The МХО37 series utilizes the internal heating resonator technology (IHR) with arrangement of the oven system together with the crystal plate inside the TO-8 vacuum holder. Such approach results in radical reduction of the OCXO sizes, power consumption and warm-up time. The MXO37/14 and MXO37_14S (SMD) models have DIP14 compatible sizes and pins-out. The oscillators provide extraordinary combination of tiny sizes and extremely low power consumption with superb frequency stability and very low phase-noise level. Fundamental operation at up to 150 MHz enables very low spurious level in the output spectra and thereby substantial reduction of the phase jitter. That makes the MXO37/14 oscillators a very attractive solution for UHF synthesizers and other portable microwave applications.