Showing posts with label 60 meter. Show all posts
Showing posts with label 60 meter. Show all posts

06 July, 2020

Recognizing a CQ on the FT8 waterfall

A CQ is not so hard to recognize on an FT8 waterfall display as there is a charactaristic indendation from the right early in the 15 second period. This can be seen in the three circled traces in the figure.


They show a CQ at 711 Hz with SNR 11 dB, one at 899 Hz with SNR 16 dB where my receive cursor is placed, and one at 2003 Hz with SNR 6 dB. These are fairly strong signals so it is easy to see the indendation, but in my experience it works down to almost -10 dB also if the contrast is set correctly with the slider on the display. 

Look closely and you'll see one in the period before also, at 21:15:00 (SNR 12 dB). Try this the next time you run FT8 and I'm sure you'll recognize it too!


24 December, 2014

Getting ready for 60 meter

I have never had any contacts on the 5 MHz or the 60 meter band. But I guess it's time for that now.

Both my K2 and my K3 support it and about 40 countries now have access to this band according to K1ZZ in his column "It seems to us" in this month's QST.

As a first test I ran my 0.2 W Ultimate 3 GPS-controlled WSPR transmitter over night and the image shows the result. I am using an 80 m long loop skywire antenna (horizontal loop) tuned to 60 m.

The results were encouraging with the best DX being UR5VIB in Ukraine at a distance of 1887 km. By the way, considering that it is 1093 km to LA9JO in the north of Norway, one sees the distortion in the map projection used for the Google map.

I have also operated the antenna as a vertical (about 8 meters) with top-hat loading by tying both feed-line conductors together and feeding it against a ground plane. The result is quite similar. The article by Dave Fischer, W0MHS called "The Loop Skywire" in QST November 1985 is the reference for both uses of the loop. The article starts out with this catchy phrase: Looking for an all-band HF antenna that is easy to construct, costs nearly nothing and works great DX? Try this one! This matches my experience exactly as this antenna has been instrumental for my 8 band DXCC.