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Steve Bowden

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About Steve Bowden

  • Rank
    Minor flare

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  • Gender
    Male
  • Location
    Muston, North Yorkshire
  • Interests
    Photography, Astrophotography, Astronomy, Amateur Radio
  1. Marcel - I am basically mirroring this (with a few edits) from your Facebook page as an addendum to your request for knowledge. I do amateur radio and in the past, I used to partake very seriously indeed in High Frequency (hf) contesting picking up a couple of world records and several World #1 spots. These contests were 48 hours in duration (CQ World Wide morse and voice) and the aim was to work not only as many stations as possible but also as many different countries on each of 5 hf bands (1.8MHz to 28MHz). The 28Mhz band I needed this information the most. To achieve these results I needed bang up to minute propagation results and these results were in a separate window on another screen so I could monitor and adapt to change. I required a livestream for: SFI, SF density, sunspot counts, geomagnetic storm forecasts, SIDs etc. So I had a good idea of how stable/unstable the ionosphere was at a given time. Despite a few of these contests coinciding with the peak of the sunspot cycle and the ionosphere fairly stable, the data was still vitally important to work out when the high bands were open and and when to change frequencies. Especially 28Mhz and 21MHz which are heavily influenced by solar flux levels and I needed to maximise continental band openings. My main source of real time information came from Solarham although I also have a good grounding in propagation and have done propagation modelling in the past. From a radio communications aspect and working out band openings on hf, there is also the "grey line" to consider. The grey line are the times where day goes to night and vice versa. Affecting different ionospheric layers (mostly the D layer) but you can get band openings to specific parts of the world stronger than any other time. For example, when I wanted to work west coast USA on hf, the "window" of opportunity was only about 20 minutes and signals became pretty strong during this time and then died down to zero audibility. Knowing this information meant I could not only point a directional antenna towards the area I wanted to chat to but also work out the maximum usable frequency (MUF) I needed to use for that moment in time. Then of course following this grey line as it progresses across the earth as the day goes into darkness and alternatively comes out of darkness presenting a path for two distinct areas on the earth. When conditions are right, it is akin to pointing a narrow torchbeam onto a globe and slowly rotating it. I remember consecutive contacts (ie the loudest) going from New Zealand, Australia, Indonesia, China, Malaysia, India .... and I knew Saudi would be peaking next and it was. Hf propagation can be very interesting Yes, I did keep an eye on these details continuously and they were windowed on a second monitor so I could see if an ionospheric storm was building up and for any signs of Dellinger fading or Sudden Ionspheric Disturbance (SID) - I monitored SIDs using a VLF antenna through a computer sound card. SIDs are also useful for detecting aurora activity as it arrives due to the dampening effect on the ionosphere. This in turn can have an enhanced effect on VLF and VHF signals due to the saturation of the D and E layers you can actually hear stations from a lot further than expected. On VHF it is normally "line of site" communications but you can hear stations more than 150 miles away (another aurora indicator). Using either morse code/voice this gives rise to something known as auroral scintillation where you can actually hear a "dualling" on the signal. This sounds very different from the 1/7th second echo due to the hf signal being received via both short path and long path at the same time. Sorry, typing for England but hopefully there may be some nuggets that tie in with your train of thought Hope this helps Marcel. Steve
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