Thanks Sholto, going to give it a try Andy
On Mon, Aug 9, 2010 at 6:38 PM, sholtofish <sho...@probikekit.com> wrote: > > > Interesting new software from Con.... > > New narrow-band mode for LF/MF released > > Con Wassilieff ZL2AFP has recently released a new narrow-band digital mode, > CMSK, designed specifically for the LF and MF ham radio bands (2200, 600 and > 160m). > > The mode uses MSK modulation, familiar to LF and MF listeners as the mode > most used by commercial and military transmissions. One major advantage of > MSK is that unlike PSK, it does not require linear amplification to maintain > narrow bandwidth. > > The new ZL2AFP CMSK mode can be described as Correlated, Convolved Minimum > Shift Keying, and uses a full-time NASA standard convolutional coder with a > generous interleaver to provide impressive QRN resistance. > > Synchronism is assured, even on very weak signals, by a transmitted > PN-sequence frame marker and cross-correlator at the receiver. > > Four modes have been provided, from 125 baud (<200Hz bandwidth, 60 WPM) > down to 7.8 baud (12.5Hz bandwidth, 4WPM). The narrowest and slowest mode is > intended for beacon applications, and can be received 100% at -21dB S/N in > 3kHz bandwidth. The default mode, CMSK63, has been reliably copied across > the Tasman, at a range of 2200km on 600m from a transmission well under 1W > EIRP. > > Software for this new mode is now available from > www.qsl.net/zl1bpu/CMSK/cmsk.htm, where a description of the design is > also given. > > Murray Greenman ZL1BPU/ZL1EE > > >
