Interface between system rf preamplifier assemblies and electronic converter; 0.25 ghz to 18.0 ghz radio frequency range; seven bands; 20 millisec transfer switching time; two inputs; oper pwr rqmts 115 vac, 60 hz, single phase, 110 watts; o/a dims 19.0 in. Lg; 18.0 in. W; 5.25 in. H; rack mounted