Tag Archives: FT8

Digital Activity on 23 cm

March 16th, 2022

Last January the QSO BANAT Association added a 23 cm section to their VHF-UHF FT8 Activity contest, open to all digital modes. Tonight it was the 3rd round in this year and my second time in participating. In February I struggled with FT8 and some QSOs could have been much faster completed by using CW, as the one with Roberto, IK2OFO, whom I worked many times before in CW on 23 and 13 cm.

QSOs in the Digital Activity Contest on 23 cm: FT8 in red and FT4 in green

This time I tried FT4 in some skeds and was surprised by the excellent performance of this mode. Of cource I tried with Roberto and it was as fast as in CW. Later at the end of the contest I had QSOs with Andre, DL6AST, in FT4 on 23 cm and on 13 cm as well. After that we tried MSK144 and JT9f (my favourite so far) on the higher band, but without success so far.

It seems FT4 is more robust in handling the varying doppler shift and multipath propagation caused by airplane reflections compared to FT8.

Many thanks to the friends of the QSO BANAT Association for organizing this activity on 23 cm and not dedicating it to FT8 only. This opens space for experimentation, the heart of amateur radio!

IC-9700: Drift on 23 cm

September 25th, 2020

A question in a Facebook group about a GPDSO for an IC-9700 to be used on 23 cm for FT8 inspired me for a quick test. As I use my IC-9700 for 2 m and 70 cm only from home, I connected a dummy load to the 23 cm antenna socket. Next was to tune it to 1,296.174 MHz (of course) and to call in FT8.

The result in brief: No problem to decode with my regular 23 cm rig (OCXO controlled). Just a moderate drift and the signal appeared about 100 Hz too low. Nothing to worry about.

But never the less, I prefer JT9f on 23 cm, as FT8 is useless on aircraft scatter.