Modes CCIR493-4 being used again

[ka3jjz]

Anyone that has been watching the UDXF logs has noted a very large increase in the use of CCIR493-4 (also known as CODAN selcall); this is a digital selcall mode that is evidently used in the maritime service. It seems that the activity in the South China Sea with the Chinese building artificial islands and bases. There has been an upswing in interest in finding new frequencies and looking at the selcalls. The SigIDWiki has a page on this mode, along with compatible software. Note that the free Rivet decoder as well as Sorcerer is listed as being compatible, so it's not necessary to get the multi-kilobuck packages for this. Here's the link...

CCIR 493-4 Selcall - Signal Identification Wiki

This is a good example of world events causing old modes to become active again....Mike

 

[ka3jjz]

From the April UDXF logs, here is a list of frequencies heard. Notice how many of them intrude into the 40 meter ham band, in violation of several ITU regulations

7106, 7109, 7112, 7121, 7124, 7130, 7133, 7142, 7157, 7160, 7936, 8003, 8006, 8009, 8012, 8015, 8019, 8021, 8024, 8027, 8030,
8033, 8036, 8041, 11163

Mike