external local oscillator

[margarette]

Hello. I have NI PXIe 5673. In what instances do I need to use an external local oscillator instead of the NI PXIe 5652. I will be transmitting a DSB-ASK signal with a carrier frequency of 915 MHz. Sorry, I'm new here in NI so I'm quite confused. Thank you!

[Benjamin38]

Hi Margrette - 

To answer your question, the ability to connect to an external LO is simply to give the end user freedom to use a different device than the one used in a Vector Signal Generator bundle/combination if they wanted to.  Connecting an external LO could be useful if you have an LO with lower phase noise, lower harmonics, or faster tuning time than the NI 5652.  If you do not have another LO in your system, there are no worries in setting up generator to any external hardware.  You will be able to generate that IQ modulation at that specified frequency with the PXIe-5673.