ESVP :
                General Info 
            
            
               
                The ESVP test receiver is suitable for selective voltage and twoport measurements
            as well as all applications in the field of radiomonitoring and EMC measurements.
            It measures and demodulates AM, FM and SSB signals,  including narrowband and
            wideband interferences. Voltage measuring range is -20 to +137 DBµV.
            
            It was manufactured  somewhere between 1979 until 1987. At that time it's price
            was approximately 60k USD. During these years different models were produced (354.3000.52/53/54/55/56).
            
            
            The main distinctions between these models were their IF bandwidths :
            
             -   7,5 / 12 / 120 / 1000 kHz : Model 52 / 54
             -   7,5 / 12 / 120 / 200 kHz : Model 53 / 55
             -   10 / 100 / 120 / 1000 khz : Model 56
            and frequency range :
             -   20 Mhz until 1300 Mhz : model 52 / 53 / 56,  
             -   20 Mhz until 1000 Mhz : model 54 / 55
            All models are equiped with a GPIB/IEEE-488.2 interface.
            
            Special features of the ESVP are :
            - Synthesizer, frequency resolution 1Khz (SSB 100 Hz)
            - High measurement acuracy (error < 1dB)
            - Wide dynamic range
            
                - NF typical 8dB, preamplifier on
                - 3th order intercept point +20 dBm, preamplifier off
            - Automatic gain correction in the whole frequency range
            - Measurement of voltage, field strength, current, spectral density and 
              attenuation constant with display of physical unit; conversion and
              bandwidth correction factors are automatically taken into account
            - Additional evaluation capabilities of remote frequency and
            
              frequency-offset, including modulation-depth and frequency deviation
             
                    A good second hand ESVP will set you back around 1500 - 2500 Euro when fully operational.
            Any (hardware) error are made visible in the alphanumeric LED display.
                    However, it is essential to have the operating manual, since many operating and measuring
            functions are only initiated with special function codes.
                    
                    Desirable option is the 
            ESVP-B1, Oven-controlled crystal oscillator