Figure A2-2. Skywave Propagation

TM 11-5820-919-12

Figure A2-1. Ground Wave Propagation

Figure A2-2. Skywave Propagation

effectiveness of different segnlents depending on the

communicate with stations on the other side of the world

time (less than 100 miles and between 100-500 miles,

The winter months are better than the summer months

respectively).

because of the high summer static level especially in

equatorial parts of the world

A2-13. 2 thru 5 MHz. This band is useful during

A2-15.10 thru 15 MHz. This band is the best choice for

daylight hours for intermediate and short-range

skywave communications and good for long range

reliable intermediate and long range commi8nication

(several thousand miles) during the light. The static

during all propagation condition. During very low levels

level is highest during the summer.

of sunspot activity , the band will not be useful at night

but improves greatly at dawn and holds up w ell until

dusk.

A2-14. 5 thru 10 MHz. This band is similar to the 2

thru 5 MHz and except long-range communication is

A2-16.15 thru 25 MHz. This band is highly variable and

possible) during daylight hours under good c(conditions

(high sunspot activity . The signals follow the

quite dependent on sunspot activity. When conditions

darkness path best and during winter it is possible to

are good , it will be useful during day and

A2-2