This site is for and about amateur (ham) radio. This is my way of giving back to the ham community.
This site was an idea born out of frustration in picking a vanity call sign. When I got my Amateur Extra ticket I decided to change my call sign. My original call sign was KM4UUB and I really didn't like it. The "UU" just didn't come across the air cleanly. Besides, I just got my Extra and that opened up all the reserved call signs for the Extra class!
Finding a new call sign that I would want turned out to be harder than I thought. First, I had to decide did I want a highly coveted 1x2 or 2x1 call sign? Problem is they are all taken but a few come open every month. Or do I want a longer call sign with my name or initials. Maybe some cute call sign that spells something.
I decided to try to get one of those prized call signs but as a back up would keep thinking about a longer call sign that was personalized for me. I tried to think of some call signs I would like but didn't really know what I wanted. Was there some way to search all the available call signs? There were several sites that had search tools but they only searched for available call signs that were actually listed in the FCC database. If they didn't list a call sign then you had to do a two-step and go search the FCC database to see if was assigned.
The "problem" with searching the FCC database is that it only lists the call signs that have actually been assigned at some time in the past! If it hasn't been assigned at all (or maybe assigned quite a while ago) then there is no listing. I determined (later) that that there are almost 9 million possible call signs but only about 800,000 currently active hams. In addition there were about 500,000 call signs listed that were either canceled, expired or terminated. It was just in these 500,000 call signs that other sites were searching for availability.
There are about 7.5 million available call signs not listed in the FCC database!
Searching for a suitable call sign in the FCC database is painful. It has limited wildcard functionality and it only returns call signs that are assigned. Trying to pick through the results for potentially available call signs between the returned assigned call signs is tedious. Another problem is that you have no easy way on knowing if the available call sign is in fact a valid call sign! There are a number of call signs reserved for various reasons. Digging through all the rules and exceptions can be painful.
So how could I improve searching for all the available call signs that are available? First, I had to build a database of all the possible call signs. In addition I had to include extra information about each call sign that contained additional data to allow filtering the call signs for different regions, classes, configuration and other special rules. I then built a web page that allowed the user to select the filter parameters and supply a search pattern (a simple form of regular expressions) that allowed the user great flexibility to hone in on a set of interesting call signs.
I grab the FCC database using their nightly feeds and apply the status of each call sign to my list of every call sign. The nightly feeds consist of one weekly full database dump (Sunday night / Monday morning) and the other 6 days are incremental feeds of just the changes for that day. It is from this data I derive all the numbers for the call signs by status.
Dale - KJ4C