Thanks for the help, after much head scratching and swearing I finally managed to upload the vixen call I wanted.
It was worth the hassle, had a great night foxing. Started at 17.30, five minutes later shot a vixen that can trotting in to the snowshoe call. Went a bit further and tried the vixen call at a likely spot. 5 mins later there was a dog fox four marshes over (a good 800m away) slowly but steadily making its way in to the call. After a few minutes it ended up in the gateway about 30m directly behind the landy. I had to hang out of the truck window and shoot left handed, I was sure I’d miss but the shot was good and he dropped on the spot. Then about half an hour later I spotted another fox so I thought I’d try the vixen call again. It worked again, unfortunately the fox got to about 200m and decided something was wrong so started to move away. He stopped on the end of the dyke so I took my chance, another perfect clean shot. I measured the distance this morning, 278m my new personal best. The pulsar apex thermal scope is a serious piece of kit.