New Allen Telescope Array Development

• Back to NewFeed-athon!, June 20 to 25, 2018

1. System configuration refined and working as diagramed. See the NSG Configuration diagram below.
2. 16 feed pols hooked up to the RF switched. Verified the switch is working.
3. 200MHz filter from all the RFCB outputs removed. Now have 600MHz coming out out the RFCB
4. The HP E4407B and the Aligent EXA N9010Z spectrum analyzers both can be controlled remotely and data gathered.
5. Two SNAPS hooked up and working. Running through system tests now.
6. Figured out where to measure and debug the Feeds and signal chain. See the Signal Measurements Diagram below.
7. A test run of the SNAP all night, all feeds hooked up to the RF switch 1GHz to 10BHz, source: 3c295.
8. Spectrum Analyzer testing. The 9kHz→3G scope could see Casa@1420, but could NOT see w3oh@6667. The other 2 scopes could see w3oh clearly.
9. On the SA we were able to clearly see an 8MHz comb from 1 to 2GHz. We will be investigating. See pic below.

This set of plots shows spectra with taken using the N910A spectrum analyzer of W3(OH). It is an average of 1000 spectra across 0.5 Mhz with 512 spectral points (sweep freq 1 ms). These are the Y-pol measurements, (left-right/top-bottom): 1H 2A 2B 2E 2J 3D 3L 4J.

The half the band without signal was used as a rough “off” calibrator, and plots are (on - off) / off.

We were able to see the 8MHz comb on the new feeds from 1 to 2 GHz. We will be investigating…

Lots of action in the SPR, not much room: