next up previous contents
Next: 6.8 IF Cables Up: 6 VLBA STATION SIGNAL Previous: 6.6 Front End Synthesizer   Contents


6.7 IF Converter

The IF converter mixes the receiver output signals with the first LO generated by a front end synthesizer. Two signals between 512 and 1024 MHz are output by each IF converter, one for each sense of circular polarization. The same LO signal is used for mixing with both polarizations in most cases. However, the 4 cm IF converter has a special mode that allows both output signals to be connected to the RCP output of the receiver and to use separate LO signals, thereby allowing the use of spanned bandwidths exceeding 512 MHz. Also, the 90 cm and 50 cm signals are combined and transmitted on the same IFs. The 50 cm signals are not frequency converted, while the 90 cm signals are upconverted to 827 MHz before output.



Jon Romney 2012-01-05