I must say the 870 is an excellent LF performer down to 70Khz. Surely it is, but reading the Kenwood specs for both rigs : Sensitivity (10 dB (S+N)/N) SSB/CW/FSK in the range 100kHz - 500kHz (no BW
First look at band conditions at my 2.50pm is that they still look poor for Tpol. Mind you it is in the middle of my afternoon, but I could see DCF39 on Dot 60. Good luck. Managed to secure a 850S fr