IF upgrade status – Aug 3, 2012
Bandwidth doubling assembly: A seventh bandwidth doubling assembly has been modified for wideband transmission. It will be tested and returned to the summit within a few weeks.
IF adapter plates: All of the adapter plates have been bench tested. Plots of the gain flatness for all the assemblies will be posted on the twiki shortly. Gain flatness through assorted fiber optic links has been measured. I will post these plots as well. Phase stability measurements were made for a single unit, the data show about a 0.2 degree shift in phase per 1 degree C change in temperature. The plan is to ship the modified Cambridge IF enclosures to Hilo for an end to end test of the wideband IF system.
Continuum detector: The design of a pcb for the 14 channel continuum detector is in process. Software development for the rabbit microcontroller and power pc is in process.
From Derek
C1DC: Solomon has finished the mechanical design for the upgrade. We came up with the idea of using the existing mounting holes for the Ortel receiver. We are still waiting for the threaded stand-offs to complete the assembly in C1DC S/N 1 (spare in Hilo). Still to go are the RF tests which include S21, P1dBc, and NF.
BDC: Ryan C. has essentially completed one bracket which has the capability of processing 2 IFs from one antenna (or 1 IF from 2 antennas). He still has some mechanical and DC wiring work to do on the bracket itself but this should take only a few days. We plan to install the bracket into the chassis for the test in August. The 8 - 10 GHz sweep looks OK, though I wish it were better, but the 10 - 12 GHz looks pretty bad. But keep in mind that the spectrum is reversed for the 10 - 12 GHz plot and any falling gain slope for the input signal will have the opposite effect of flattening this spectrum.