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RFI's
-----

Broad RFIs are given by the frequency range that they cover, plus a
brief description, while sharp spikes are just given as a single
frequency. A VERY approximate peak height for the RFI in Tsys is given
for each of the three days. No entry for a date means that the RFI was
not seen that day.


-------------------------------------------------------------------
16/11 18/11 19/11 Notes
-------------------------------------------------------------------
1783.5 - 1786.5 , , 0.1T Mode-like
1791.5 - 1793.5 , , 0.1T Mode-like
1805.0 - 1813.0 0.1T, 0.2T, 0.4T Set of spikes (Poln A?)
1832.0 3T, 10T, 1T Spike (Poln B?)
1889.2 7T, 1T, 1T Spike (Stronger in Poln A?)
1889.0 - 1911.0 , 1T, 6T Mode-like with 4 quasi-modes!
1900 1T, 0.5T, 0.1T Spike
1910.5 - 1914.5 , , ~15T Set of spikes
1920.5 - 1925.0 , , ~25T Set of spikes
1932.0 - 1934.5 320T, 800T, 200T Set of spikes - PCS SYSTEMS ?
1935.8 - 1940.0 6000T, 40000T, 15000T Set of spikes - PCS SYSTEMS ?
1945.5 - 1947.0 500T, 300T, 4500T "Galaxy-like" - PCS SYSTEMS ?
1950.5 - 1952.0 500T, 300T, 500T "Galaxy-like" - PCS SYSTEMS ?
1975.5 - 1977.2 , , 20T Set of spikes - PCS SYSTEMS ?
1978.5 150T, , ~35T Spike - PCS SYSTEMS ?
1979.7 150T, 40T, ~20T Spike - PCS SYSTEMS ?
1988.0 - 1989.5 135T, 2300T, 1700T Broad and spiky - PCS SYSTEMS
2030.0 - 2032.5 , 0.1T, 1T Mode-like
2037.0 - 2039.5 , 0.3T, 0.5T Mode-like
2066.0 - 2069.0 8T, 4T, 4T Broad and spiky
2083.0 - 2086.0 , 0.2T, 0.7T Broad and spiky
2100.5 - 2102.5 1T, 3T, 1T Broad and spiky
2197.7 4T, 0.1T, 1T Spike
2242.5 0.1T, 0.7T, 0.5T Spike
2320.0 - 2334.0 1T, 0.3T, 1T "Galaxy-like"
2343.0 - 2345.0 0.2T, 0.2T, 0.2T "Galaxy-like"
2400.0 - 2462 0.5T, 0.5T, 0.5T Wide set of spikes
2445.0 - 2460.0 , 5T, Very broad and continuous -DIGITAL AUDIO?
2450.8 10T, , 1.2T Spike (Stronger in Poln A?)-DIGITAL AUDIO?
2460.8 3T, , 0.4T Spike (poln B?) -DIGITAL AUDIO?
2467.5 - 2472.0 27T, 60T, 45T Broad and spiky -DIGITAL AUDIO?
2485.5 , ~300T, ~100T Spike -DIGITAL AUDIO?
2501.2 3300T, 7000T, 9000T Spike -DIGITAL AUDIO?
2505.8 ~100T, ~250T, ~500T Spike -DIGITAL AUDIO?
2513.2 7700T, 2000T, 8500T Spike -DIGITAL AUDIO?
2517.8 , 1900T, ~250T Spike -DIGITAL AUDIO?
2523.8 ~100T, , ~100T Spike
2549.2 40T, 80T, 40T Spike
2561.2 147T, 150T, 250T Spike
2800.0 0.1T, 0.1T, 0.1T Spike
3043.2 , 0.05T, Spike
3089.2 , 0.05T, Spike


Combs
-----

In addition, a number of "combs" are seen on the records:

i) 2501.2 + 23*n MHz; it is doubtless significant that the frequency
separation of adjacent boards is 23 MHz. Probably the aliasing effect
of saturation by one of the strong RFIs?

ii) 1765.2 + 23*n MHz; as above.

iii) 2501.2 + 6*n MHz; doubtless related to saturation by the strong
RFI at 2501.2 and 2517.8 MHz?

iv) 2517.8 + 12*n MHz; just 4 spikes at 2505.8, 2517.8, 2553.8 and
2565.8 MHz. Related to the strong RFI 2517.8 MHz.


Resonance Modes
---------------


Suspected resonance features were idetified by noting spectral
responses that were quasi-Gaussian of a few MHz total width, present on
each of the 3 days on which data were taken.

1829.5 - 1832
1956 - 1959
2012 - 2014.5
2080 - 2082
2128 - 2134
2196.5 - 2198.5
2257.5 - 2261
2579 - 2582.5
2662 - 2663.5
2745.5 - 2747
2751.5 - 2754
2816 - 2819
2868 - 2872
2929.5 - 2933
2987 - 2990.5
2993 - 2998 (mode? Bigger in one poln than other)
3052.5 - 3058 (mode peaks at freqs differing by 1 MHz in 2 polns)
3110 - 3116 (ditto)


S. Stanimiravich and C. Salter
November 2001