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Random Thoughts

Radio Waves

Hudson Cooper
Posted 4/22/22

One of my fondest memories growing up was listening to Yankees and Mets baseball games on my transistor radio. To avoid the wrath of my parents when it was bedtime, I placed the radio under my pillow …

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Random Thoughts

Radio Waves

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One of my fondest memories growing up was listening to Yankees and Mets baseball games on my transistor radio. To avoid the wrath of my parents when it was bedtime, I placed the radio under my pillow and secretly listened to the broadcast. I never considered how the radio transmission was able to reach me even though we lived far away from Shea or Yankee Stadium.

Transistor radios were hand-held devices that allowed me to hear the radio broadcasts of everything from baseball games to rock and roll. Occasionally there would be interference caused by an unknown disturbance between the transmitter and my tiny battery operated, wireless transistor radio.

The concept of wireless transmissions is the basis of this column. Look around your location. Your world is surrounded by routers, satellite discs, cell phones, Wi-Fi, GPS, laptop computers and other wireless devices all sharing communication. Your domicile is probably situated in an area where all your neighbors use similar devices. By the way, the term Wi-Fi does not mean “wireless fidelity.” It is just a user-friendly term created by a marketing firm.

I am fortunate to be a co-host on the third Friday of every month on the radio show Thunder 102 with “Paul Ciliberto and Friends.” By using the internet, friends of mine from all around the country can hear my voice even if they reside outside the radio station’s range.

It got me wondering how radio transmissions can be broadcast with all the other types of signals zipping around the atmosphere. I consulted with Ariel von Volt an expert in the field of wireless transmissions. She is currently putting the finishing touches on her book about Wi-Fi entitled “Piercing Thin Air.” At first, I experienced numerous failed attempts to call her cell phone. Eventually, Ms. Von Volt called me. She apologized for not keeping our scheduled time to talk claiming that her cell phone service at her home was not working. Luckily, a nearby Taco Bell had Wi-Fi and so after ordering a Crunchwrap burrito, the attendant gave her the secret password “chalupa,” so she could phone me.

It turns out that all systems that transmit through the atmosphere use multiplexing. This has nothing to do with your local multiplex movie theater that has twelve screens but only one concession stand. To purchase your extra-large popcorn, half gallon of Mountain Dew, boxes of Milk Duds and then find seats for your family requires planning akin to what Eisenhower did for D-Day.

Allocating air space for the various wireless devices requires frequency multiplexing. It involves assigning gigahertz and megahertz frequencies to the various devices. For example, the GPS system in your car that tells you that it must “recalculate” because you missed an exit, operates on either the 1.57542 GHz or the 1.2276 GHz frequency band. Wi-Fi is sent by way of 2.4Ghz and 5Ghz bands. FM radios stations are assigned to various MHz bands depending on the station’s location.

Within each band there are frequency channels that are used to avoid interference among the multiplexing devices. As Ms. von Volt started explaining things like spatial diversity, code time division and polarization multiplexing, my brain was turning into chalupa. Luckily for me her allotted Wi-Fi time at Taco Bell ended and she had to hang up.

As an aside, the business name Taco Bell has nothing to do with anything relating to “good or pretty” taco. The company was founded in 1954 by Glen Bell who opened “Bell’s Drive-in and Taco Tia” in California. In 1962 the name was changed to Taco Bell when he opened his first dine-in restaurant. So, like McDonalds and Wendy’s, Taco Bell is named after a real person. That naming process does not apply to Little Caesars. When Julius ruled Rome, he never envisioned “stuffed crazy bread” or a “3 meat treat pizza.” He was too busy trying to conquer the Gauls and wondering why someone circled March 15th on his appointment calendar.

Unseen by us, the surrounding air has all types of information, music and cell phone conversations zigging and zagging around. Wireless technology has exponentially exploded in the past few decades. But often I miss the simpler times when it was just me and my transistor radio under my pillow. I enjoyed listening to Phil Rizzuto say “Holy Cow” as he described a Mickey Mantle home run.

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