No, Clark, the first IF of the Corsair is NOT 6.3 MHz. That's only the
Bandpass Tuning IF of the RECEIVE IF. The transmit IF is still at 9 MHz
as is the first receiver IF and the product detector. The cure for 17m
is that the Local Oscillator mixing is on the high side (27 MHz) instead
of the low side (9 MHz) which puts the standard sideband on Lower
instead of the use standard of Upper. But the spur is gone because its
from the LO not the IF signal.
The LO second harmonic comes out of the mixer nearly as strong as the
desired mixing product. That's what makes the spur.
73, Jerry, K0CQ
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Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.
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