Hannah, Stefan, Daniel
It was determined that the broadband noise we've been seeing has been caused by the Harmonic Generator (SN 1043-03, DCC S1000798). To see if this was an issue with the unit or if this is the normal operation, we tested the spare. Using an RF frequency of 9 kHz, lowpass filter of 10.7 kHz, we tested all seven outputs and measured the following noise:
|
|
Voltage V |
Noise nV/√Hz |
Noise 1/√Hz |
|
9 kHz RF signal |
0.380 |
8 |
4.2x10-8 |
|
2x Output |
0.205 |
23 |
1.2x10-7 |
|
3x Output |
0.177 |
105 |
5.9x10-7 |
|
4x Output |
0.404 |
34 |
8.4x10-8 |
|
5x Output |
0.243 |
55 |
2.2x10-7 |
|
6x Output |
0.268 |
172 |
6.4x10-7 |
|
10x Output |
0.337 |
252 |
7.5x10-7 |
|
15x Output |
0.291 |
197 |
6.8x10-7 |
The x5 output is what we're interested in, and the noise seems to be about the same as what we're already seeing. The power supply was also checked to make sure there were no stray signals.