SIGNAL, or N3EG-10, or Bruninga's #1 "ALOHA" coverage problem,
has said ALOHA. Goodbye and good riddance. Maybe I'll mount it on my riding mower and send telemetry
from that, as soon as I can come up with $400 and get it fixed. Maybe I'll just Ebay all my unnecessary TNCs
to come up with the money. The KPC9612 is already gone, being the second 9612 to wind up expendable due
to the uselessness of 9600 baud APRS in the last 5 years. I have two MFJs in the attic due to the uselessness of
30 meter APRS. I have a KPC3 minus with two GPSs in a box marked "APRS CRAP." Now I have a once
useful but much maligned digi with full 5-parameter telemetry in the back of a co-worker's pickup.
see the graph on Findu.com
or the individual graph links:
Outdoor temp Indoor temp AC voltage DC voltage IR intensity
The parameters are:
xxx = telemetry number (usually reset every two weeks to keep it on
the graph screen in WinAPRS)
aaa (red) = DC volts x 10 (voltage of site batteries, measured at TNC)
bbb (blue) = Temperature inside TNC in degrees Fahrenheit
ccc (green) = AC volts (site AC line volts)
ddd (black) = Temperature outside building in degrees Fahrenheit
eee (gray) = Light intensity (relative intensity)
bbbbbbbb = Binary of telemetry inputs: 0 for under 125, 1 for over 126.
aaa=digit 1, bbb=digit 2, ccc=digit 3, ddd=digit 4, eee=digit 6
Interpreting the data: (Remember these readings are for a site at 3400 feet elevation)
aaa: Varies from a normal 13.7 volts downward at times during
the day depending on usage.
Readings of 12.8 or below indicate the charger is down or site power is out.
bbb: Should be close to room temperature inside the site.
There is a thermostatically controlled
fan on the other end of the building, so the temperature will cycle somewhat. The sensor and
the TNC are near the entrance, and a sharp drop in temperature usually means someone
has opened the door.
ccc: Usually our local PUD keeps the voltage a little on the high
side from 123 to 126 volts.
Zero volts indicates a power failure. 118 volts means the site is running on the
backup propane generator.
ddd: Temperature is accurate down to about 34F, but becomes very
non-linear below that.
This sensor is tucked under the ice bridge to the tower to keep it shaded.
eee: Infrared sensor. It seems
to read higher in cloudy conditions than with blue sky
due to the white background. If you see a day with two traces - one parabolic
and one with a "plateau" - there are alternating periods of sun and clouds. Slow
rise time indicates early morning fog lifting slowly.
Description of the sensors:
aaa: This is a voltage divider from the TNC input voltage.
bbb: A thermistor and calibration resistors inside the TNC.
The thermistor came
from a Motorola battery pack.
ccc: A low-current unregulated DC supply. The voltage tracks
the AC line voltage,
and a voltage divider sets the input to the TNC.
ddd: Same as bbb, but outside the building.
eee: Infrared sensor removed from a beam interruption detector.
Questions or comments?
Email me here.
for a graph with a power failure in the last 4 days (look for the red scale
and green scale drop)