Icom IC-7851 Instruction Manual page 2

FOREWORD
Thank you for choosing the IC-7851. The IC-7851 has many built-in high tech-
nology circuitry and unique functions, such as the Dualwatch on the Main and
Sub bands, a high speed spectrum scope scan, a high-resolution waterfall
screen, and many other outstanding features.
The internal frequency signals in a radio utilizing a PLL are not always suf-
ficiently pure. This results in a considerable number of unwanted spurious
components, called phase noise, in its frequency spectrum. We focused inten-
sively in drastically reducing the phase noise of LO (Local Oscillator) because
the phase noise degrades the interference rejection and noise characteristics
of the receiver. As a result, we succeeded in developing an LO with high pu-
rity outputs so that results in an RMDR (Reciprocal Mixing Dynamic Range)
of 110 dB with newly developed 1.2 kHz Optimum Roofing Filter. Currently no
competitors have been able to achieve this extremely high result performance.
We believe we would not have been able to exceed the standard specifica-
tions without our full focus on LO purity.
In addition, Icom that has chosen to base the IC-7851 on an up-conversion,
double super-heterodyne receiver design, which has many advantages over
traditional receiver designs.
We are proud to have developed the IC-7851 for your amateur radio activities,
and hope it brings you years of enjoyable operation.
Please read this instruction manual thoroughly before using the IC-7851.
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