AM or FM?

When I look around social media, I see a lot of posts that declare that AM was better than FM is now. And depending on my mood, I tend to agree more than disagree.

Left: A RCA 833-A tube, similar to the one used at WIS AM Radio in the late 70s. It was huge; 9 inches from top to bottom! This is not about the geek measurements such as frequency response and signal to noise ratio. FM wins those hands down, especially in the modern era where there is so much noise on the AM dial that was not there back in the day. It is more about the warmth and the feel of analog music played through the hot final tubes of a well run AM transmitter instead of across cold transistor arrays being driven by over-processed digital signals.

As much as it is about the media, it may be more about the music itself, and folk of a certain age who’s attitudes towards newer music is similar to the attitudes our parents and grandparents had about rock and roll of the 50s and 60s. They hated the devil’s music that we all listened to on those 7 transistor analog AM radios that graced the shirt pocket of every cool guy and the hip purse of every hot kitty in high school. Think about that when you complain about the next rap song your grandson plays.

So, when school was out and we were on the bus headed for home, the earphones were strung out and popped into our ears. This was eons before someone called them ear buds. There were two types, singles and two piece; one earphone for each ear. I preferred the two piece kind myself despite the sound being monaural. Even when I began using headphones in radio, I could not stand the one piece headphones that a couple of my fellow DJs preferred. The reason was simple; the two piece headphone put you in the center of the music and blocked the rest of the world out. I was in heaven, far from the roar of the diesel engine in the back of the bus as it wound its way through the city streets towards home. Yeah, it was all about the sound.

We did have an announcer or two from the Gary Owens School; where an announcer cupped a hand behind one ear to capture the sound of his or her voice. You remember him from Laugh In, I’m sure. In the few times where I was caught having to announce without headphones, I did that myself. Better than nothing but not too satisfying.

It’s hard to explain the satisfaction of hearing your voice mixed in with the atmospherics on an AM station right in your ear. We were required by FCC regulations to monitor the station’s air signal while we did our shows. The sound changed from winter to summer. In the winter, you could hear a slight hiss along with an occasional pop or thump that brought the visualization of your voice travelling out across the city. During the summer the experience was more like being in a war zone competing the static and rumble of thunderstorms in the afternoon or evening.

Transmitters themselves had a particular voice. For example, when I was at WCOS AM in Columbia SC, we had a Gates 1,000 watt daytime transmitter and an RCA 250 watt transmitter for the nighttime hours. Despite the lower power, I loved the sound of that RCA transmitter; it was rich and hot and had more soul than the more powerful daytime transmitter. I enjoyed that RCA sound again in the late 70s at WIS Radio where we had the RCA BTA-5T 5,000 blowtorch. From the DJ position at the audio board, I could look through the glass window into the transmitter room and watch the bluish-purple corona dance across the exciters and final tubes as I spoke. I remember one time, things were not sounding right. I looked over at those tubes and did not see the corona. That night, I swapped out the RCA 833 final and the two RCA 4-125 exciters and voila, the corona and the awesome, rich and warm sound was back. Who knew that you needed the blue!!

In today’s FM systems, the sound is cleaner, the frequency response better but to me it lacks the soul of the old AM signals. What’s more, we are not required to listen to the on air signal by the FCC. That is a good thing too, because if it was required we would not be able to do that. What you hear on your radio is delayed from 10 -20 seconds behind what the DJ is saying. In the case of WUSC-FM, it is about 18 seconds; 8 of which occur when the transmitter processes the digital signal it gets from the studio line into analog FM and into HD 1 for our listeners with HD receivers. Just like digital TV, HD Radio allows for up to four different programs to be transmitted on the same frequency. The other ten seconds of delay comes from our digital delay system in the station. This allows the DJ to “dump” the last ten seconds of what was transmitted in the case where something was said that should not have been; I.E. profanity. This is why we can’t monitor the off the air signal like we used to in the AM days.

I miss being able to monitor the transmitter and hear exactly what the audience hears. At least one of my former coworkers hated that more than I did. He ran his headset levels just below the “sonic boom” setting. Another was constantly “tweaking” the monitor levels when presenting to get a sound that only he could hear. As for my “sonic boom” friend; when he could no longer monitor the on air signal with all the processing that was between the board and the transmitter, he convinced the station’s broadcast technician to build a parallel audio chain complete with all the processing to feed his headphones so he could hear almost the same thing that the audience heard. You know, I completely understand his passion. Oh MY!