On 2026-02-07 12:19 PM, Tree wrote:
Many people are copying signals way below the noise level with their
DSP radios and FT8.
That depends on the way one defines the noise level. FT8 (and the rest
of Joe Taylor's modes) measure the noise floor in an SSB (2.5 - 2.7 KHz)
bandwidth. However, the actual detection bandwidth for each tone is
in the 5 Hz range. If one adjusts for the detection bandwidth, the
"-24 dB" minimum s/n of FT8 is more like +3dB for tone vs. noise.
How is that possible if that signal just isn't there?
The signal is quite obviously there ... it's a matter of how one defines
the noise.
73,
... Joe, W4TV
On 2026-02-07 12:19 PM, Tree wrote:
So is the takeaway that the older superhet top line rigs are then the
optimum for 160-meter DX?
I guess this begs a question about FT8. Many people are copying signals
way below the noise level with their DSP radios and FT8. How is that
possible if that signal just isn't there?
Tree N6TR
On Sat, Feb 7, 2026 at 8:08 AM Rick Kunath via Topband <
topband@contesting.com> wrote:
So is the takeaway that the older superhet top line rigs are then the
optimum for 160-meter DX?
Or is there something else about the SDR that wins out?
Ir seems like hearing is what it is all about down here.
And an excellent review, thank you.
Rick Kunath, K9AO
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