08-06-2024, 07:39 PM
I managed to get a small amount of time this afternoon to rug up and get out to the shed (before the firewood delivery turned up).
I grabbed a FT140-61 and wound ~12 bifillar turns of 1.25mm diameter enamelled wire.
Across the 6m band it shows a pretty much flat S21 LOGMAG through map of between -20 and -21dB.
This seems adequate to me.
Across the HF band the minimum was about -15dB at 80m then better than -30dB from 7 to 30MHz.
I have more wire and different cores, so once I have split and stacked the tonne and a half of firewood, I may try a FT240-31 core.
(this assumes I can muster any energy after doing the firewood
)
I grabbed a FT140-61 and wound ~12 bifillar turns of 1.25mm diameter enamelled wire.
Across the 6m band it shows a pretty much flat S21 LOGMAG through map of between -20 and -21dB.
This seems adequate to me.
Across the HF band the minimum was about -15dB at 80m then better than -30dB from 7 to 30MHz.
I have more wire and different cores, so once I have split and stacked the tonne and a half of firewood, I may try a FT240-31 core.
(this assumes I can muster any energy after doing the firewood
)