Thanks for these references on magnetospheric ducting. Looks like as good an explanation as any I've seen (and better than most).
Art Delibert, KB3FJO ________________________________ From: Topband <[email protected]> on behalf of Andy Cook <[email protected]> Sent: Monday, February 6, 2017 7:20 AM To: [email protected] Subject: Topband: Fwd: Echo on 160m yesterday morning I think you'll find this was Magnetospheric Ducting. Take a look at some of the articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. LA3ZA Radio & Electronics<http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation> la3za.blogspot.co.uk Radio amateur, ham radio blog ad hi - folk.uio.no<http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf> folk.uio.no There are some instrumentation prob- lems when using ham transceivers as "radar" sets. Transmitlreceive switching may not be fast enough, and our newer rigs Delay depends on your latitude - but couple of hundred millseconds is about right and this is a peak time of year for the effect. I've heard this quite frequently on 80m around mid local-evening during the winter, and one occasion - on 3rd Feb last year - very strongly indeed. That night I was able to hear my echoes with just 25mW into a dipole on 80m - but it's often strong enough to be audible with a few watts. I've read papers which suggested it does also occur on 160m. Reports of these being less strong / gone when you switch to a vertical look plausible as well since they apear to require vertical incidence from the ionosphere. 73, Andy, G4PIQ _________________ Topband Reflector Archives - http://www.contesting.com/_topband Topband Archives - Contesting Online Home<http://www.contesting.com/_topband> www.contesting.com Topband Mailing List Archives. Search String: [How to search] Display: ... _________________ Topband Reflector Archives - http://www.contesting.com/_topband
