Determine the received strength of a transmitted signal     
To gauge shortwave pirate radio activity in 2017, I analyzed the Shortwave Pirate loggings forum of the HF Underground (http://www.hfunderground.com). A computer script parsed the message thread titles, as well as the timestamps of the messages. This information was used to produce some statistics about the level of pirate radio activity. Of course, as Mark Twain has written: “There are three kinds of lies: lies, damned lies, and statistics.” A fourth might be pirate logging message titles. Don’t expect all the numbers to exactly add up. Still, let’s see what we can learn.
There were 13,903 messages posted to 2,550 unique threads. Activity levels are essentially flat, but still at historically high levels. Back in the 1990s, it was not uncommon for an entire month to go by with only a handful of pirate stations logged. If you want to know when the “golden age” of shortwave pirate radio was, I would say it is right now.
Ideally, each thread represents an individual pirate station transmission. Also ideally, each message posted to a thread represents one logging. In reality, there is some error involved. Let’s dive in.
First, we can look at the transmission mode used:
AM and USB are tied for first place, with everything else essentially noise.
Next, we can see how much activity there is for each day of the week:
As one might expect, Saturday and Sunday are the big winners, with Friday in third place. But don’t give up on weekday listening! About a third of all transmissions are on a Monday through Thursday.
We can also look at the number of logging threads per month, to gauge activity:
Not much of a summer slump as in past years, activity is relatively constant throughout the year.
We might be interested in knowing the best time of the day to try to hear a pirate station. Here’s a plot of the start times of the logged broadcasts, binned
by UTC hour of the day:
Peak activity in the evening hours is clearly evident, but there is still a good amount of morning and afternoon activity, and low amounts at random overnight hours.
Here’s a graph showing the number of broadcasts per day of the year that were logged:
Looks like the peak was Labor Day weekend?
Finally some graphs of logging threads per frequency:
And zoomed in vertically to see the less commonly used frequencies:
6925 is still the big winner, and 43 meters overall is where most activity resides, but there’s still lots of pirates to be found elsewhere.
If you’re interested in hearing pirates, the best ways to keep up to date on what is being heard is via the HFUnderground.com message board, as well as the real time Rocket Chat. Rather than finding out about a transmission after it is over, you can tune in while it is still on the air. Also visit our Facebook group.
And of course, your loggings and other posts on the HF Underground are most welcome! This is how we find out what stations are being heard.