EAMs are Flash Override precedence -- the highest priority, and many comm systems are set up for what's known as ruthless preemption -- a Flash Override message will seize the comm circuit for the EAM transmission, no matter what other comms may have been taking place by another user (including safety of life). That's a reason safety of flight/safety of life comms could be switched to a discrete freq whenever possible.
Back during the SAC Giant Talk network days, EAMs were given out at standard time periods, in addition of course to the potential for an EAM to be given out at any time. The routine EAM broadcast windows were known as "Alpha Monitor" periods, Alpha being a code for SIOP forces.
I believe what you're referring to as "Skyking" broadcasts were (& still are) Force Direction Messages -- important broadcasts, but lower priority than an actual JCS-directed EAM.
Hmmmm…I believe an issue here might be terminology. I have said it several times in the past, most listeners do not really know what kind of messages they are hearing on HF-GCS, and make some assumptions about them. Hobbyist have picked up the term EAM and apply it to all encoded “longer” traffic on the HF-GCS network, essentially anything coded that does not start with “Skyking, Skyking, do not answer” is called, by hobbyist, an "EAM". My response is (or was meant to be, but I see I should have worded it differently) that most messages that hobbyist call EAMs fall below Skyking in priority. And you are probably quite right that there is a confusion of EAMs, Skykings, and FDMs. However, I believe what most hobbyist hear and call EAMs are actually FDMs. For example, I have heard up to 20 "EAMs" (or what the hobby has called EAMs) in one hour (although 4 or 5 are more common), it seems unlikely to me that there would be that many highest priority override messages for hours on end. And yes I do understand the concept of lots of transmission, most with no value, to confuse opfor.
What I can say, for sure, is that more than once I have heard a Skyking preempt an in progress “EAM”, at least what hobbyist refer to as an EAM.
T!
(edit)
It would seem that several other sources agree with my order of priority on the HF-GCS.
http://www.cvni.net/radio/nsnl/nsnl000/nsnl0f.html
•All GHFS traffic will cease for an EAM transmission.
•All GHFS traffic will cease for a FOXTROT transmission.
•All EAM transmissions will immediately terminate for a FOXTROT bcst.
It further defines Skyking as a FOXTROT
http://www.monitoringtimes.com/html/eam.html
"These messages appear to have higher priority on the GHFS voice circuits than do the EAM transmissions as an EAM transmission will be terminated in midstring in order to immediately transmit these "SKYKING" DNA broadcasts."
