In contrast, the L-band Type 84's base frequency was 1,200 MHz, so to produce the same spread, it needed to cover about 150 MHz. Normally a magnetron uses a single base frequency, but some "wobble" is evident. But Blue Yeoman also relied on very high power levels; it was only high power in combination with bandwidth that made the system effective. Accordingly, a new 5 MW magnetron was ordered. There was some hope that enemy jammers might not operate against the L-band at all.
