Quite often I am asked how easy it is to hear numbers stations. First, it doesn't take much in the way of a receiver. You can hear them on anything from a cheap, portable SW receiver to the most advanced high-end receiver. Generally, you can use the same receiver you use to tune in pirates on the HF bands. Any receiver covering the entire HF spectrum with AM and SSB capability will be sufficient. A digital frequency display is ideal.

The hardest part of listening to numbers stations is to be on the right frequency at the right time. Numbers stations, like pirates, don't publicize their schedules, and they often use seemingly random frequencies & times. They normally avoid the amateur, maritime, broadcast, and aeronautical bands, but they have often been found there. For the most part they use frequencies in the fixed services bands. I have also noticed a tendency to use frequencies that are close to the edges of different bands. For example, the Cuban YL/SS station that can be found on 6983 at 0200 Fridays. 6983 is, of course, just below the 40 meter ham band. Some of the Cuban stations also use 4017 and 4028, which are just inside the 4 MHZ maritime band and next to the 75 meter ham band. Numbers stations usually use quiet, unused freqs so as to not cause interference to legitimate users, but this also is not always the case. A couple of years ago I heard several MARS stations commenting on a numbers station that had disrupted their net.

One thing I always look for when spinning the dials is an AM carrier with no modulation. If you find one on a freq outside of the broadcast bands near the top of the hour, it's worth keeping an ear on. Most stations that use AM turn their carrier on a while before the actual broadcast. It also helps to become familiar with what signals you usually hear on different frequencies to spot those signals that are out of the ordinary.

Another question that I was recently asked is, "Why do you listen to numbers stations when you can't decode any of the messages?" While we can't decode any of the messages, it is a challenge to match your wits against those in the intelligence community. Since they don't publish frequencies or schedules, part of the fun of chasing numbers stations is finding them. A bigger challenge is actually trying to identify the agencies behind different stations. Huge clues have been gained by hearing little mistakes made by different stations, like the Cuban stations that accidentally play Radio Havana programming from time to time. It has taken an incredible amount of monitoring by numerous SWL's over the years to provide all the information we currently have on different stations.

Of course I think the thing that keeps me interested the most about numbers stations is the fact that none of them officially exist. Don't believe me? Try getting any information about them from any government agency. You're bound to get a reply along the lines of: "We cannot confirm or deny the existence of..." and "...we are not presently disposed to comment on such activity, if in fact it does exist." Trust me, it's been tried before. I must say, though, that if we knew all the answers to the mystery of spy numbers stations, they wouldn't be nearly as intriguing.

Speaking of intriguing, Tom Mazanec sent me an interesting item that he is not sure actually happened or not. It seems that in the early days of FM radio, a spy numbers station went on the air on the IF frequency of the FM radio recievers (possibly 10600 KHZ), and everyone in that part of the country (upper penninsula of Michigan) could hear only the numbers broadcast on FM no matter what station they tuned to. The numbers station changed their frequency in record time. Tom asked me if this actually happened or if it is plausible. I admit I never heard of it before, but perhaps someone out there may have heard of it or even experienced it. If anyone knows anything about this, please let me know.

That's all for this month. Next month I plan to take a look at the Cuban numbers stations and their skeds.