I've never understood what is gained by using a balun at the feedpoint in this application. The feedline is unbalanced as is the load. What's the point of a balun. The wild variations in R and X over the range of the band will likely result in heat and loss at the balun. If the point is to keep RF off the exterior of the feedline, that problem vanishes if you have a lot of radials which are needed regardless. The best solution is to put the matching network at the feedpoint but if you opt to match the line to the transmitter at the shack, the vswr loss for 70 feet of 213 won't be terrible and the dielectric will probably withstand the voltage maxima.
73 Rob K5UJ _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
