Thursday, April 05, 2007

Cuban PSK Tries New Mode (PSK220F)

On April 5, the 1600 and 1700 UTC schedules of the new Cuban numbers using phase-shift keying gave us yet another surprise. The transmissions were in a relatively unknown mode named PSK220F, not the more normal PSK31 used by amateurs. The main difference is that PSK220F is much faster. As a result, the transmission was in both ordinary numbers and the "cut" numbers where letters are substituted.

The frequency used at 1600 UTC was 17478.0 kHz, and at 1700 UTC it was 17436.0 kHz.

A brief transmission in computer generated voice using the normal V2 mode preceded these PSK220F skeds, as if to let receiving stations know that something new was going to happen. Perhaps this other callup was a coded announcement.

Most amateur freeware does not decode PSK220F. One that I know does is the latest version (4.2) of MultiPSK. This is an amazing program for free. Don't let the old-school user interface fool you. It does a creditable job on a huge number of modes, with only a few of its advanced features disabled until it's paid for. MultiPSK is available at a couple of sites. The main site is F6CTE, with a US mirror at N8KBR, and UK here.