just restored personally for the flipper, and I ended up buying that one the very next day. Casper could have taken my money but didn’t.

Long story long, it was a pleasure to see a true expert apply his trade and with honesty to boot. P.S. don’t trust Craigslist.

Is Staying In the New Going Out?

I don’t have much to add to this excellent T Magazine Article: Is Staying In the New Going Out?

Let’s strip away the censure, for a moment, by analogizing the trend to personal wealth management. If we define “capital” in this metaphor as a mixture of our time and emotional stasis, then staying in is the ultimate conservative investment. It’s like pouring your money into a savings account: You’ll grow marginally; you’ll stay safe; your expectations will be met and never exceeded. The worst-case scenario is that your delivery fries are soggy and your premium cable TV episode is a B+ instead of an A. You can always pull the ripcord on your show and go to bed early. A failed night means that you got a good night’s sleep. That’s still a win. A modest win, but a win.

Timelapse: One Year on North Paulina Street

About one year ago, I installed a camera out my street-facing window.

The timelapse below is composed of hourly still frames from 6AM-7PM between March 25th, 2015 through March 25th, 2016.

The location is North Paulina Street in Chicago, IL across from Ravenswood Elementary School.

Keep an eye out for sewer construction, parking tickets, and more. Enjoy!

Plane Tracker Project

I built an airplane tracker. You might call me a nerd, I’d say I’m just curious about what’s going on around me.

I live in Chicago, home of O’Hare International Airport (ORD). While Hartsfield-Jackson in Atlanta is the champion of the world in terms of passenger volume, O’Hare is perpetually fighting for the #1 spot in terms of “aircraft movements” – basically the total of arrivals and departures over the course of the year.

Regarding my location: I live close to Lake Michigan, but almost on an exact line with the O’Hare flight path coming off the lake. If you live in this neighborhood and you don’t notice all of the planes flying around, you must be blind or deaf.

Since the runway layout at O’Hare was reconfigured a couple of years ago, air traffic controllers run planes in and out of the airport according to east or west flow. 70% of the time, planes land and take off westward, leading them directly over my building at a pretty low altitude. The other 30% of the time, planes come and go facing east. Finally, a very small percentage of the time, wind and weather force ATC to use O’Hare’s diagonal runways. Here’s a picture that shows the difference between east and west flow:

O'Hare East/West Flow

Long story short, a friend passed this link on to me, detailing someone’s Raspberry Pi-powered airplane tracker in operation near LaGuardia Airport in New York.

The documentation at the original link is pretty decent, and after ordering the parts and putting everything together, I have a working airplane tracker!

Plane arriving from LAX

Here are a few of the details you’ll need besides the instructions linked in the original blog post:

  • Soldering skills: you need these to put together the Adafruit LED screen. Turns out I am terrible at soldering, but somehow just barely good enough to do this project. I had only one row of lights on the display that did not function on the first try – re-soldering one of the pins did the trick. It’s probably worth it to practice first and then try your hand on the LED display afterward.
  • Python dependencies: Jeremy’s original code references a few Python dependencies (requests>=2.7.0, geojson>=1.3.1, shapely>=1.5.13) that I did not have installed on my instance of Raspbian. You’ll need to use apt-get or pip to pull them down. I also had to change #!/usr/bin/python3 to #!/usr/bin/python in one of the code files, as I don’t have Python 3 installed on my Pi.
  • Location: within the code you’ll need to program in your home airports (KORD and KMDW in my case) and coordinates where you want the software to look for airplanes – I used to do this.
  • LED screen driver: follow the Adafruit instructions closely, especially how to install the library that makes the LED screen function (you need to run the “install” function or nothing will happen).
  • Kernel module fun: to use the RTL2832U software defined radio on my Pi, I had to run the command sudo rmmod dvb_usb_rtl28xxu before I was able to get it to operate.
  • The code currently doesn’t display international arrivals, and will always display the closest plane to your location. I’ve noticed that the screen sometimes jumps between arrival flights as they land in parallel at O’Hare and both take turns closer/farther from my building.
  • All in all, fun & cheap project to learn a little more about what’s going on in the skies just above. Special thanks to Garreth for the soldering assistance.