The 5305B extends the frequency measuring capability of the 5300 Measuring System to the UHF range. The counter features burst or CW measurements to 1300 MHz, separate channels to cover 90 MHz-1300 MHz and 50 Hz to 100 MHz both with 20 mV rms sensitivity, high resolution mode for fast tone measurements, automatic gain control for both channels or manual attenuator control for the high frequency channel, fuse protected high frequency channel, and probe power plus accessory preamp for high sensitivity applications. When operating in the high resolution mode, a phaselocked multiplier gives 1000 times improvement in the resolution of audio tone measurements. This feature is especially useful for servicing equipment using tone modulation for digital encoding on the carrier.