priyom.org

E25

Enigma ID E25

Spectrum image E25

Name Rebeat
Frequencies 6140, 9450. Test transmissions on 9500, 9550, 9600.
Status Active
Voice Female automated and Live Male, with Arabic accent, the last digit in the groups is inflected
Emission mode AM, USB, USB + carrier
Location Egypt

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Activity pages

Download audio sample

Known counterpart stations

Run by Egyptian intelligence (GID). First heard in 2000.

Format:

Intro Preamble Message Repeat Outro

Music
or
1 kHz tone 

780 Message 9049 4001 9210 3557 2696 7891 3585 9866 5663 9210 Rebeat 9049 4001 9210 3557 2696 7891 3585 9866 5663 9210 End of message End of transmission
  3-figure ID   4-figure single groups   4-figure single groups    
may be skipped Repeated for 1 - 3 minutes Repeated thrice   Repeated thrice      

The preamble may occasionally take form of a 3-digit group, followed by another 3-digit group, and a single digit. The first 3-digit group denotes a recipient of the full, 4-digit group message. The second 3-digit group denotes a recipient of an E25a message, defined by the following digit. Sometimes there are two 3-digit groups in the intro.

The groups in the 4-digit messages can be arranged in different formats, depending on the ID used.

These are some commonly observed formats:

  • The third and the last group are the same. Last two digits of the second group, when inverted, give the group count. First two digits of the second group, when inverted, give the serial number. (usual format)
  •  The second and the second last group are the same. Last two digits of the first group, when inverted, give the group count. First two digits of the first group, when inverted, give the serial number. (used by ID 835 and 360. Formally the format of E25b)
  • The second and the last group are the same. First 2 digits of the third group give the serial number when inverted. The other 2 digits give the group count when inverted. (used by ID 701 and 111)
  • First 2 digits of the first group give the serial number when inverted. The other 2 digits give the group count when inverted. No repeated group. (used by ID 116)
  • None of the above, none of the groups give a serial number and group count. No repeated groups (used by ID 185, 672 and 169)

The serial number increases with every new message for each ID. The serial number is reset yearly on January 1st.

The music intro used depends on the ID. For example, the ID's in the 83# range use the Umm Kulthum song "انت عمري" (Enta Omri). Another common Umm Kulthum song used as the intro is أروح لمين (Arouh Limin). Transmissions on 6140KHz don't seem to use music as intro. Allthough pieces of Enta Omri were heard on this frequency without following E25 transmission. Sometimes pieces of music can be heard after or during a transmission.

The music used from Umm Kulthum is taken from a live concert in Paris in 1967. (applause from the audience can be heard)

Scheduling

E25 uses 2 timeframes for its transmissions. From 700-1200 UTC 6140KHz is used, and from 1200-1500 UTC 9450KHz is used.

There seems to be a relation between the start time of a transmission and the ID used, transmissions using the same ID usually transmit at around the same time.

The 6140KHz slot seems to be aimed at the Middle East/Asia while the 9450KHz slot is aimed at Southern Europe.

E25 also sends daily test transmissions, These consits of a long 1KHz tone, followed by some music and then it shuts down. These transmissions are on 9400khz, 9500KHz, 9550KHz and 9600KHz around 1110z and 1210z. These may not allways transmit. They use less transmitting power than normal E25 transmissions, this means the tests are lower in strength than usual transmissions. They use different songs. Not all by Umm Kulthum.

Behind the scenes

Mistakes are quite common on E25. Ranging from Windows login/logout and error sounds leaking on air, to the complete transmission failing.

The station uses a computer running Windows 7 with a soundcard to send the numbers (prior to February 2016 Windows XP was used), it used the Cityscape soundpack on Windows 7 from February to June 2016, judging by the sounds leaked on air (see 2016 logs). Nowadays it seems that the soundpack has been changed to the Nature pack.

The station seems to use the same transmitter site as Radio Cairo. As a test transmission was heard using the same transmitter problems as Radio Cairo. ( see N&O Newsletter 222 )

The station is known to have at least 2 transmitters. One main AM transmitter used for regular transmissions, and one SSB transmitter set in USB mode. The SSB transmitter is only used for backup.

E25 seems to be using a hotswitch method for changing frequencies. The default frequency of the transmitter appears to be 6140KHz. Sometimes when a transmission is made on 9450KHz, a carrier is noted on 6140KHz, then it switches to 9450KHz.

The program that runs on the PC is known for crashing often. Sometimes the PC can be heard restarting mid transmission, or there is a long pause which may indicate the program crashed, since Windows 7 error sounds can be heard.

Sometimes the operator can be heard playing solitaire.

History

Up to 2007 E25 used live male and female operators, after 2007 they switched to using a computer running Windows 98 to handle the transmissions. (source)

In October 2007 2 transmissions were heard using a live female voice, which is similar to the current automated one. ( source)

Also up to 2007, there was a variant designated E25b. This variant sent the callup in english and the message in arabic. A live male voice was used for this.

From 2008-2010 Windows 98 was used for transmissions, in 2011 they switched to Windows XP. ( source)

From late 2010 E25 started using a faster speed with the numbers.

In February 2016 they switched to Windows 7, before that Windows XP was used.

In January and June of 2016 the station was observed with a live male voice, similar to the one used before they started using the automated voice. Two transmissions were made in USB while a third one used full AM. (see 2016 logs)

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