Hmm, in that case, I'm not sure what it could be - Sorry Phil.
My NVUK kit can be a bitch to set up - the DSA isn't as good as yours, it's just a big rubber hose type push on thing. But, once I've got it spot on, I get a bit more range than with my NS Viper.
I asked about the torch because, changing anything with my T20 can make a lot of difference.
- mine has a twist-head beam adjustment. If I get this right, I can see for a good 200yrds. If I get it wrong, I can see bugger all.
Hope you get it sorted mate - NV is a fantastic way to hunt
Also, whatever you do, do not look t