Tag Archives: NDB

Enhance Your Wi-Fi Mojo With Old-School Radio Hobbies

I have this odd love of some really arcane signals. With a modest but decent receiver from Tecsun (the PL-880), I take advantage of the winter months in the northeast (less atmospheric electricity and no thunderstorms) to “hear” these quirky Longwave signal churn out slow Morse Code identifications. It’s utterly addicting to the right-minded radio geek, and also draws large parallels to what goes on with Wi-Fi that help reinforce my WLAN foundational knowledge.

For wireless networks , we know that output power, antenna choices, the environment where we’re operating, and the capabilities of the client devices all contribute to whether Wi-Fi is “good” or “bad”. If the signals can’t get through, then the microprocessors involved can’t turn those signals into data. Let’s talk about what it feels like to listen to NDBs for a bit, then how that relates to Wi-Fi.

I live about an hour south of Lake Ontario in the middle of New York state. With my beloved Tecsun PL880, I recently received an NDB signal from Pickle Lake’s little airport in Ontario Canada. This location happens to be several hundreds of miles away. The beacon transmitter (considered a “navigation aid”) at the airport generates a fairly low-power cone of  signal into the sky, more or less straight up (that’s the non-directional part of “NDB”). The intelligence in the signal is simply slow Morse Code continuously looping the letters Y-P-L. See this link for  information on the airport.

Pickle Lake

Given that any beacon is typically low powered and pointed straight up, finding them on the air from afar is a sport unto itself. Longwave spectrum sits below the AM broadcast band, way down where frequencies are measured in kilohertz.  It’s absolutely cluttered with man-made signals, and is at the mercy of natural electrical interference, like lightning strikes (called “static crashes” int the radio world). Yet I was able to discern that slow Y-P-L signaling from across a huge Canadian province and a Great Lake, making it an accomplishment as a signal-chasing radio hobbyist.

If you’re not familiar with Morse Code, that Y-P-L formats like – . – – / . – – . / . – . . (dash-dot-dash-dash/dot-dash-dash-dot/dot-dash-dot-dot).

In 802.11 WLAN, specialized modulation helps to ensure that the important signals prevail despite RF conditions being crappy enough to kill narrow-band signals. I see Morse Code is somewhat akin to spread spectrum when I’m chasing NDBs as the dots and dashes can often be heard through really bad conditions that would utterly destroy voice signals. (This is actually why Morse Code was created and used as a mainstream long-distance radio communications mode for so long.)

When Wi-Fi signal quality is degraded, data rates will decrease. When I hunt down NDBs like Y-P-L signal, I might have to listen to each for several minutes and manipulate the filters on my receiver before I know what I’m actually hearing- and sometimes I just can’t quite clarity.  For this and other radio activities, my own ears and mind are the actual microprocessor. Call me silly,  but each beacon identified is like catching a nice fish and brings it’s own little flicker of excitement. Here’s a great list of Longwave NDBs out there to chase, and there are many other lists to be found online.

For improved reception, I could connect my PL880 at to a better antenna, just like in Wi-Fi. I could improve my “data rates” (or words-per-minute copying) by using better filters and practicing my Morse Code more. This would make me a better “microprocessor” in this activity.

Really geeky stuff, eh? I have no problem wearing that label. I also know that there are other radio nerds out there in the WLAN community, as well as those who want to learn more about radio “stuff” beyond Wi-Fi. For those folks, I’ll be teaming up with Scott Lester to present “Radio Hobbies for the WLAN Professional at the 2019 WLAN Professionals Conference. Sign-ups start mid-December, and I hope to see many of you there!

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