Wayne Angevine noticed interference on the 915 UHF profiler
from the Freewave radios. This amounted to raising his noise
floor from about 12db to as much as 24.
A series of tests were performed to try to reduce or eliminate
the problem.
- Reduced signal power to about 5 then 3: no luck,
still had interference, but that was where i lost comms.
- Lowered the antenna. It had probably been 'seeing'
the profiler. This helped, but not enough.
- Rotated the lowered antenna and put power level at 4.
This produced the best results, reducing the noise floor
to 13-15, except for one axis: west, which remained up
at about 18 (possibly from atmospheric reflects, the
antenna was shooting to the west of the profiler, or else
reflection from a nearby Rohn tower).
Results:
- The interference is configuration dependent. Some attempts
improved one of the beams, but degraded others. There's no
doubt interaction with the distance, pointing angle and surrounding
structures.
- No configuration is acceptable to Wayne with the old
Freewave radios.
this is because he already has marginal signal levels, esp.
at the middle height range gates.
- Wayne may be willing to allow us to have comms, except
Between the hours: 9am - 5pm local.
Those are his peak periods of interest.
New Radios Test:
The new models of Freewave radios scan from 921-928.
These are the ones we plan to use for aster.
No Problem with these!
We tried running the new radios in the 'worst' configuration
from before (full power, raised yaggi pointing over the profiler)
and Wayne didn't see any interference.