Marshall should leave their recievers unpainted or paint them a light color - the black paint job makes them get ridiculously hot whilst traking a bird in the desert sun in early season. The batteries in mine ruptured because of this while I was tracking my tiercel at 10 am in August. The heat also causes the receiver tuning to drift - you can hear it when you get out of the vehicle and the direct desert sun hits it - the pitch drifts lower. Not a huge deal there, but it does mean you have to move the frequency dial off of the position that you "trust" at a time when you are counting on your telemetry the most. I type this in case anyone from Marshall reads this thread, just a suggestion.