U beacon 7830.4 kHz

Waterfall capture of mysterious single-letter beacon "U" on 7830.4 kHz CW, on 2018-10-12 at 2221 UTC (2018-10-13, 01:21 local date/time).

Dave Wright, K3DCW, discovered that the "U beacon" is actually a malfunctioning FSK transmission from the US Navy transmit site in Puerto Rico, centered on 7830kHz.

(20181012-2221-7380 4--U beacon.png)