I measured the 15 Hz zero and the 150 Hz pole for the whitening filter channels of the Generic Pentek board in the IOO rack. The table below gives these zero/pole pairs for each of the 8 channels of the board.
| channel |
zero [Hz] |
pole [Hz] |
Chan |
| 1 |
15.02 |
151.05 |
C1:ASC-POP_QPD_YAW |
| 2 |
15.09 |
150.29 |
C1:ASC-POP_QPD_PIT |
| 3 |
14.98 |
150.69 |
C1:ASC-POP_QPD_SUM |
| 4 |
14.91 |
147.65 |
C1:ALS-TRX |
| 5 |
15.03 |
151.19 |
C1:ALS-TRY |
| 6 |
15.01 |
150.51 |
--- |
| 7 |
14.95 |
150.50 |
C1:IOO-MC_L |
| 8 |
15.03 |
150.93 |
C1:IOO-MC_F |
Here is a plot of one of the measured transfer functions,
and the measured data is attached here: Data.zip
EQ: I've added the current channels going through this board.
More importantly, I found that the jumpers on channel one (QPD X) were set to no whitening, in contrast to all other channels. Thus, the POP QPD YAW signals we've been using for who knows how long have been distorted by dewhitening. This has now been fixed.
Hence, the current state of this board is that the first whitening stage is disabled for all channels and the second stage is engaged, with the above parameters. |