Alarm Clock 7:23AM Effect

I have had the same old, cheap and fairly unattractive 'old-school' digital alarm clock in my bedroom for more than 20 years. It's simple, has analog radio tuning, and, you know, it's just one of those things that you don't really think about much.

Until lately.

Very recently I have noticed that the strength/volume of the AM sports talk radio station that I usually wake up to in football season tunes in at a much smaller volume than it used to. Ok fine - maybe the alarm clock has served it's 20 years and is at the end of it's life. BUT - More strangely, over a month I have found that at EXACTLY 7:23 AM, if the radio is on, the volume and reception of that station increase to what it should be (probably about twice the volume or more). This is very noticable and it happens at 7:23AM regardless of what time I had originally set the alarm to go off.

Unless someone can offer me a reason why this is happening, I will probably run the following experiments:

1) check to see if it's the station by changing the alarm wake-up station
2) is it AM-band only? try an FM station
3) is the 7:23AM effect only applicable if I use the alarm clock on the 'armed' setting? flip the radio off and on sometime before 7:23AM and observe
4) what time does the radio go back to the low volume?

I'm really curious - what possible explanations are out there?