The mods for the SD2200 so far are the are the reciever mods, we are working on some Filter mods to sharpen the response from deep targets. We are also testing mods in the Filter stages and looking at increasing the gain and working on a low frequency super deep mode. I will put up more info as it comes to hand, if you want to email me you can at vk3kcg at amsat.org at=@ If I put a real email on this site the spam bots would harvest my email and it would drive my spam filter into overload.