Table of contents
- 1. General
- 2. DBBC2
- 2.1.1. Firmware
- 2.1.2. Tone injection
- 3. DBBC3
- 3.1.1. Firmware installation
- 3.1.2. System verification
- 3.1.3. Tone injection
General
1st LO = 92100 MHz
Total LO (DBBC2) = 85500 MHz
Total LO (DBBC3) = 84100 MHz (UI band)
DBBC2
Firmware
-
Installed new firmware ddc v107 beta3
-
Finished DBBC3 calibration
Tone injection
- noise + tone injected into pins 4 of board A and B
- verified if power levels (attenuation 23)
- set vsi_clk=128
- set dbbcform=astro
tone (MHz) | IF A | IFB | |
---|---|---|---|
528 | OK | OK | |
592 | OK | OK | |
656 | Missing | OK | |
720 | OK | OK | |
784 | Missing | OK | |
848 | OK | OK | |
912 | Missing | OK | |
976 | OK | OK |
Bandpass plot shows that LSB of BBC2, BBC3, BBC4 are corrupted
Cleaned connectors of VSI1 cable connectin DDBC2 to Fila10G. No change. As a test have re-configured Fila10G to use vsi2 instead of vsi1 which has not changed the result. This implies that it is not a transmission problem over the VSI cables.
Update: Due to a power failure on March 3rd the VLBI equipment was brought down (DBBC2, Fila10G). After restarting all equipment the bandpass now looks good and lines are verified in all subbands.