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View Full Version : Local 26 MHz DRM Skywave Analysis


Zalm
14-10-2007, 00:06
A brief paper by H. Donald Messer on 26 MHz propagation and interference has been posted at:

http://www.26mhz.us

MikeB
14-10-2007, 11:51
A brief paper by H. Donald Messer on 26 MHz propagation and interference has been posted at:

http://www.26mhz.us

On my first reading seems to just consider F layer propragation and ignore Sporadic E which is the problem with 26 Mhz most people seem to cite.

From Local Radio in the 26 Mhz band using DRM: Results of the Nuremberg Field Trial and General Considerations:

Due to the propagation conditions in the 26 MHz frequency range attention must be paid to the fact that even when low transmitter powers are used co-channel interference will be frequent both during the time of the sunspot maximum and in summer when sporadic E layer propagation will frequently occur. Therefore either the reliability of services will be limited or only one channel will be available in each region of about 400 km in diameter.
http://www.fh-nuernberg.de/fileadmin/Pressestelle/pdf/Lauterbach_Nr_31_fertig.pdf

Sporadic E can cause quite low powered signals to be received very strongly thousands of kilometres away so skywave limiting antennas wouldn't necessarily be effective in preventing it.