[Spooks] Re repeat NS messages

[EI0DB]

The major problem with messages via NS is the variability of the 
ionosphere. While the effects of the time zone offset between TX site 
and the agent, together with seasonal and sunspot cycle effects can be 
factored in and calculated into the choice of frequencies, [ normally 
from two to four with the transmissions going out either in parallel or 
in cascade;   that is the transmissions go out one behind the other 
using one transmitter. But what cannot be programmed in are the effects 
of ionospheric disturbances, CMEs and the associated solar flares. Of 
critical importance to the agent in the field are the condition of a 
communications wipe caused by enhanced ionospheric noise burying what 
would otherwise be a perfectly readable signal day after day. It is a 
fair guess for that reason it is unlikely that NS would be used for 
signaling urgent or time critical  messages.

best 73s, Dave