Topband: Fwd: Echo on 160m yesterday morning

[Arthur Delibert]

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 <topband-bounces at contesting.com> on behalf of Andy Cook <g4piq at btinternet.com>
Sent: Monday, February 6, 2017 7:20 AM
To: topband at contesting.com
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
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