[ARC5] CW Keying Wheel

[sbjohnston at aol.com]

 The decline in AM listening started with the increasing commercial spot loads on the stations.  People started to choose the competitor, FM, which had fewer spots and the programming formats there became more fashionable.  FM is now overloading their stations with commercials, driving people to internet-based programming sources.

The decline of AM was aided with the decreasing quality of the receivers - the manufacturers made them ever more minimalist to save costs.  Also perhaps even more important:  Every vague report of "interference" to the car radio makers (Delco confirmed this to me) led to a reduction in the next model's IF bandwidth.  This was the only way they could deal with these vague complaints at no or very low cost.  Home radio makers followed the lead of the car radio companies.  

The standard IF bandwidth of AM radios declined over this period to the point where many later radios have trouble reproducing anything beyond 2.5 or 3 kHz!  That's a big reason why people are so amazed at how good old AM radios sound. 

Good-sounding modern radios do exist, but you have to search for them and they cost more.  This narrowing of the receivers' bandwidths over time also helped steer programming format choices on AM to talk shows, sports, etc. and less music.  Voice was still listenable on the current radios.

The final nail in the AM coffin will likely be the ever-increasing and apparently now unregulated noise which impacts that mode and band more obviously than FM and digital TV.  But the noise is troublesome on FM and TV too - people just don't recognize the issue as high noise levels.

See my paper on this topic:

http://www.wd8das.net/IEEEpaper-Growing-Radio-noise.pdf


Steve WD8DAS  

sbjohnston at aol.com  
http://www.wd8das.net/  
http://af4k-crystals.com/  
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