For my recent trip to Scotland I purchased a meter from Maplins to get the best aerial direction. When I first used the meter there was no change when plugged into the aerial. I was about to take it back to Maplins when I tested it on the house aerial and then on the aerial I had for many years to put on a mast before having a 530. I have checked the plug for connection or shorts OK. I have taken the 530 off the van but does anybody know how to get into the unit to check connections inside before I start poping out what seem to be the many screw covers