...
AuScope (Hobart, Katherine and Yarragadee)
Report on the Australia-Japan broadband fringe tests (PDF).
Prototype testing on Callisto feed/receiver system at Hobart due for completion in mid August. The system is performing well but some issues with the 12m optics need addressing: subreflector optimization has helped but more work is required.
...
- Fringe test experiments with VGOS mode (using ADS3000+'s DBBC mode for narrow channels VDIF format recording ) has between made between Kashima34,11m, and Ishioka for preparation of Ishioka's participation to VGOS session since beginning of Aug. However fringes with 64Msps-2bit-16ch mode was not gained until 23 Aug. The cause of trouble is not clear, yet. Though fringe was found on 23 Aug. between Ishioka-Kas11 anyway.
- Broadband Fringe test VLBI experiment was successfully performed among Hobart-Ishioka-Kashima34, with broadband recording (1024MHz/band x 4band). Observation frequency range was Fc=(4.36GHz, 5.112GHz, 9.96GHz, 12.86GHz)
- 34m antenna ACU trouble was found on 23 Aug. Now we are trying to fix it.
...
Mamoru Sekido - 24 Aug. 2016
Report on the Australia-Japan broadband fringe tests (PDF).
Yebes
Broadband system temperatures are ~ 50 K - 70 K. The warm amplifiers after the cryogenic ones and before the optical fiber converters had to be removed to avoid saturating the amplifiers used to modulate the optical laser. This increased the Tsys by a factor 2. Furthermore one of the optical channels uses an 18 dB amplifier and the other one 9 dB. This is an issue to be solved in the future.
...