...with the same antenna as my Rigol 815 spectrum analyzer is a good 20dbuV or more off. Surprise, surprise! All readings were on the low side. One of the main reasons I got the 815 was to see how accurate the sub3G explorer was.
Funny/dumb story? When I first got the Explorer, I used it to measure the output of a Ramsey radio with variable power. I started out low, went up. I kept getting a reading much lower than 250 dbuVs (I thought dbuV=uV). I then turned the power up all the way. Still, way below 250. Finally, I put the Explorer right next to the antenna; Reading was only 60 dbuVs. I thought, wow, I can really ramp up my power.
Twas a learning experience. Trying to figure out what to do with the Explorer now.