Transfer functions were measured on HAM-ISI unit #2. Results are close between measurements performed with CPSs of the same direction (H,V). (Page1)
However, TFs are not close enough between measurements performed with GS13s of the same direction: (page 2)
- ST1-Act-H3_to_GS13-H3 is lower than ST1-Act-H1_to_GS13-H1 and ST1-Act-H2_to_GS13-H2, by a factor of two.
- GS13-V2 and GS13-V3 record a resonance at 0.975Hz. GS13-V1 records the same resonance at 1.075Hz.
Powerspectra were recorded on GS13s. H3 appears lower that H1 and H2 (page 3). The same measurement was performed with GS13-H2 connected on H3 interface-chassis, and vice versa (page 4). The gain difference follows the GS13s. It confirms that the gain difference observed between the GS13s does not come from the interfaces.
Corey, Hugo,
25 pins octopus-in-vacuum connectors were switched between corners 1 an 3. The ½ gain observed on corner 3 was then observed on corner 1 channel. This gain could then come from whether a bad connection of the 9pin GS13 connector or from the GS13 itself (preamp).
GS13-H3 was pulled out for inspection. Its 9 pin connector was correctly connected. We checked the 9pins connector itself hoping to find a broken female pin. Nothing abnormal was noticed. We tried taking a power-spectrum measurement with another 9pin connector. We could still see a gain of ½ on the instrument’s power-spectrum.
The GS13 was set on the “bench” for a huddle test.