Measuring Transmitter Power
The meter should be connected to the transmitter according to the
“FORWARD SIGNAL” label on the meter (see the illustration on the
opposite page). Depending on the gender of the type “N” connector
on the transmitter it may be necessary to use the double male type
“N” adapter. The meter should be terminated with the 50Ωload in-
cluded in the kit.
Turn the t-meter on by pressing the ON-OFF button. Select the fre-
quency band of interest by pressing the MODE button until the fre-
quency list is shown. Use the SELECT button to scroll through, and
select the appropriate band. A small arrow should be displayed be-
side the band (2.4 for example).
Press the FWD button to read the forward power. A small right-
pointing arrow will appear in the upper right side of the display. This
is the amplitude of the signal (in dBm or mW, depending on the unit
selected in the MODE menu) in the forward direction.
The meter is designed to detect signals between 0 and 20dBm in the
forward direction, and –20 to 17dBm in the reflected. Damage can
occur to the meter if the forward power into the meter (without the
attenuator) exceeds 36dBm.
Most broadband radio transmitters deliver less than 100mW
(20dBm). The 2W 10dB attenuator can be used for sources that are
between 20 and 30dBm in amplitude. Remember to apply the appro-
priate offset in the MODE setting (+10 if the attenuator included in
the kit is used). If the output of the transmitter exceeds 33dBm
(2W), an attenuator of the appropriate power rating and insertion
loss should be used to lower the signal to a level below 20dBm. Us-
ing the MODE button an offset can be configured for attenuators up
to 30dB. If an attenuator is not used, the offset should be set to
“+00”.
While the forward power is displayed constantly on the top line of
the display, the bottom line alternates between the VSWR and the
frequency band and offset settings.
NOTE: A good way to verify proper operation of the 50Ωtermination
(included in the kit) is to make sure that a VSWR of 1.2:1 is displayed
when the meter is connected according to the diagram on the oppo-
site page. If the VSWR is not 1.2:1 the termination should be re-
placed.
T-METER
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