I have heard so much about (as far as what they may or may not be) them in my searches for listening. I have seen some YT videos, and heard speculation on them but what is the opinion of the members here?
A common misconception is that numbers stations are a hold over from the Cold War. In fact such stations far predate the Cold War, and even predate World War II.
Lets get the basics down. A numbers station, in the context most often used, is generally NOT military (with a few probable exceptions). There are military transmissions using coded groups of letters and numbers, but just coded groups does not make something a numbers station. For that matter there are weather reports that use groups of numbers and letters that are sometimes confused for numbers stations.
What are they? Some of them, likely the majority, are probably spy or espionage related (this is particularly true of the long running “traditional” stations). In at least two cases the US government has indicated in court records that specific spies operating in the US have gotten direction from numbers stations. One of the guidelines of the Enigma and Enigma 2000 group (the groups that assigned the identifiers, such as V02, E06, G06, etc) was that the station had to be a suspected spy / espionage / intelligence related station to receive such a designator. Known military or “other” stations transmitting groups of letters and numbers were oddities, not numbers stations. Of course there is a gray area when the transmissions are known to come from military complexes but still thought to be intelligence related. A few times military stations were erroneously given spy numbers station identifiers, but often once assessed as military the numbers ID was withdrawn. For example, station M21 was eventually assessed to be Russian air defense related, and so that designator was withdrawn. M31 was eventually assessed to be French military and the designator was withdrawn.
Stations such as Yosemite Sam and the HF-GCS / EAM transmissions are NOT numbers stations.
As for the transmission sources, in several cases (but still the vast minority) the actual transmission site has been identified by RFDF techniques. In many cases the general source area is known.
It has been said there are fewer numbers stations today than during the Cold War, I am not sure this is true. In recent years numbers station activity in Europe has diminished. However activity in Asia has increased. I believe there is roughly the same number of stations active today as at any one time in the past, but many of them (Asian) are hard to hear in the USA and Europe, where the majority of numbers station listeners reporting to forums like this are. However there used to be a pretty active group of Japanese numbers station monitors. Unfortunately, many of their receptions and findings did not find its way into the English / European language monitoring community.
In recent years several Oriental language numbers stations have been given designations, most of the “new” stations designated in the last 10 years have been Oriental. I personally suspect, but have no proof, that several of these are military related. It can be hard to get your head around the use for a station when not only the language is foreign, but also the thought processes can be a little different.
T!