Veteran Mel Karmazin To Head Sirius Radio The hard-charging broadcasting executive, formerly of Viacom Inc., is taking the command post at Sirius and reuniting with longtime ally Howard Stern. &lt;FONT face="verdana,MS Sans Serif,arial,helvetica" size="-2" color="#666666"&gt;&lt;B&gt;-The Washington Post&lt;/b&gt;&lt;/font&gt;