i just got my Advantest R3465 Spectrum Analyzer, after some repair and replacement, i think its good to go, except one thing. the SA showing -13dB at DC. has it got something burnt inside? a DC block maybe? and another thing is, whats funny about this scope is that it can show you down to -200MHz signal, i repeat, negative frequency folks, with some images from positive side (30MHz CAL output in this case). see attached picture. whats going on? the FW broke or something? or it is just the way it is? Waiting your reply thanks.