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Property of Jim Olliff DBA JO-COMM 10/12/2007
These measurements taken in an outdoor environment, with no
control of temperature or humidity. Measurement results only
provided for comparison purposes, tolerances are not specified or
guaranteed. These measurements are limited to measuring one or
more examples and may not be representative of all similar
products. By no means, is this meant to discredit or enhance any
products made or supplied by any manufacturer or supplier. Any
one else making these measurements may have different results.
Test Equipment:
+ 1500 watt switching power supply at 13.8 VDC Powertec MultiMod™ Series
Model 60-BBYEFT-11-P1-S1814
+ Extech 380900 Dual Channel Digital Volt Meter ±(0.03% + 3 digits)
+ TPI 153 Digital Volt Meter (used for measuring current) ± (03 %)
+ Load 18 each 12VDC 50 watt light bulbs with switching for six individual lamps
and 2 switched banks of 6 bulbs
+ 50 amp Shunt with 1 mV represents 1 amp of current 0.5% accuracy
+ Extech 4510 IR Thermometer (± 2% of reading, or ± 4°F/ ± 2°C,
whichever is
greater) 1:8 distance to target ratio, fixed 95% emissivity covers 90 % of
surface applications,
These procedures where planned to minimize measurement error, make the
measurements only through the specified cable length or device by using sense
wires, and only add the contact of the mating connector for connectorized devices
under test. Connectors on various splitters measured at maximum separation.
Test equipment tolerance and the light bulbs are variables not taken into account.
Manual measurements taken close to the time intervals but may be off, based on
instrument transition and human error.
These measurements are typical of what may be expected and give a ballpark for
calculating required power, cable size, and device voltage loss to provide greater
that the minimum voltage required, for a radio. Transmit and receive currents,
along with duty cycle (percentage of transmit vs. receive time) would be used
as
part of the planning process.
Measurements of additional devices, over longer time are planned, and will
be
added in the future. This data is subject to updating as improvements in
the
process are made.
This is an example of the test setup used in measuring power splitters.
The IR Thermometer, Extech 42510, placed close to the power splitter and moved
to find the maximum temperature, and allowed to settle for approximately five
seconds before logging the temperature.
The Extech 380900 Dual Channel Digital Voltmeter: channel one, used to
measure the voltage drop on the positive lead across the device under test.
Channel two, used to measure the voltage across the device at the output side
closest to the load.
The TPI 153 used to measure the current through the shunt. One amp equaled
one milivolt on the digital voltmeter.
Cable Measurement Procedures:
+ Cables assembled with sense leads at each contact
+ Each cable was stretched out
+ The load current stepped by switching on an additional bulb
+ Temperature of the cable was measured and recorded approximately every
30
seconds, the IR thermometer clamped approximately one inch above the cable
+ A computer tied to a dual channel voltmeter recorded the voltage drop across
the positive lead and the voltage across both leads on the side nearest the
load
+ The voltage measurement was across a 50-amp shunt produces one mV for
one amp of current and is displayed on a digital voltmeter
+ The measurements stopped to keep from exceeding 150 °F
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