Quote from K6AER: The FCC 50 watts minimum drive requirement is for amplifiers out putting 1500 watts. The actual requirement from the FCC is the amplifier gain is limited to 15 dB or less. Most of the K3 users are into CW so IMD is not as important to them as the audio crowd.
5B4AGN wrote:Initial encouragement by Freescale in the choice of the device was strong but experience has revealed problematic levels of harmonic energy at the output. Freescale now acknowledge this problem to be significant when using these devices at HF. They have quoted H3 at -7dBc and H5 at -13dBc being their experience. These figures are bad enough to require use of a power dumping diplexer at the output or development of some frequency adaptive class F filtering which seems rather impractical in a broadband amplifier. Extensive discussion with Freescale resulted in them saying, "Development of a wholly acceptable amplifier for this frequency range (1.8 - 54MHz) will be very difficult to achieve." I am wondering whether you have had better experience with harmonic levels or found a way to address the issue satisfactorily?
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