The Best MF and LF DX Forecasting tool?

One week ago today my wife and I came home to a house that had been without electricity for several hours due to a major wind storm and was still in the dark.

Did I immediately I walk around the property checking for damage, such as that which might result from fallen branches? No.

Did I rush to the freezer to check for thawed food or melted ice cream? No.

Did I head straight for my best battery-powered radio, an Eton E1 with a choice of wire aerials? Yes.

As mentioned in a previous post, I have only been “seriously” listening to longwave from this location for a few weeks, after spending the majority of this past solar cycle above 530 kHz. At my previous home, in a much more urbanized neighbourhood less than 30 km away, my Perseus SDR found 224 NDBs during my most active period from 2007 to 2009.

Since getting back below 530 earlier this month I have most commonly been making 2-minute long top-of-hour recordings with the same Perseus. Careful examination of any one of the resulting files typically takes at least 20 minutes and yields 13-19 NDBs, including 10 “daytime regulars”. In all of the 24 such recordings for 2018-12-06 UT I found 35 NDBs (best DX: MB).

Last Thursday I logged 75 of them (best DX: HI, QC) during the approximately 2 hours of live DXing that I managed to get in before the power came back to my neighbourhood. By my standards, that was a resounding success; it was by far the most productive longwave session I have ever had. I attribute it to the absence of any discernible RFI, especially considering the limitations of the receiver I was using. The narrowest bandwidth of my Eton is 2.3 kHz. It’s passband tuning works well and helps make the E1 one of the best portables ever but it’s selectivity is still no match to what a Perseus can do. It’s too bad that I was not prepared to run the SDR without AC. Even better would have been to have used Mestor to start it recording at dusk.

What does the above have to do with a DX forecasting tool?

Earlier this year we had a short and very localized scheduled power outage. I used the opportunity to check noise levels on a wide range of frequencies but found nothing dramatic other than the absence of a few persistent buzzes. The outage last week was a completely different event. At one point during the listening session I used my mobile phone to quickly check the electrical utility’s service status and found that the vast majority of customers within 20 km of here were without power. Therein lies the tool.

Over the past 100 years, much research has been done on how, when and where a transmitted radio signal can be detected at large distances from its source. Most of the work to quantify this has been concerned with frequencies above 2 MHz. Others may have come to different conclusions but, from my limited experience, the resulting propagation indicies have been of little or no value for longwave. Background noise from both natural and artificial sources is what matters most. Regarding the former, the concept of a DX season stems from the reduced QRN in winter as opposed to the static crashes from numerous distant lightning strokes in the summer months. Regarding the latter, the time effort and money that dedicated hobbyists, especially MW listeners, put into DXpeditions reflects the value of escaping RFI at any time of year.

Last week’s wind storm gave me almost all of the benefit of a modest DXpedition but at zero cost from the comfort of my own home. Please note that I said almost all. A proper DXpedition is something that you plan for so that you can make the most of it. I was not prepared but I could have been. Power outages are not uncommon in SW BC, mostly because of how high winds can knock down trees which then fall on power lines. Environment Canada and other sources did provide severe wind warnings but I failed to see their silver linings.

From now on, my primary tool for choosing the very best times to search for weak signals below 3 MHz is going to be my local weather forecast. When ferry sailings get cancelled due to weather I will make sure my SDR is poised to run for hours off of SLA batteries.