Jari, OH6BG, has been constantly improving VOACAP Online, and it is now my favorite Propagation Prediction Tool. I have noticed that over the past year or so many new features have been added – such as specific station information – which makes it more accurate. I also really love the new ability to get the checkerboard prediction charts by month or year. But he has now added something that really helps me quite a bit, and that is detailed grey line time information as well as a map, as you see above. You know from my propagation studies, I am constantly switching between propagation software (and I use VOACAP Online mostly these days because I love the “data visualization” it offers) and DX Atlas. But that was pretty good, but Jari has upped the ante with this:
This is a very accurate chart of grey line, and includes not only the three types of grey line twilight (civil, nautical and astronomical), but also shows dawn and dusk at each end point in the radio circuit.
This is absolutely critical for Top Band, and is also very important for all low bands. But on Top Band – perhaps the band least understood propagation wise – since VOACAP does not predict it (and is a bit weak on several of the low bands), this new feature fills in the gap very nicely.
When I worked FT5ZM and VK0EK on Top Band, the timing was absolutely critical. You really had to know when to strike – otherwise you might miss a 10 minute or even 5 minute or less opening!
It isn’t quite this tricky on the higher bands, but I very clearly remember VU7RG and ZS8M both being greyline ATNO’s and both on 40M – at dusk – and VU7RG happened during the “set” time, and ZS8M happened on the “dusk” time. Now – here is the real “kicker” – when you look at the difference between pre and set and then set and dusk for mid October 2017, you will see that it lasts 20 minutes. That is EXACTLY how long my VU7RG and ZS8M openings were. These were not the only times I have experienced this, and it happens on all of the low bands.
One of the funny things I always see is a DX Cluster spot where someone is “asking” the DX-pedition to come on a band – like 160, 80 or 40M when its mid day at the DX-pedition location. This new feature would be great as an education tool.
In fact, I like it so much, I will say that once you get really expperienced at DX-ing, this might be THE most important skill. I do not have the best QTH or antennas. They are respectable but I am no big gun. HOWEVER, I beat everyone to several ultra rare DX-peditions because I could really guess what band they would start on based on grey line.
This my favorite data visualization for a year long prediction. It is crisp and very easy to understand. I’m looking at only the last three months of the year since that is the quarter closest to when 3Y0Z will be on the air. I can also look ahead to January, 2018:
No matter how you slice it, conditions for Bouvet look better than I had expected given conditions as they have been the last few months or so. I have a theory that the month leading up to summer solstice and then after is usually crummy – at least on the low bands. This makes a lot of sense – because the grey line and even the night time duration is so much shorter than during the winter.
HOWEVER – you also need to look at what is going on in the DX QTH’s part of the world – be they in the northern, southern or equatorial regions.
The new VOACAP Online gives you EVERYTHING you need now – from 160M all the way up through 10M.
Fantastic job Jari – you just made all of us low banders very happy!