I've been testing the new Marshall Radio RT Turbo transmitter. I have been using one for about 3 months now. I'm thrilled with its durability and performance. I'm using the 216 and 218 MHz transmitters with a 13 inch antenna but are available in 433 and 434 MHz with a 7 1/2 inch antenna. In the 216 MHz through 219 MHz Marshall uses the longer antenna on both the RT Turbo and the RT Standard. The reason for that is to get the maximum output from the transmitter. I know with a 13 inch antenna it sounds long but using a TrackPack it hardly goes past the end of the tail feathers. The New Marshall Radio RT Turbo has about 4 times the power of a Power Max Transmitter... The Relative Power of Marshall Radio Transmitters ( Scout + 4 db ),( RT Plus +5 db ), ( PowerMax +8 db ), ( RT Standard +11 db ) and the( RT Turbo + 17 db ). I have just completed a duration test at room temperature. With a fresh battery I got 24 hrs at high power before it goes into the Apollo mode, then 9 more days of continuous running in the Apollo mode. The freezer test at -10 F, I got 7 days of continuous running but it would never be that cold under the birds feathers. They are pushing the output to the maximum and still getting that kind of duration... Because it is a Marshall transmitter most settings can be programed to fit a special need. Some of the settings that can be changed include, low battery alarm, pulse speed and length as well as frequency within the original frequency band. The new Marshall Radio RT Turbo is the most powerful falconry transmitter on the market that I know of. For all of you who are flying big ranging longwings, this is the one for you.