Monday, May 13, 2013

The Beatles On KAAY (Teenage Wasteland I)

The radio in my Mom's '65 Ford Galaxie 500 was pretty good. Nice bass response for a 6X9 dashboard speaker and instant-on thanks to transistors. We're flashing back to about 1965 here; there may be some fuzziness about dates, but the Big Picture is beaming in loud and clear. Every note is as pristine as it was Back When. The message will not end.

Every now and then, I'd catch a ride to school with Martha on her way to teach Biology at Malvern High. She had long since learned that the radio belonged to me and she was okay with it (loved her some Wilson Pickett, she did). Naturally, that radio was tuned to KAAY and cranked up as loud as she'd let it go.

I was fourteen and clueless (I would not know everything in the world until I was fifteen), but there was just something about Beatles records on my favorite station. Compared to everything else on the air in those days (with the great exception of Motown), they seemed to leap out of the speaker. They demanded attention, they dared you not to listen. I always tried for an extra notch of volume when one came on.

I would not learn the why of this audio magic until decades later, when I read George Martin's elegant book, All You Need Is Ears. He wrote about compressing Beatles recordings so they'd be as loud as possible when played on the radio. He and his team of engineers were also fascinated--and frustrated--by the amount of bass that Motown records could achieve. If they cranked up the bass on Beatles recordings beyond a certain point, the arm of the cutting lathe would jump up off the turntable and ruin the master. "We could never figure how the Americans were doing it."

Turns out there was some more audio magic at work up in Little Rock, where KAAY played those Beatles 45's on Gates turntables into a Collins vacuum tube console. From there, it was off to Wrightsville and into some more (huge, glorious, delicious, creamy, fat) tubes in the mighty RCA BTA 50-F transmitter. At the last minute, the sound would pass through Felix McDonald's legendary 70-cycle "choke," where anything below that frequency would disappear--and the remaining bass notes would get shaped and clarified, cut like a bodybuilder's torso. (To this day, Felix maintains that anything below 100 cycles is just hum.)

Oh. There was one other bit of magic afoot in those fabled days. On one of our morning rides, I discovered that I could predict when the next record played on KAAY would be by The Beatles. It only worked when I was in the car with Martha (go figure), but I hit it every time. Now what do you suppose that was?

David B. Treadway
Doc Holiday VII
The Last PD

Bonus Points: When I was grown and working for a living on the air, it disturbed me that every available version of Penny Lane was missing those seven piccolo trumpet notes at the end, which I was certain I had heard every time KAAY played it. Where had they gone? Had I only imagined them? Nope. The original promotional copies of the 45 had, indeed, contained that wistful signature at the end of the song. Subsequent mixes and releases did not. When you hit the link below, you can hear what we all heard on The Mighty 1090.

http://www.youtube.com/watch?v=sH8f-HGsgJ4

1 comment:

  1. Hollis W. DuncanMay 25, 2013 at 2:56 PM

    Felix was right. Anything below 100 cycles or so on AM radio is wasted power. And because low frequencies stay there longer, they eat power that could be applied to the "music frequencies."

    In general, telephones are limited to 300-3000 Hz and we all agree that this is inadequate, so the choice of a low-frequency cutoff is a judgment call.

    On the other hand, the FCC requires Am stations to pass (relatively) flat and (relatively) distortion-free frequencies down to 50 Hz, so it may be that KAAY would not pass an audio proof of performance with the 70 Hz hi-pass filter in place. But KAAY of my era would not pass an audio proof at all.

    Capacitors get old and the first thing to go is the low frequencies. Because the circuit is designed to work with the proper value of capacitance, the result can be low-frequency distortion of the low frequencies. Because distortion tends to generate harmonics and because those harmonics fall up in the "music frequencies," low frequency distortion can raise havoc with processing and the audio.

    It gets worse. Harmonics aside, Intermodulation Distortion can cause one part of the audio to "modulate" another part of the audio. As an example, if you were speaking while I was injecting a distorted 50 hz wave that was rich in harmonics, you might not be able to hear it but it might modulate your voice at a 50-hz or even a 150-hz rate, Even if we couldn't identify the effect, we would all agree that it sounds pretty weird in an undefinable way. When you hear an AM station that sounds weird, they probably have some Intermodulation Distortion thin their chain.

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