I've had the SDS-100 and the SDS-200 for over one year now. I've beat my had against the wall every since I purchased them. Sentinel has never worked so I bought programming on SD's Micro's. I've never been able to receive my county's trunked systems, only VHF and UHF channels. State trunked systems seemed to work OK. Now that our county has changed from 800MHz to 700MHz, I was back to trying to program with sentinel again. Today is day 6 and I can't get anything to work. I tried to load the old SD's up to Sentinel and modify them. Nothing worked. I purchased 3 new SD Cards and copy the old favorites to them and reinstalled them. Nothing but errors. I reformatted the cards about 6 times now with aftermarket formatting programs being as Sentinel formatting didn't work. I've my errors were to "clear user data" and that makes no difference either. I've tried to copy the original card directly and drag & drop to the new cards and nothing but errors. Over the last year, I've deleted and reloaded Sentinel about 16 times now. Nothing works, I finally just went to Zip Scanners and purchased about $160 of programming with SD Cards. Obviously it's just me, but I see that others have issues and most have solved their issues with the help of others here. Very nice to see those who dive in to help. The cost of these scanners and adding programming twice now for 2-3 counties twice now, I beginning that I need to get rid of them next time they need updating. None-the-less, I'm just wondering if anyone else has had so much trouble with sentinel and I would like to know if I can update or add trunked stations to the new Favorites once I receive the new SD Cards from Zip Scanners. A lot of wording that is mostly venting. Suggestions very much welcome for future programming. Thank you very much!