G4
STATUS- INACTIVE  
G4  3-note Oddity Version 1 
G4  3-note Oddity Version 2 
Note from Bill in Ohio, USA about the possible origin of the 3 tones:
 "The three notes of the Three Note Oddity sound very similar to the so-called "SIT tones" heard at the beginning of recorded telephone intercept messages. The pitches are somewhat lower but it's very similar, right down to the slight flatness of the top note. I don't know if they use SIT tones outside of the US, so I've included a recording of an intercept message with the tones. Try slowing this clip down to 4000 Hz (half speed) and listen to those three tones at the beginning of the message, and you'll see what I mean." Sorry

Hear this piece of music composed by Jimmy in Oxford, comprising of G4 and G7 samples. 3-Note (plays in Winamp)

Another piece composed by William J. Spiropoulos base on 3 note oddity.

THREE NOTE ODDITY

Courtesy ENIGMA Group.

A Very Odd Pair-Family XII

This family contains two members, M29 (VDE) which has two variants M29A and M29B and G4, it’s German language arm. The Morse arm operated several schedules, daily, twice weekly, or weekly. Both M29 and G4 change their frequencies monthly and starting times vary an hour between summer and winter. M29, whose schedules are most likely to change (as there are more of them), may begin at five-minute interval within the hour, but generally prefer h+00 and h+30. G4 generally only operates one schedule, although others occasionally appear for short periods.

VDE-Canadians in Hungary?

The only Morse format in use at present in M29A, which is more complex than the voice format. Unlike G4, it uses the bogus callsign “VDE” officially allocated to Canada. Like so much about this station, the reason for this is unknown and lies back in the mists of time, for this family was already around during Cold War days.

The call consists of VVV VVV DE VDE VDE VDE sent repeatedly for five minutes at average speed. This is followed by the preamble- a pause, more VDEs another pause and a two-figure group repeated once (purpose unknown). A second two figure group, also repeated once, follows-this is the Group Count which is always between 10 and 40-usually in the 20s. After this comes a date of month group (a single or double figure repeated once 1-31 referring to date of first transmission of message) and a four-figure time group (repeated once). This last group refers to the time in UTC of the first sending of the message and would usually end in either 00 or 30.

After a short pause the message follows consisting of paired five figure groups, nearly always of a unique non-random nature. This string of groups ends with AR (end of work). Repeats are sent 30 minutes later on a frequency 2100 kHz higher or lower depending on time of day.

 A further pair of repeats may be sent later in the day. Short zeroes are used and the transmission mode is basic i.c.w. Messages are changed on a weekly or monthly basis.

Achtung G4 Calling

G4 transmissions start at any five-minute interval within the hour with a repeated sequence of three rising electronic notes. This continues for five minutes when, after a pause, a woman’s voice shouts as if on a parade ground. “Achtung, Achtung”, after which the message follows in paired non-random five-figure groups, before ending with “Ende, Ende”. Another  “Achtung, Achtung” and the message, (with “Ende, Ende”) is repeated. Note the complete lack of preamble, lack of call sign and the repeat-unlike M29.

G4’s long-term regular Sunday schedule has been with us for many years with two transmissions: 2005 and 2035 UTC. These are now repeated every Thursday-same time and frequencies. As with M29, the 2035 repeat is sent 100 kHz higher. The frequencies change monthly along with the messages, which have always been repeated throughout the calendar month, but recently there have been a few cases of two messages per month. Such an increase in traffic has never been known before.

Like M29, the same unique non-random message groups have been used for many years, but again quite recently, there have been transmissions where random groups have been sent throughout messages.

Like everything about this station, known as the Three Note Oddity, frequency usage is peculiar. A notable feature is its complete disregard for ITU frequency allocations (and call sign regulations). The family has used any frequency between 3130and 8752 kHz and its repeats half an hour later always stick to the 100 kHz rule, regardless of who may already be using the frequency.

There is no easy way to predict the regular frequency changes, but long term monitoring has produced patterns. For example, G4 Sunday/Thursday schedules has operated as follows: As a month in one year may use the same frequencies in the same month of the next year, but this pattern doesn’t continue year after year. Sometimes, due to the inflexible frequency use pattern, there may be other strong transmissions sharing the same channel and G4 may be swamped, usually however, the signal is very good in this country.

Due to the non-random nature of nearly all of the messages, the particular form of encryption used means that the messages are not sending text, i.e. sentences made up of words. All other number stations which send messages in blocks of groups are sending text, but this family in unique in this respect. Random groups only stared to appear this year. Here’s an example of the non-random structure G4 SEP 98

23 Groups

32587 05458 32125 45214 65212 85458 65458 65458 54120 45120 45200 45158 65425 54214 74548 35458 62102 85402 78521 84522 14520 87458 32125

Total number of figures: 23 x 5 = 115
Mean individual figure count, if random 11.5
Actual figure count 0=7 1=10 2=20 3=4 5=29 6=5 7=4 8=13 9=0
Note there is no 9s at all.
Paired figures one only 00. Average would be about 23.
Repeated groups 32125 (x2, a popular group at this time, one message contained about five) 65458 adjacent.
Anagrams: 45214/54214  45210/54120/14520
1st two figures 45(x4) 65(x4) 32 (x4) 85 (x2) 43 (x2)
Last Two 58 (x7) 25 (x3) 14 (x2) 02 (x2)
2nd and 3rd 54 (x7) 52 (x4) 45 (x3) 21 (x3)
3rd and 4th 45 (x6) 21 (x3) 12 (x3) 52 (x3)
Much more analysis can be done on this message, but his is enough to show the non-randomness of the encryption.

This family is believed to originate from the transmitters at a site just outside of Budapest. Its frequencies indicate its operations are restricted to Europe and are routine and generally very stable. Use of German by G4 probably indicates that its target country is Germany (less likely tan directing German-speaking agents/illegals elsewhere. M29A is obviously aimed at trained Morse operators somewhere in Europe; the biggest mystery is the continuing of these operations unchanged since the height of the Cold War. Interestingly, the distinctive voice is the same as used by the now extinct G3, East German gongs/chimes station. 

3-NOTE ODDITY (G4) Frequency List  Thanks to: H. F. Dumrese
Summer 2005 2035
Winter    2105 2135
 ----------------
 01/95 3227 3127
 02/95 3409 3309
 03/95 3419 3319
 04/95 4581 4481
 05/95
 06/95 5281 5181
 07/95 5422 5322
 08/95 5233 5133
 09/95 4484 4384
10/95 3389 3289
11/95 3176 3076
12/95 3199 3099
 01/96 3227 3127
 02/96 3409 3309
 03/96 3419 3319
 04/96 4581 4481
 05/96 4165 4065
 06/96 4340 4240
 07/96 3935 3835
 08/96 4165 4065
 09/96 3930 3830
 10/96 3280 3180
 11/96 3270 3170
 12/96 3285 3185
 01/97 3230 3130
 02/97 3245 3145
 03/97 3275 3175
 04/97 3936 3836
 05/97 4245 4145
 06/97 4376 4276
 07/97 3930 3830
 08/97 3935 3835
 09/97 3915 3815
 10/97 3315 3215
 11/97 3265 3165
 12/97 3255 3155
 01/98 3255 3155
 02/98 3265 3165
 03/98 4435 4335
 04/98 4745 4645
 05/98 5410 5310
 06/98 5730 5630
 07/98 5840 5740
 08/98 5755 5655
 09/98 5310 5210
 10/98 4685 4585
 11/98 3940 3840
 12/98 3380 3280
 01/99 3415 3315
 02/99 3905 3805
 03/99 4520 4420
 04/99 5310 5210
 05/99 5570 5470
 06/99 5720 5620
 07/99 5680 5580
 08/99 5730 5630
 09/99 5320 5220
10/99 5320 5220
11/99 3910 3810
12/99 3360 3260
01/00 3440 3340
02/00 3920 3820
03/00 4520 4420
04/00  5210 5310  2nd transm. +100 kHz 
05/00  4830 4930
06/00  5220 5320
07/00  5360 5460
08/00  5320 5420
09/00 4760/4860
10/00 4580/4680
11/00 4270 4380
12/00 4110 4210
01/01 4120 4220
02/01 4280 4380
03/01 4750 4850 
04/01 5210 5310 
05/01 4830 4930 
06/01 NOT NOTED

Latest news:

 G04 4852kHz  2135z  07/03[84821...]YL AM S9+10dB in South London, Great
Britain. Full identification, Three notes heard at beginning then "Achtung,
Achtung, 84821" etc. Message continued until 2148z.