This was shared on the Yankee Clipper Contest Club email list on May 26, 2021, by Ray Conrad NM2O. Reprinted here with his permission.
There are 930 possible USA Prefixes, that’s for continental and offshore. Some like KP1 or KP5 are not active now. The rarest are in Alaska where there is only one WL2 and two WL3 calls. If we back out about 48 offshore prefixes, it’s about 880 in the lower 48. Someone with WPX honor roll might know if a prefix like NP1 or WP1 was ever issued.
In most districts, there are at least 22 calls assigned in each prefix where it’s mostly 2×1.
Some prefixes have thousands of calls where it can have 2×1, 2×2 and 2×3. KA1 has 5204 hits.
There is turnover, many times a 2×1 is turned in for a 1×2. The AE7Q site shows the available calls and application status.
QRZ allows searching with an *. So, AA1* shows that there are 664 hits. The “alias match” shows previous calls. For example, W1CLW turned in AA1XH. So, the exact number would need to be determined from the current FCC database.
The following is the continental USA prefixes worked by TI7W last year in WPX CW 2020. He had 436 USA out of his total of 1135 prefixes. (AH2 is an exception, he doesn’t sign “portable.”)
Here’s the list as tabulated by the SH5 analysis program.
Formatting the results as a table allows the holes to be seen. Can you borrow a call and fill in a slot?
AA0 AA1 AA2 AA3 AA4 AA5 AA6 AA7 AA8 AA9 AB0 AB1 AB2 AB3 AB4 AB7 AB9 AC0 AC1 AC5 AC6 AC7 AC9 AD0 AD1 AD3 AD4 AD5 AD6 AD7 AD8 AD9 AE0 AE1 AE2 AE3 AE4 AE5 AE6 AF3 AF4 AF5 AF6 AF7 AF8 AG3 AG6 AG9 AH2 AI1 AI2 AI4 AI9 AJ1 AJ3 AJ6 AJ8 AJ9 AK1 AK2 AK6 AK9 K0 K1 K2 K3 K4 K5 K6 K7 K8 K9 KA0 KA1 KA2 KA3 KA4 KA5 KA6 KA8 KA9 KB1 KB2 KB3 KB4 KB5 KB6 KB7 KB8 KB9 KC2 KC3 KC4 KC5 KC7 KC8 KC9 KD0 KD2 KD3 KD4 KD5 KD6 KD7 KD8 KE0 KE1 KE2 KE3 KE4 KE5 KE6 KE9 KF2 KF3 KF5 KF7 KG0 KG1 KG3 KG4 KG5 KG6 KG7 KG9 KI0 KI4 KI5 KI6 KI7 KI8 KJ0 KJ4 KJ5 KJ6 KK3 KK4 KK5 KK7 KK9 KM0 KM1 KM3 KM4 KM5 KM6 KM7 KM9 KN0 KN1 KN4 KN5 KN6 KN7 KO3 KO4 KO6 KO8 KQ1 KQ4 KQ5 KR2 KR4 KR6 KR7 KR8 KS0 KS2 KS3 KS4 KS7 KS9 KT0 KT1 KT3 KT4 KT5 KT6 KT7 KT8 KT9 KU0 KU1 KU2 KU6 KU7 KU8 KU9 KV0 KV2 KV3 KV6 KV8 KW0 KW1 KW4 KW7 KX0 KX1 KX2 KX7 KX9 KY0 KY2 KY6 KY7 KZ1 KZ5 KZ7 KZ8 KZ9 N0 N1 N2 N3 N4 N5 N6 N7 N8 N9 NA3 NA4 NA5 NA6 NA8 NA9 NB1 NB3 NB4 NB6 NC1 NC3 NC6 NC7 NC8 ND2 ND3 ND4 ND7 ND9 NE0 NE1 NE3 NE4 NE5 NE6 NE7 NE8 NE9 NF4 NF5 NF6 NF8 NG1 NG3 NG6 NG7 NI0 NI1 NI7 NJ1 NJ2 NJ3 NJ6 NJ8 NK4 NK5 NK6 NK8 NK9 NM1 NM4 NM5 NM6 NM8 NN1 NN2 NN3 NN4 NN5 NN6 NN7 NO3 NO6 NQ2 NQ5 NQ9 NR0 NR1 NR3 NR4 NR5 NR6 NR7 NS2 NS4 NS8 NS9 NT0 NT5 NT6 NT7 NU4 NU5 NU6 NU7 NV8 NW1 NW2 NW3 NW6 NW7 NX0 NX3 NX4 NX6 NX8 NY3 NY4 NY6 NY7 NY8 NZ2 NZ4 NZ6 NZ7 W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 WA0 WA1 WA2 WA3 WA4 WA5 WA6 WA7 WA8 WA9 WB0 WB2 WB4 WB5 WB6 WB7 WB8 WB9 WC0 WC3 WC5 WC6 WC7 WD0 WD8 WD9 WE0 WE2 WE5 WE6 WE8 WE9 WF3 WF7 WF9 WG3 WG5 WG9 WI6 WI7 WJ1 WJ2 WJ4 WJ5 WJ9 WK0 WK1 WK2 WK4 WK5 WK6 WK7 WM3 WM9 WN1 WN2 WN3 WN4 WN6 WN7 WO1 WO2 WO3 WO4 WO6 WO7 WQ5 WQ6 WR1 WR2 WR3 WR4 WR7 WS3 WS4 WS6 WS7 WS9 WT2 WT8 WT9 WU6 WU9 WV4 WV7 WW1 WW2 WW4 WW5 WX3 WX5 WX6 WX8 WY3 WY8 WZ7 WZ8