Priyom.org

XPA2

Priyom ID		Spectrum image
Enigma ID	XPA2
Name:	Polytones
Frequencies:	Various
Status	Active (daily)
Enigma ID status	Assigned
Voice	N/A
Emission mode	J1D (digital USB)
Location	around Moscow, Russia
Activity pages	2011	No audio sample available yet
Enigma 2000 Control list description	First heard 3 May 2006, ceased 2 June 2006 then re-appeared  Dec 06 See NL 35 July 2006 for full initial report.[P36 to 39] Narrow bandwidth, 15Hz tonal separation.  Operates at 3 differing speeds and can be mistaken for another system, it is essential to confirm tonal values.   The construction of the tonal sequences clearly indicate this is another system designed for automated reception however the limited samples preclude, for the time being, the establishment of possible tonal secondary functions. However the nature of the transmissions together with the wide range of frequencies used  lead us to believe that this is probably of a "diplomatic" nature
Known counterpart stations
Family	XP

Overall

This is another MFSK data system with Russian origin. It's similar to XPA but has few differences:

• Lower baud rate (XPA - 10 bd; XPA2 - 7.69 bd)
• Does not include ID nor message count; immediately after intro it goes into synchronisation tones (6262626) and start+repeat tone sequence.
• No synchronisation block (again 6262626) every 64 groups
• Intro tones are inverted (in XPA longer intro tone is higher, in XPA2 - lower)

Tone analysis

Result of the tone investigation made by danix111 in June 2011 is:

Tone (Hz)	Function	Secondary function(s)	Notes
995	Space	Low intro tone/start pulse	-
1035	Start tone	-	Follows repeat tone (1075) before start pulse (995)
1055	End tone	-	Follows fig 0 after message
1075	Repeat	Start tone	Follows character to repeat Used with start tone before transmission start tone
1085	Fig 0	End tone	Used with end tone after message
1105	Fig 1	-	-
1135	Fig 2	Sync segment	6262626 synchronisation tones
1145	Fig 3	-	-
1155	Fig 4	-	-
1165	Fig 5	-	-
1175	Fig 6	Sync segment	6262626 synchronisation tones
1205	Fig 7	-	-
1225	Fig 8	-	-
1235	Fig 9	High intro tone	-

Please keep in mind that those tone values are different on different receivers.

Transmissions

Each transmission starts with two-tone intro, lower and longer tone is space tone (995 Hz), meanwhile higher and shorter one is fig 9 (1235 Hz). It's exactly 2 minutes long.

Immediately after it 7-tone synchronisation segment follows: 6262626. Latter part consists of alternating repeat (1075 Hz) and start tones (1035 Hz), both repeated 10 times. After both parts long start pulse follows, which is also 995 Hz.

Messages are 5 figure groups. First 3 groups are, paded with zeroes in the beginning when needed:

• 3- or 4-figure serial number
• Group count (always excludes serial number, group count and decode key)
• 5-figure decode key

Regarding decode keys, they depend on a schedule. The most of them currently reported are usually starting with 1 or 7. There seems to be relation between them that needs analysis.

The rest of message is obvious - encrypted content. Everything ends with alternating fig 0 (1085 Hz) and end (1055 Hz) tones, also repeated 10 times. After them transmission is done.

Null messages take format 0xxxx 00001 00000 10140.

If next message is going to be broadcasted, 00000 00000 part appears then 2nd message follows.

Schedules

XPA2 is very active, changing schedules all the time. Usual for them is 10 minute delay between repeats. Some got 20 minute delay, they are believed to contain transmissions longer than 9 minutes that can occur sent when needed. Some schedules are reported regularly every month, some can go one month then just vanish from the air.

Known regular XPA2 schedules include (up to date frequencies are given in Priyom.org's 2011 schedule):

Tuesday, Thursday - 19:30/19:50/20:10
Tuesday, Sunday - 21:00/21:20/21:40
Thursday, Friday - 22:00/22:10/22:20

XPA2 is still on search, not all schedules are known.

Location

Enigma 2000 has triangulated XPA2 and it's reportedly located south of Moscow.

 

2011 Activity