Friday, November 13, 2009

Confused by all of the new digital modes when hearing them??

If you have been the HF band lately listening in the digital portions, you will know that there are some very strange noises there. Some are more well known like the inviting sounds of CW, or the sweet double tones of PSK31. Others, like the difference flavors of RTTY or the numerous alphabet-soup of OLIVIA modes are harder to identify by ear alone. Just when it seems darkest, there is a solution right there on the programs you are already probably using.
- The solution is RSID

The Reed-Solomon ID (RSID) is a short 16-tone MFSK transmission which identifies the mode in use. The RSID transmission is about 180Hz wide and lasts for just less than two seconds. -- Reed-Solomon IDs - This idea was originally developed by Patrick Lindecker /f6CTE. -- You should enable RSID when using an 'exotic' mode such as Olivia so that users of programs with RSID support know what mode you are using. Your digital decoder program will then reconfigure itself to support that mode, not everybody uses this yet, but at least, now you know.

There are two ways to enable RSID (DM780 + FLdigi):
  1.   In Program Options select Modes + Ids and check the option to show the RSID button in the transmit toolbar,
  2. Add the tag anywhere in the text being sent.

73 de ki4SGU


  1. Seems a neat idea but at 180Hz wide it should not be used to identify modes that are narrower than that or it would cause QRM.

  2. I would agree, albeit only very very breifly.. I think where it seems to make most sense are the Olivias which are all 250+ wide.