Re: RE: Power and harmonics


From: chuck adams (
Date: Sat Dec 31 1994 - 01:21:14 EST


>From what you posted on the OHR 80M five element Chebyshev filter,
i.e. 620pF, 1200pF caps and 3.06uH inductances, here are the
attenuation factors in dB from 3MHz to 17Mhz generated using Spice.

     freq vdb(3)
  3.000E+06 -9.395E-01
  3.200E+06 -7.063E-01
  3.400E+06 -3.924E-01
  3.600E+06 -9.059E-02
  3.800E+06 -1.486E-02
  4.000E+06 -4.871E-01
  4.200E+06 -1.714E+00
  4.400E+06 -3.556E+00
  4.600E+06 -5.689E+00
  4.800E+06 -7.866E+00
  5.000E+06 -9.967E+00
  5.200E+06 -1.195E+01
  5.400E+06 -1.381E+01
  5.600E+06 -1.556E+01
  5.800E+06 -1.720E+01
  6.000E+06 -1.875E+01
  6.200E+06 -2.022E+01
  6.400E+06 -2.161E+01
  6.600E+06 -2.294E+01
  6.800E+06 -2.420E+01
  7.000E+06 -2.542E+01
  7.200E+06 -2.658E+01
  7.400E+06 -2.770E+01
  7.600E+06 -2.878E+01
  7.800E+06 -2.982E+01
  8.000E+06 -3.083E+01
  8.200E+06 -3.180E+01
  8.400E+06 -3.274E+01
  8.600E+06 -3.366E+01
  8.800E+06 -3.455E+01
  9.000E+06 -3.541E+01
  9.200E+06 -3.625E+01
  9.400E+06 -3.707E+01
  9.600E+06 -3.787E+01
  9.800E+06 -3.865E+01
  1.000E+07 -3.941E+01
  1.020E+07 -4.015E+01
  1.040E+07 -4.088E+01
  1.060E+07 -4.159E+01
  1.080E+07 -4.228E+01
  1.100E+07 -4.296E+01
  1.120E+07 -4.363E+01
  1.140E+07 -4.428E+01
  1.160E+07 -4.492E+01
  1.180E+07 -4.555E+01
  1.200E+07 -4.616E+01
  1.220E+07 -4.677E+01
  1.240E+07 -4.736E+01
  1.260E+07 -4.794E+01
  1.280E+07 -4.852E+01
  1.300E+07 -4.908E+01
  1.320E+07 -4.963E+01
  1.340E+07 -5.018E+01
  1.360E+07 -5.072E+01
  1.380E+07 -5.124E+01
  1.400E+07 -5.176E+01
  1.420E+07 -5.227E+01
  1.440E+07 -5.278E+01
  1.460E+07 -5.327E+01
  1.480E+07 -5.376E+01
  1.500E+07 -5.425E+01
  1.520E+07 -5.472E+01
  1.540E+07 -5.519E+01
  1.560E+07 -5.565E+01
  1.580E+07 -5.611E+01
  1.600E+07 -5.656E+01
  1.620E+07 -5.700E+01
  1.640E+07 -5.744E+01
  1.660E+07 -5.787E+01
  1.680E+07 -5.830E+01
  1.700E+07 -5.872E+01

You can see that 20M is down 51dB, 30M is down 39dB, and 40M is
down 25dB. Depending upon the spectral purity of the fundamental
I'd think that the harmonics probably meet FCC specs in this
country. It would be interesting for someone to put one on
a spectrum analyzer.

My $0.02 worth.

dit dit
Chuck Adams K5FO CP-60

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