Gyula,
My aBitx is an V.2? upgraded to V.3. This reduces the output power but with cleaner output and its more resilient to bad SWR. I have also mounted a temperature controlled fan to the heatsink on the back.
I use long wire antennas 5-6 meters above ground with a 9:1 unun. The one I currently use is approx 20.6 meters long.? ?My output power varies a lot depending on frequency and SWR. I do not have an antenna tuner - the sBitx v.3 can handle bad SWR to some extent.?
Here is a list of my FT8 conditions on the different bands (values from the readout on my sBitx):
Band / SWR / Watts: 80/1.1/20, 40/1.8/36,? 30/2.8/15,? 20/1.4/18,? 17/2.3/16,? 15/1.8/8 and 10/1.5/10.
I have managed to get contacts on all bands - to my own surprise. I think that the power readings are the sum of transmitted and reflected power.
Maybe I should try the delta loop antenna you use.? Can you give links to relevant websites.
I also have had many DX FT8 QSO's with my sBitx? - it's quite fun.
--
Lars
