12-02-2022, 06:24 PM
Evening-type TEP (eTEP) supports propagation on 2m, but there's a distance limit related to the geometry of the propagation mechanism, which is supported by equatorial plasma bubbles (tubes) that thread the low latitude ionosphere.
From what is known, based on what has been reported of amateur observations and contacts over past decades, as well as technical scientific propagation research, path lengths for eTEP are generally limited by geography (where suitably equipped amateurs live) and the geometry of the propagation mechanism via EPBs. The paths most often reported for 2m contacts range from 4000 to 6000 km; the 'extreme' seems to reach ~8000 km.
It is most unlikely to work JA on 2m from the northern suburbs of Perth, Adelaide or Sydney - Q65 or other digital weak signal modes notwithstanding. I have set out the general condition in my online exposition on eTEP, at: http://home.iprimus.com.au/toddemslie/eTEP-Harrison.htm
Given that paths to 8000 km have been established in the African-European sector, evening TEP contacts on at least 50 MHz, and conceivably 144 MHz, over such distances could be achieved between Australia and Japan, for example, from Coffs Harbour (or Armidale) in Northern NSW, or Woomera in South Australia, to JA7 on the northern coast of Honshu, Japan.
I presented a paper on TEP to the 2007 GippsTech Conference, which set out in detail the necessary conditions for success in making VK-JA contacts. It was published in the Proceedings. If you're interested, you might be able to buy a copy of the Proceedings from EZARC (vk3bez.org).
Take a look at the recent 2m TEP reports of South American / Caribbean contacts on the blog of John EI7GL, at: https://ei7gl.blogspot.com/
Cheers, Roger VK2ZRH
From what is known, based on what has been reported of amateur observations and contacts over past decades, as well as technical scientific propagation research, path lengths for eTEP are generally limited by geography (where suitably equipped amateurs live) and the geometry of the propagation mechanism via EPBs. The paths most often reported for 2m contacts range from 4000 to 6000 km; the 'extreme' seems to reach ~8000 km.
It is most unlikely to work JA on 2m from the northern suburbs of Perth, Adelaide or Sydney - Q65 or other digital weak signal modes notwithstanding. I have set out the general condition in my online exposition on eTEP, at: http://home.iprimus.com.au/toddemslie/eTEP-Harrison.htm
Given that paths to 8000 km have been established in the African-European sector, evening TEP contacts on at least 50 MHz, and conceivably 144 MHz, over such distances could be achieved between Australia and Japan, for example, from Coffs Harbour (or Armidale) in Northern NSW, or Woomera in South Australia, to JA7 on the northern coast of Honshu, Japan.
I presented a paper on TEP to the 2007 GippsTech Conference, which set out in detail the necessary conditions for success in making VK-JA contacts. It was published in the Proceedings. If you're interested, you might be able to buy a copy of the Proceedings from EZARC (vk3bez.org).
Take a look at the recent 2m TEP reports of South American / Caribbean contacts on the blog of John EI7GL, at: https://ei7gl.blogspot.com/
Cheers, Roger VK2ZRH