The engineer for claro phone
company contacted AO on 06may14 reporting a problem that they were
having with 5 cell phone tower sites in Utuado. The problem
started around 21apr14. He wondered if we had seen anything
different in that frequency range starting on 21apr14. The
problem was with the uplink bands:
835-845 Mhz
846.5 - 849 Mhz
This is the same engineer who helped us when we
were searching for the 430 Mhz problem a few weeks back (it
ended up having nothing to do with Claro).
I looked at the rfi hilltop monitoring system to
see if anything unusual appeared around 21 apr 14.
System description of the hilltop monitor system:
a disc cone antenna going 10 Mhz to 1.5 ghz, and a high
frequency antenna 1 to 10 Ghz.
connected to a filter bank with amplifiers
and then to a hp spectrum analyzer.
The system cycles through 20 bands covering 10Mhz to 10 Ghz
At each band , the filters, amps are set up , and then a 1
minute peak hold is done on the band
This data is then read back into the computer.
It takes 20 minutes to cycle through the 20 bands, so each
band is sampled once every 20 minutes
The 810 to 1100 Mhz band covered the Claro uplink bands. It is
sampled with a 100Khz resolution bandwidth.
The two dynamic spectra show power vs time for 15apr14 ->07may14
The horizontal axis is frequency 810 to 1100 Mhz
the vertical axis is day of month for april14
numbers > 30 are just the beginning of may..eg 35 =
05may14
White is stronger, dark is weaker power. (it is an image of
data on a db scale).