RF Demo Kit
The TX1000 runs from a USB cable and is controlled from the front panel of the DSA815 (or from a Windows XP application). Shown below is the TX1000 configuration for this test. Switch SW1 and SW5 are closed to connect the two external channels to the front of the mixer.
With the test system configured in this fashion, the DSA815 will show that the output from the Mixer (TX1000) does not totally reject the 100 MHz Carrier. The DSA815's screen image can be saved as a .bmp image – shown here - on a USB stick by inserting the USB stick into the DSA815 and pressing it's print button
The DSA815-TG's span has been configured so that the center of its screen shows any signal at 100 HHz with the entire display showing frequencies between 25 MHz and 175 MHz ( the Span is 150 MHz)
In addition, to illustrating the signals at the expected sum and difference frequencies, this illustration has also displayed the optional Marker Table that lists the X-Y coordinates of the three markers – the unit can display as many as 4 markers- ( As the markers are moved (with the rotary Knob, for example) the Marker Table is updated to show their current position. For this test the marker table shows
- the signals at 90 and 110 MHz are at the same level and
- The carrier is -25db below the sum and difference signals.
When the modulating signal is changed to a square wave, the DSA-815 shows how the harmonic content of it are carried into the output signal of the modulator.
Notice that not only does the screen show the 1,3,5 sequence of harmonics, but cursors 1 and 3 have been moved to show that, indeed, the amplitude of 3rd harmonic is 1/3 (-10 Db) of the fundamental.