XP was in use from 1993 - 2005. It has a 1 baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. intro, which includes a 3-digit ID and the number of messages to be sent, and then two tones at 7.5Bd alternating 20 times, before the 5-digit numeric groups begin to send at 7.5Bd. Just like XPA, there is a distinct sync tone at the lowest tone of the MFSKMultiple Frequency Shift-Keying signal, repeated every 5 MFSKMultiple Frequency Shift-Keying tones, which denotes a space. At the end of the transmission, 319Hz and 511Hz tones alternate 20 times, denoting the end of the transmission. The bandwidth of the AMAmplitude Modulation signal was about 1200Hz, but the individual sideband bandwidth was around 250Hz.
XP also had some variants, XPH, XPM, and XPL. XPH used higher tones, where XPM uses mid tones, and XPL using low tones. The most common recordings found were on XPH, with very little on XPM and XPL.
Full Transmission Recordings
The Conet Project: XPH
XPH - 1998-July-10-0619utc-11040khz
- Professional Equipment/Software
- Wavecom W-Code
- Wavecom W-Spectra
- WAVECOM Database: SP-14
- shoc Database: SP-14
- Priyom XP Information
- numbers-stations.com XP
- Number Oddities: Number Station Sound Samples