The Micran SK4M-50 Spectrum Analyzer operates from 100 Hz to 50 GHz with a resolution bandwidth from 1 Hz to 10 MHz. The analyzer has a Third-order intercept (TOI) level up to +20 dBm, a DANL < -165 dBm/Hz and a low phase noise of -125 dBc/Hz at 1 GHz signal from 100 kHz offset. It has an in-built input attenuator, a thermostatic YIG-preselector and a low-noise amplifier. This instrument can be used when producing and maintaining various radio and microwave hardware. It can measure various parameters of transmitters, radio-receiver paths and other active microwave devices.