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For the frequency standard signal transmission of radio telescope observation stations, a phase-stabilized transmission device is designed for both cable and fiber transmission. In this paper, based on previous studies, the device is installed for practical application, including cable transmission from hydrogen room of TianMa Radio Telescope (TMRT) to VGOS telescope and fiber transmission from hydrogen room of TMRT to Sheshan 25m radio telescope. Phase stability and delay are analyzed. The results show that the phase stability of the frequency standard signal is improved by more than 100 times with the phase-stabilized transmission device. The group delay and delay residuals of phase calibration (PCAL) signals are decreased. This is of great significance for Very Long Baseline Interference (VLBI) observations and high-frequency observations.

Phase calibration device has been developed for frequency standard signal transmission based on TMRT (TianMa Radio Telescope)system. With this device, phase stability can be improved 150 times in comparison with no phase calibration. In this paper, principle of phase calibration is introduced. Its performance is tested. And error sources which degrade phase calibration device's performance including thermal drifts, interference signals and VSWR(voltage standing wave ratio)are analyzed.

This paper proposes an active sub-reflector suitable for large radio telescopes, which can compensate both of the deformation of the main reflector and sub-reflector position offsets. The mathematical formula of the main reflector deformation compensated by the sub-reflector is deduced based on Cassegrain and Gregory antenna structures. The position of the sub-reflector is adjustable to compensate for defocusing errors on high and low elevations, which are mainly caused by the deformation of the sub-reflector supporting legs. In this paper, the method of obtaining the optimum position of the sub-reflector from the aperture phase by the interferometric method is introduced. The actual measurement is verified on the Tianma 65m radio telescope, which provides a new way to diagnose the position error of the sub-reflector.

This paper focuses on the measurement of the main reflector gravity deformation and sub-reflector position change on Tianma 65 m (TM65 m) radio telescope. Firstly the paper summarizes the methods of principal measurement. Microwave holography and cross scan pattern are disscussed. Then the gravity deformation of the main reflector over the entire elevation measured by VLBI method is discribed. The measurement accuracy is also estimated. At last, the gravity model is constructed and compared with the simulation. They agree with each other. The formulas along with the simulation give a description between the offsets of feed, sub-reflector and the aperture phase. The sub-reflector position ofTM65 m is obtained by the least square method that applied on the aperutre phase and the formulas. The sub-reflector positions measured are consistent with that of the traditional amplitude method in X , Y and Z directions. This method provides a different way to measure the position model of the sub-reflector.