Green Bank, WV


September 12,  2000

TO: R. Fisher, J. Ford, F. Ghigo, R. Lacasse,  C. Niday, T. Weadon
FROM: R. Lacasse
SUBJ.: Minutes of Interference Protection Group 09-12-00 Meeting

In attendance: Fisher,  Ford, Ghigo, Lacasse, Niday, Weadon

Minutes of Previous Meeting

Interference Reports
Review of Action Items:

1 - FAME antenna transmitter

The transmitter power is unclear from the report that has been circulated to some members of the group.  However, the initial design being worked out is for a 20 Watt transmitter.  The transmitter center frequency is 2.1 GHz, which is in a GBT band.  Norrod is looking into the implications of this.  Ford will track this proposal and alert the group if any action is required.
2 -Site-wide Interference Suppression Policy
Fisher and Ford are putting the finishing touches on this document.  It will then be circulated to other members of the IPG for comments.  Then the policy will be forwarded to management .  One of the long term goals of this policy is to enforce reasonable standards throughout the site  by providing both design requirements and manpower to assist in meeting those requirements.  The group bemoaned that fact that, although some people are putting significant effort into mitigating RFI, the general attitude toward site RFI is indifference.
3 -Microwave Oven in Shielded Box
Several things have hampered testing lately including squatters in the anechoic chamber control room and absorber falling off the walls of the chamber.  No progress was made on the shielded box, but the Prime Focus Support Rack was tested. Allowing for the shielding of the receiver room, the rack is about 25 db above acceptable limits.  It is unknown whether additional work will be performed on this rack.

The last time the video cameras were tested, they were barely detectable on the spectrum analyzer.  The spectral processor backend is needed to make a definitive measurement on these.  Fisher will check on the status of connections to this equipment.

4 - Science Education Center Design
The architect is aware of our shielding requirements and seems to be taking steps to insure a compliant structure.  An absorber-covered  labyrinthian entrance to the display is planned, for instance.  Also the projector room will be shielded.
5 -Progress on Monitor Station
White continues to make progress on the design.
6 - Hand-held HF/VHF radio for power switching RFI detection
Niday will make a recommendation in the near future.  The estimated cost is $100 to $300.
7 - Progress on suppressing RFI on tested equipment
As mentioned above, the GBT video cameras were barely detected in the last iteration of testing.
8 - Budget and Manpower for the year
About $4K is left in this year's budget.  Manpower is still scarce. It is hoped that the position paper mentioned in item (2) above will result in the re-allocation of priorities.
Next Meeting: October 17, 2000