I don’t normally listen to the 2.5 Admins podcast. When I saw that the latest episode was talking about AM Radio I figured I would tune in. The trials of AM Radio have been a bit of a topic on the World of Radio discussion list that I participate in after all.

The problem encountered with the episode was how confused the discussion got around AM radio. I wanted to break down a few matters in a blog post since they were not handled all that well by the podcast. Most of it revolves around emergency notifications to the public.

In the United States we have AM radio playnig a key role in the Integrated Public Alert & Warning System (IPAWS). The Emergency Alert System (EAS) is just one single component to IPAWS. The Wireless Emergency Alert (WEA) is another component to it. NOAA Weather Radio (NWR) also falls under IPAWS when it comes to providing alert information. The Common Alerting Protocol that runs IPAWS is XML-based so conceivably it can be extended in the future to do things nobody has thought of yet. Having IPAWS provide a one-way pipeline to the various generative AI chatbots could get interesting provided those bots could reliably convey the information from the feed.

There are 70 or so “primary entry points” nationally for messages to originate in the system. They’re all reinforced AM radio stations that happen to be on historic “clear channel” spots on the broadcast dial with large broadcast contour footprints. The closest national primary entry point to me is WTAM AM in Cleveland, for example. The federal government has paid to upgrade and reinforce those radio stations to keep them running in the event bad things happen.

As to the alerting system, it should be looked at as being similar to Markdown. A human being can look at something raw that was styled in Markdown and generally still get the meaning without needing a parser. The use of a parser allows for greater access to richer content.

The same thing goes for alert message blasts on the radio dial. By itself a human being will hear the shrill noises at the start of the message to warn them something is wrong and they’ll wait for the voice message to play out. Those shrill sounds at the beginning of an alerting message are actually data that you can hear. The data is being pushed in the style of audio frequency shift keying at an odd bit rate with even odder mark and space tones for the text blast. Suitable receivers can decode those blasts at the start of messages and pop up categorical warnings for listeners or even tell listeners if a message is not for their area.

AM is relatively simple to receive. The episode cited crystal radios as being no-power possibilities. Considering the level of disaster this country has seen ranging from forest fires destroying much of the west to hurricanes wiping out the Caribbean, we want to reach people who may have had their means of tuning in frankly destroyed. Tuning in FM with a crystal radio is a matter we need not discuss here.

Yes, electric vehicles are very noisy electrically and put out quite a bit of radio frequency interference. They may not pollute with hydrocarbons but they pollute in their own way. I haven’t looked to see if electric vehicles are banned out in the national radio quiet zone in West Virginia or not but I assume they are.

AM radio has its place. It has been a lifeline keeping the community informed in Puerto Rico when disaster strikes. It serves a key role in keeping IPAWS running. It serves you even when cell phones encounter problems trying to disseminate emergency information as found in an FCC tech report on WEA operations issues.

Overall the episode was good. The AM radio topic just continues to get weird for those of us with operational knowledge of the field. Hopefully things improve…