Talk:Multiple frequency-shift keying

From Wikipedia, the free encyclopedia

	This article is within the scope of WikiProject Amateur radio, which collaborates on articles related to amateur radio technology, organizations, and activities. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion.
Start	This article has been rated as Start-class on the quality scale.
Mid	This article has been rated as Mid-importance on the importance scale.

[edit] Copyright issue

I've got a problem with the image shown in this article : I found it on http://www.qsl.net/zl1bpu/MFSK/ with a copyright. Perhaps this image is copyright violation ?Flying jacket 11:54, 30 March 2007 (UTC)

[edit] Is DTMF a kind of MFSK?

My understanding is that DTMF is *not* a kind of MFSK. The MFSK used by ham radio operators[1] always transmits one tone at a time. DTMF transmits 2 tones simultaneously. So ... should we clarify in the article that DTMF is *not* a kind of MFSK ? Or have I misunderstood what MFSK is ? What is the technical term for "kinds of modulation that use 2 or more simultaneous tones, including DTMF and COFDM"? --75.19.73.101 (talk) 08:31, 13 December 2007 (UTC)

I believe the proper designation for DTMF and ICAO SelCal is either F2DE or A2DE, depending on the basic modulation, FM or AM. Per ITU rules described in Types of radio emissions:

2 is for One channel containing digital information, using a subcarrier

D is for Telecommand

E is for Multi-condition code, one condition per "signal element"

Sv1xv (talk) 11:57, 7 January 2008 (UTC)