Another in the Thinking Ahead series started with https://k9zw.wordpress.com/2019/09/10/im-a-ham-or-am-i/
Considering “When to Put Your Radios Away in preparation for Troubled Times” one has to recognize that it is the nail standing proud that gets the next hammer blow.
If the situation is such that being on the air can cause trouble for you, it is time to put your radios away.
RDF (Radio Direction Finding) is a mature technology that will pin point your transmitter in situations where their are consequences for being on the air. The military had Ground Surveillance Radar operators (GSR) who basically had a radar strapped to their chest to look for the enemy. Well the enemy figured out how to ID the GSR operator and shoot them. It was said that in the Vietnam War a GSR operator battle lifespan was measured in a few days.
So (surviving) GSR operators learned to displace themselves from their antenna, which seemed to work for a while, until the enemy got wise to the ruse.
RDF of receivers is also a reality. In countries with TV license taxes their governments include the use of RDF in how they track down unlicensed TV receivers. The way this work is receivers do emit coherent energy, which can be sensed.
Continue reading