Everything You Ever Wanted To Know About the JRC NRD 545
What does that control marked TONE in the lower right corner of the NRD-545
(But Were Afraid To Ask)
For reference, here is the spectrum in AM mode at 6 kHz bandwidth with the
Tone control fully clockwise:
Next I rotated the Tone knob counter clockwise, and took several spectrums.
About 10 o'clock:
About 9 o'clock:
About 8 o'clock:
The intended effect seems to be to roll off the higher frequencies, and start to peak
around 1 kHz, presumably to bring out frequencies in the spectrum used by speech.