Topband: Which is most important RX parameter against lighting?

[LY2IJ]

Blocking? Dynamic range? Something other? Nothing helps?

This question rose after WPX weekend on TB with constant lighting all
around including “real video and audio” (and following rainbow). 
Killer combination with abnormal heat for us outside and +35..40 C inside
metal container all nights long.

I heard constant S9 buzz on TX antenna with 350 Hz filter in IC-746. 
Buzz divided into flashes on Beverages – that made possible to RX 
something in between. 

I put two 250m, one 150 m short and one 220 m long reversible Beverages –
all temporary  – 5 directions against just coax one last year. Condition
was really good first night – in that extra heavy QRN I logged W4DR, W4ZV,
WV8JR and CX6VM – thanks for patience, for spending 5 and more minutes 
on me (and I hope I got serials OK). 

390 QSO against 500 last year - 200 k / 300 k.

TU all
Arunas, LY2ij