Thanks for your reply AllanH Yes, I'm in the UK. In the cramped confines of the Kennet and Avon Canal with "King" 6024 in this case. I can see that I need to take more account of the recording location. Just as important though, as you say, would be the actual locomotive. I've been virtually on top of a Gresley A4 whistle with no distortion. I'm usually trying to photograph the loco at the same time, so there is often a bit of compromise when thinking about locations. I did start off recording without the micbooster but the recordings seemed to have a lot of hiss on the quieter sections. The micbooster completely solved that and I was much happier with the results. I don't do alot of post processing with the recordings, just edits and fades really. Are there any techniques that would reduce the hissy effects in the recording or editing stage? I'm pleased that you think the equipment I'm using is generally okay. I do need some more wind protection for the MS907 and then perhaps some practice at my local preserved line the "Mid Hants", before the mainline season really gets going again. boojum, I will give that a try on some recordings. As you say, once the recording is clipped/distorted there's not much you can do. Thanks again for your comments, all very interesting, I'll come back when I've had some more practice.