Elecraft W2 Watt-meter Manual - Manual (Page 7)

7
Directional Coupler (Sensor)
A directional coupler is used to measure RF power and standing wave ratio (SWR). A typical directional coupler
is shown below. At least one sensor must be connected to the W2.
Computer Interface
The computer interface provides access to advanced functions controlled through your personal computer (PC).
A suitable interface cable is included to connect your W2 to your computer through a USB or RS232 port,
depending upon the cable you chose when ordering your W2. The W2 Utility program for your computer may
be downloaded free from
www.elecraft.com .
Firmware Updates
From time to time, updated and improved firmware may become available for the W2. The latest firmware may
be downloaded from Elecraft and installed using the optional PC interface and the W2 Utility program. Updated
program files may be obtained in two ways. You can check the box in the W2 Utility that says “Copy new files
from Elecraft into local folder”. This will download the latest production released firmware. Optionally, you can
download the new file from the Elecraft web site manually and place it in a local folder, then browse for it
within the W2 utility. This is the way to access the latest Beta firmware available from Elecraft.
A new firmware load is initiated by turning the W2 off, then holding the SENSOR button depressed while
pressing POWER to turn the W2 on. The green 1 LED on the power bar graph will blink indicating the W2 is
ready for new firmware.
When you start loading new firmware, the green 1 LED on the power bar graph will turn off and the yellow 2W
LED will start flashing as new data is received. If the 2W LED stays on but doesn’t flash, data is not being
received by the W2.