Callsign Prefixes in Top 50 DXCC 50wpm
Channel: Kurt Zoglmann
Date: 2019-07-16

These are the most common callsign prefixes for the top 50 DXCC entities. (See below for a detailed explanation and links to other speeds.) For each callsign prefix, try to head-copy it and determine which country it belongs to. First, the callsign prefix is sent in Morse code. Then it is spoken. And finally, it is sent again in Morse code. If you missed it the first time it, the second time allows you an opportunity to learn the callsign.

Additional Speeds:
15wpm — https://youtu.be/FNiLIAds-78
17wpm — https://youtu.be/Un_5hDyvLTg
20wpm — https://youtu.be/VVcLOzqptbk
22wpm — https://youtu.be/khUVnarhYN0
25wpm — https://youtu.be/5Orz99pa1EQ
28wpm — https://youtu.be/nowWH-J5AQw
30wpm — https://youtu.be/KgQCJ0JMQ9I
35wpm — https://youtu.be/bevqNLqeEog
40wpm — https://youtu.be/bhLyU9EWPdc
45wpm — https://youtu.be/graNpbLiSXM
50wpm — https://youtu.be/Mlyt25L61xs

Learning to head-copy callsign prefixes is a stepping stone to copying full callsigns. If you learn to copy the prefix as a whole, it will lighten the cognitive load in copying full callsigns. In my experience, learning the country that the prefix belongs to will help even more. Giving the prefix a useful meaning makes it easier to remember.

Thank you, Daniel (KK4FOS) at Buckmaster International ( https://hamcall.net/haminfo.html ) for making this possible! So how did I determine which prefixes to use? First, I identified the common DXCC entities by using the DXCC Most Wanted 2019 list, reversing it, and taking the top 50 entities. It is a reasonable assumption that the least wanted DXCC entities are the most frequently heard stations on the air. 

Next, I needed to determine which prefixes are most commonly issued by the governing body for each DXCC entity. For this, I reached out to Buckmaster International on whether I would be able to download and use their database to determine a list of callsigns for a given DXCC entity. The answer was no, but Daniel immediately provided the information I needed to figure this out. Once I had a list, it was a small matter of writing a couple of short Perl and R scripts to parse, filter, count, and combine data to get the most commonly issued prefixes for a given DXCC entity.

I limited the number of prefixes for a given DXCC entity, to at most 10. I further pruned the list so that each prefix had to be more than 10x less than the top prefix for that DXCC entity. Meaning if the top prefix had 10,000 callsigns assigned, the other prefixes within that DXCC had to have at least 1,001 callsigns assigned to it to be kept. The exception to this rule was the United States.

There is a comprehensive list of Morse code resources on my Morse Code Ninja website ( https://morsecode.ninja/practice/index.html ).

73 de AD0WE!