Bird Technologies 4527 - Manual (Page 39)

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Chapter 6 Model Differences
Bird 43P Peak Wattmeter
The Bird 43P Thruline Wattmeter is the same as the Bird 43, with the added
capability of measuring peak power in AM, SSB, and some pulse applications. A
conversion kit (P/N 4300-400) is available to give peak reading capability to any
standard Bird 43. This kit comes with all necessary parts and easy to follow
instructions for simple and quick conversion.
Special elements are not required. However, the element power rating must
match the peak power to be measured.
Example - If 1000 watt peaks are expected, use a 1000
watt element.
Operation
There is a push button on/off switch on the right side of the meter.
•
To read peak power, push the switch in. The red LED will light.
•
To read CW power, push the switch again. The LED will turn off.
Peak Detector Response
Since the peak detector’s response time is about one second, a short delay may
be noticed before the meter reading stabilizes. This will also be noticed when
the transmitter is turned off. In voice modulated systems, the meter reading may
fluctuate by 2–3 minor scale divisions as the peak detector attempts to follow
the power variations.
Rectangular Pulses
When measuring rectangular pulse power, note the following signal require-
ments:
•
Duty Cycle: 2%, minimum
•
Rep. Rate: 100 pps, minimum
•
Pulse Width: 200 µs, minimum