Topband: FT8 on 160m

[Tim Shoppa]

As a practical matter there are several 2 kHZ segments of each band that are now devoted to 24x7 JT65, FT8, and other digital modes. Weak signal CW work - eg working rare mults or even just weak guys from common mults - in those segments just isn’t gonna happen.

Substantial parts of 80M and 40M have been pretty bad for several years now with SAILNET and other automatic modes.

Tim N3QE

> On Nov 27, 2017, at 3:43 PM, Roger Parsons via Topband <topband at contesting.com> wrote:
> 
> As we all know, CQWW produces huge activity on all HF bands. This year I was hearing stations up to well above 1850kHz. I have found that trying to run Europe is often more productive in the 1840-1850 segment, presumably because it is less crowded than lower in frequency. 
> 
> 
> Late in the contest I started to CQ on about 1842kHz, and after a while, and several QSOs, was told (on CW): "Please QSY. 1840 is reserved for FT8. Good luck in the contest." Ignoring the fact that nobody has a reserved frequency on any band, I thought OK, don't want to upset anybody, and moved to 1842.9kHz. Shortly, the same message arrived.
> 
> My (probably incorrect) understanding is that FT8 stations are using USB with a carrier frequency of 1840kHz. So a CW station on 1842.9 should be out of their passband. I did listen carefully and could not hear any FT8 transmissions above 1842.2. (I have multiple receive antennas in a very quiet location.)
> 
> I believe that FT8 transmissions in principle use a microscopic bandwidth, but it appears they actually need a wide clear channel.
> 
> Yes? No?
> 
> 73 Roger
> VE3ZI
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