I will second the voltage drop when the generator kicks in.
One possible solution.. A small 300 or 600 watt TRUE SINE WAVE inverter, Wire it so it provides power to the Dishnetwork receiver (Check the ID plate on the receiver that will tell you how much power. Whatever it says, Double it when you buy the inverter,, IE if it says 180 watts, go for 360 or more)
Run that off the 12 volt and his problems should go away.
NOTE this needs to be a "Stand alone" inverter, not an inline
And he needs at least tx the inverter's needs in converter as well
(If the Receiver draws 200 watts. That's 20 amps, so he needs at least 40 amps of converter)