A drain resistor would be advisable if there is no DC return path to earth... if there is no inductor or resistance between the antenna and earth it can develop wind or snow induced static voltage buildup, which can lead to discharges that will cause noise in the receiver. Static voltages can also damage any inline preamps between the vertical and receiver.
Pete _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
