How I Chose My New Call Sign

After nearly 28 years as W8MHB, I decided recently to apply for a new vanity call sign. Some would say I was crazy for doing so. I thought so myself at times. But I’m at a point in my life where I’m ready to embrace some changes. Besides, nothing is really permanent.

So on July 10th, 2025, I submitted an application for a new vanity call sign. I paid my $35 to the FCC and waited. After three weeks or so, on July 29th, my new grant became official. I am now licensed as AI5MX. Here’s how I arrived at my choice.

Choosing a new call sign turned out to be more “art” than “science,” although I did have a few objective criteria that I tried to stick with:

1. Must be a Group A call sign—limiting to 1×2s, 2×1s, and 2×2s that start with A

2. Must be good on CW. This includes a number of factors:

   • Must have a lower Morse weight than that of W8MHB, preferably by at least 10 points—effectively, new weight of 52 or less
   • Must sound good on CW
   • Must not end in meaningful combinations like “CQ” “K” or “BT”

3. Must sound good on voice. Not so much phonetically, but when the letters are spoken.

4. Should, if possible, not have been previously issued

5. Must not have a “W” prefix

6. Must have a call area digit in Morse that is shorter (i.e fewer dahs) than 8—effectively limiting the pool 3, 4, 5, 6, and 7.

7. Must have a one-syllable call area digit—further limiting the pool to 3, 5, and 6. ^[1]

Those criteria limited my choices, but there was still a lot to work with. I dismissed the 1×2s and 2×1s pretty early on, as I didn’t want to deal with all the competition (and likely disappointment) associated with chasing those calls. More importantly, I wanted to try to satisfy my (4th) requirement for a previously unused call sign. That left me with the 2×2s, which is a limited set to begin with—specifically, AA–AG and AI–AK. ^[2]

I ruled out a lot of prefixes right away because they just sound terrible when spoken out loud—AA, AE, and a few others. I ultimately landed on AI. ^[3]

I then started looking at two-letter suffixes. Right away, I ruled out letters that are long in Morse, like Q, Y, and J. I ruled out some letters in the last position, most notably K. I ruled out E and T. ^[4] I kept trying combinations and testing them in both Morse and voice until I came up with some that I liked. MX rose to the top of the list pretty quickly. It’s not the best for Morse, but it’s okay and it sounds really good in voice.

Finally, I put the prefix and suffix together with the acceptable call area digits to see what was available. In the end, the only contenders were AI5MX (my first choice) and AI3MX and those were the two I applied for.

In the end, I was successful in satisfying all of my requirements:

1. Group A call sign: Purists would say that a 2×2 of any kind is not a “real” Extra class call sign, but I don’t care.

2. Good on Morse: AI5MX has a Morse weight of 50. I don't exactly love the all-dits “I5” followed by the dah-heavy “MX” but it’s a compromise.

3. Good on voice: With only five syllables, it beats “W8MHB” by two. But more importantly, I like how it sounds.

4. Previously unissued: Partial credit here since AI5MX was first issued in 2016. The previous grantee only had it for a few months before trading it in for vanity call, so I can live with that.

5. No W: I associate W call signs with a golden age of amateur radio so I have a great fondness for them. The reality is that this association is all in my head. Either way, I had the privilege of using a W call for 28 years and now I’m ready for a change.

6. Shorter call area digit: I have a real love-hate relationship with the eighth call area. I’ve called “8-land” home for 54 years and it’s a little strange not having an 8 call. But it’s sort of clunky in CW and doesn’t exactly roll off the tongue. 5 works for me, even though I never have, and probably never will, live in 5-land. ^[5]

7. One-syllable digit: I like 7 in CW but it’s like a vocal speed bump. That’s really the driver here. If AI6MX had been available, I might have requested it as my first choice, but I kinda think 5 sounds better.

So that’s how I got here. Now I need to update my logging software, and my LOTW certificate, and a raft of logins and who knows what else. But it’ll be fun. Thanks for reading. Hope to see you down the log. 73.