[ICOM] ICOM 746 PRO

[Adam Farson]

Hi Gary,

<< Icom has always been stingy on the SWR they will accept. >>

There is another reason why Icom is correct in folding back transmitter
drive for load VSWR > 1.5:1.

Quoting Sabin et al., "HF Radio Systems & Circuits", Chapter 12, pp. 483-484
(the section on PA linearity):

The collector-to-collector (or drain) load impedance must be maintained as
close to resistive as possible [for optimum linearity]. This in turn
requires optimizing the output wideband transformer(s), combiner (if used),
and low-pass filter passband VSWRs to as low values as possible."

It sounds great to support load VSWR of 3:1, but I would like to see a
2-tone test on a spectrum analyser under those conditions!

Cheers for now, 73,
Adam VA7OJ/AB4OJ

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