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Part 15 AM Coverage - High vs. Low Carrier Frequency

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A NEC4.2 analysis shows this, for the system described:

  • 2.8-meter, Base-fed, Base-loaded, Vertical Monopole
  • Monopole Base Elevation = 0.2 meters above the Earth
  • R-F Ground = 16 Buried Radials, 3 meters in length (each)
  • Radial Common Point Concentric with Vertical Axis of Monopole
  • Earth Conductivity = 5 mS/m, d.c. 13 (about average)
  • Applied R-F Power at Loading Coil Input = 80 mW, unmodulated

At 1650 kHz...

The Basis for FCC NOUOs to Part 15 AM Operators

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FCC §15.219(b) limits the total length of the antenna, feedline and ground lead to 3 meters.

A review of Part 15 AM NOUOs issued from FCC field inspections shows that if an installation does not meet §15.219(b), then they revert to §15.209 to judge its compliance.

If that inspected system is producing a field intensity at 30 meters greater than permitted by §15.209, THAT becomes the basis for an NOUO, rather than non-compliance with any part(s) of §15.219.

So ultimately, those NOUOs are based on excessive field strength.

A Mystery

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Someone on a hobby broadcaster website recently posted that the FCC does not keep track of old ham licenses.

Subsequently in that thread, he posted that he applied for a "vanity" ham callsign first used by someone that abandoned it about 50 years ago.

That FCC callsign (K8CBZ) first was issued in 1956 to yours truly, proof on request.  I didn't renew it because my interests evolved beyond ham radio toward commercial AM/FM/TV broadcast operations and engineering -- a career path I followed until I retired in 1999.