I recently started a post on Reddit about HF band conditions (here’s the link), and someone left a great comment asking why 160 m is missing from most band-condition charts — even though it’s included in nearly every modern transceiver.
It’s a good question, and I think it’s worth explaining.
160 m isn’t “forgotten” — it’s just very difficult to represent accurately with the usual space-weather inputs like Solar Flux (SFI), and the planetary A and K indices.
Most HF propagation models — including the one I use at DXLook.com — are tuned around the F- and E-layers, which govern propagation from 80 m up through 10 m.
But 160 m behaves differently — it’s dominated by the D-layer, which absorbs signals during the day, making skywave propagation nearly impossible.
At night, Topband can be great, but that depends much more on:
So 160 m isn’t ignored — it just doesn’t follow the same physics that most HF condition summaries are based on. Until we have a good way to include noise and seasonal models, it’ll stay a band that rewards patience, timing, and experience.
It’s a good question, and I think it’s worth explaining.
160 m isn’t “forgotten” — it’s just very difficult to represent accurately with the usual space-weather inputs like Solar Flux (SFI), and the planetary A and K indices.
Most HF propagation models — including the one I use at DXLook.com — are tuned around the F- and E-layers, which govern propagation from 80 m up through 10 m.
But 160 m behaves differently — it’s dominated by the D-layer, which absorbs signals during the day, making skywave propagation nearly impossible.
At night, Topband can be great, but that depends much more on:
- Geomagnetic quiet (low K/A)
- Local QRN (lightning and noise)
- Season (winter is best)
- Latitude
So 160 m isn’t ignored — it just doesn’t follow the same physics that most HF condition summaries are based on. Until we have a good way to include noise and seasonal models, it’ll stay a band that rewards patience, timing, and experience.
