RDL is one of the callsigns used on a Russian Navy one-way strategic broadcast present on many HF frequencies, and also on VLF.
The network carries Morse code and T-600 data, using BFSK modulation with a shift of either 200 Hz on HF or 75 Hz on VLF. It airs the following types of messages:
- Two 5-digit groups repeated three times, e.g. RDL RDL RDL 36855 52267 36855 52267 36855 52267 K
- Longer 5-digit group messages, e.g. RDL RDL RDL 11111 97842 64537 ... 59306 18418 23077 K. The last group is the day of the month (2 digits) followed by the group count (3 digits). The first group of the message may also be "22222".
- "Monolith" type messages, typically using the callsign WEGI or RGT77, but sometimes also others, e.g. XXX XXX WEGI WEGI 80637 KABELXQIK 6622 9778 K.
- 50 Bd T-600 messages, sometimes preceded by Morse code "XXX XXX", which is the indicator for a "Monolith" type message.
The network has many transmitter sites throughout Russia, and is organized into two frequency clusters: one using 18.1 kHz as the VLF channel, and the other using 21.1 kHz. The HF simulcast lists are not exhaustive. "Monolith" type messages sent on this network tend to also be relayed by hand using plain CW on other frequencies afterwards.
|18.1||10535, 11468, 12832, 14411, 14664, 16112, 17452, 17460, 19210, 22864|