Total posts : 45366
Like many PhilB posts, the above note on NRSC AM PreEmphasis is a printout for filing in my AMT5000 file-folder.
This last paragraph is packed with important meaning:
“Part 15 AM antenna Q is a real Catch-22. The higher the Q, THE BETTER THE RANGE, but the narrower the bandwidth. The ‘sweet spot’ for best range and fidelity is a compromise. Given the crippled audio response of today’s receivers, IT’S PROBABLY BEST TO GO FOR HIGHER Q TO INCREASE THE RANGE.”
Now, me Carl Blare speaking, I would like to tack-on what I think is an important COMPANION IDEA to support the practice of INCREASING RANGE THROUGH BETTER Q.
I have found that certain careful equalization of narrow bandwidth audio can sound surprisingly clear and life-like. The perfect example is a small loudspeaker in a portable radio that sounds amazingly rich.
I might have an article or two in my audio files regarding the science of tailoring an audio curve to maximize the audio output from a small loudspeaker.
If the AM transmitter is viewed as a small loudspeaker, I believe it is possible to maximize the Q (range) and the fidelity (apparent audio quality).
I’ll return to this theory as soon as I can locate some documentation.