5600 IF frequency sellection

[Naturalarch]

I am using the NI 5600 in combination with a NI 5124 (scope, high speed digitizer).

I want to make an application that can measure a certain signal real accurate, for this it would be nice to be able to chose the IF output frequency. But For now I can only set the input frequency and the program comes with a IF between 5 and 25 MHz. I want to set the IF to a freq as low as possible for instance 5 MHz... with an input of 406MHz.

is this possible?

regards

Joost

[Andy_Hinde]

Hello Joost,
You can do this if you program the PXI-5600 and PXI-5124 separately.

If you use the NI-Tuner driver VIs you can program the 5600 by itself. The niTuner Set Freq VI is what you should use. If you set the span input to a value > 10 MHz, you can tune the 5600 in 1 MHz increments. If the span value is <= 10 MHz, the 5600 will tune in 5 MHz increments.

If you set the desired RF frequency input on the 5600 to 10 MHz above 406 MHz (i.e. 416 MHz) then the resulting IF output will be 10 MHz below  the normal IF center frequency of 15 MHz (i.e. 5 MHz). This applies when tuning in 1 MHz increments.

If the span is set <= 10 MHz you will tune in 5 MHz increments and the RF center frequency will be coerced to the nearest muliple of 5 MHz. So if you set span <= 10 MHz and desired RF frequency to 406 MHz, the RF center frequency will be set to 405 MHz and the IF output would be at 16 MHz. If you set desired RF frequency to 416 MHz, it would be coerced to 415 MHz and the IF output would be at 6 MHz.

Regardes,
Andy Hinde
National Instruments