Operation of the G1 receiver has been verified on February 15, in the 210-240 GHz band commonly used at IRAM 30m telescope. In this frequency band receiver output power has been found stable in double sideband and single sideband mixer operations ( 0.1% over 1s timescale). The minimum receiver noise temperature measured in front of the receiver is 75 K in almost double sideband tuning at 220 GHz LO. At the same frequency the SSB noise temperature is about 95 K with about 20 dB rejection of the upper sideband. G1 receiver SSB noise temperature (SSB tuning) and DSB noise temperature (DSB tuning) are presented in Fig. 3. Upper sideband rejection in SSB mode of operation is presented in Fig. 4. The G1 receiver is thus in a correct state and may be used in SSB mode with rejections higher than 10 dB.
Figure 3: G1 receiver SSB noise temperature (SSB tuning) and DSB noise temperature (DSB tuning). Noise temperature is measured in front of the receiver (see note in caption of Fig.1).
Figure 4: Upper sideband rejection of the G1 receiver in SSB mode.