I too have a 705 gold machine. I have used it maybe a dozen times in the back yard and in a couple of parks. The HF coil 5x10"? seems to work well. I had a 305 with the 9" concentric MF previously. I like the 705 better but it may be due to the fact that the discrimination has more notches. I don't feel like I can zero in on the coin ID with certainty like I could with the 305 and the 9". Maybe due to the HF? Am looking to get a 10.5 DD MF coil.