Hi Don
I believe you mean 200-400kHz not MC. There's nothing long about 400MHz.,

wrote:

Bird Wattmeter Model 43, with seven slugs...Also it has "N" connectors
on it now but also have the factory SO-239 connectors.... 200-400MC
(yes that's right, real long wave), 2-30 MHz (250 watt), 25-60MHz (100
A) , 2 ea 100-250MHz (100watt),(10 watt). and 400-1000MHz (50 watt)