Bird Technologies 6156 - Manuale (Pagina 22)

CAUTION
The diode assembly is an ESD sensitive assembly, use proper ESD
precautions.
Measuring
Transmitter
Power
1. Place the wattmeter in a position
where the meter can be seen while the
transmitter is being adjusted.
+
Note: The meter indicates power dissipated in
the load portion of the instrument.
2. Connect the wattmeter to the trans-
mitter with a short piece of 50 ohm ca-
ble, preferably under five feet in
length.
+
Losses introduced by the cable between the
transmitter and the wattmeter, if significant,
must be added to the power indicated on the
wattmeter scale.
3. Plug the crystal diode into either the
Black (Low, x1) or Red (High, x10)
range socket. Make sure the diode
snaps into place. Flip the switch, on
the meter, to either the Black Scale or
the Red scale, depending on the power
to be measured.
+
Note: If you are unsure of the power to be
measured, plug the diode into the high range
socket (red side).
4. Apply transmitter power.
5. Rotate the diode in the socket to ob-
tain the maximum deflection on the
meter. The deflection should not ex-
ceed one division.
6. Make power measurements.
When switching from the wattmeter back to the antenna, it
may be necessary to retune the transmitter slightly. This is
due to the difference in VSWR between the wattmeter and
the transmitter’s antenna.
10
Bird Model 6104/54/56 Termaline Wattmeter