4XZ – IDF Navy

4XZ is a Morse station run by the Israeli Defense Force (IDF) Navy in Haifa. It repeatedly sends VVV DE 4XZ 4XZ = = when it’s not actively sending messages.  It simultaneously broadcasts 24/7 on multiple frequencies 2680, 4331, and 6607 kHz.  Sometimes it can be found on others.

Message Format

Each section of the message begins with the recipients callsign (letter, letter, digit, letter), the message number, a 2-letter ID which uses are unknown, and then the group count. All digit sequences in 4xz are written in reverse order since Hebrew is read from right to left.

One message can be addressed to more than on call sign. In this case, call signs are separated by commas. Another way it sends messages to multiple call signs is writing the first call sign, then “L-“, and the next call sign. The purpose of these two different formats are unknown.

4xz occasionally sends service messages. There are two types of these:
Delete messages: HL9Q NR 723 TO NR 133 QQL (the call sign used in those typically does not receive 5 letter groups)
Confirm reception: AM0B QSL NR 13

Idle Recording Sample



Until July 2005 4XZ used to operate with two independent broadcasts.

The 4XZ Schedule from 2001 – 2005 was:
Broadcast 1: 2800//4241//5159//8103//10046//12984 kHz
Broadcast 2: 2680//4331//6379 kHz

4XZ used to have the ENIGMA ID M22, but it was withdrawn since it’s a military station.

Significant Observations

January 2006:

Weather Bulletins and Morse messages in Hebrew Morse Code are not disseminated any longer.

Spring 2011:

The MOSSAD Number Station E10, after dekades of uninterrupted operation, ceased to exist. There was no impact on 4XZ operation.

January 2012:

Additional frequencies came in use, but this time they did not vanish after a few days. 2680 kHz
4331, 4595 kHz
6379, 6607 kHz

April 2012:

Again more frequencies are heard in parallel on several or all of the following frequencies:
2680, 2833 kHz
4331, 4539, 4595 kHz
6379, 6525, 6607 kHz

December 2012:

These following frequencies are regularly on the air:
2680, 2860 kHz
4331, 4595 kHz
6379, 6607 kHz
5000 kHz was temporarely used around December 8th

Station Summary

Activity: Active
Emission Mode: Morse – CW, MCW
Location: Haifa, Israel
Frequencies: Broadcasts simultaneously on 2680, 4331, and 6607 kHz



Fascinating Shortwaves Israeli Morse Station 4XZ Article (archived)
Priyom 4XZ Profile (Deleted)