One test should provide the answer.
I 2nd that-time to experiment with antenna positioning.
Another thing; the 20-176 is so darn cheap I went and bought one too. I mounted it to an old torchlamp pole (I keep it around for possible indoor antennas). I was dissapointed in its performance especially on uhf, and 800 was a total wash. It did, however, do really well in the airband. My dukkie antennas smoked it if that tells you anything. If I ever get the inclination and some coax, I will try it outside where it belongs anyway, but the d130j has that job.