INTERPRETING THE RCS-4B DISPLAY

11-5820-917-13

EL9TE033

E f f e c t of Range on HF Propagation.

m a t e l y 2.4 MHz. T h e l-hop mode shows the characteristic splitting of the 0-mode

and X-mode. The upper part of the display shows received power vs frequency.

It can be used as an indicator of frequencies with greatest received signal

s t r e n g t h , however care must be taken in extrapolating such data if the sounder

system utilizes different antennas than the communication systems on the circuit.

7-19. INTERPRETING THE RCS-4B DISPLAY

7 - 2 0 . I n general, the "best" communication frequencies are those showing the

following characteristics (in order of importance):

A nearly continuous trace on the CRT throughout the band of interest,

preferably near the MOF.

b . Maximum received signal strength on the upper bar graph (some sacrifice

i n signal strength can sometimes be advisable if use of a much higher frequency

is possible).

M i n i m u m multipath propagation or total time delay spread.

7-5