Peak amplifier for Bird 43 coupler directional wattmeter by F6DFZ

This article describes F6DFZ's implementation of a peak amplifier for use with a Bird directional coupler to measure Peak Envelope Power of SSB telephony waveforms.

Peak Envelope Power

The ITU Radio Regulations define the terms Peak Envelope Power, Mean Power and Carrier Power with regard to a radio transmitter. The terms are defined as:

Note: For use in formulae, the symbol p denotes power expressed in watts and the symbol P denotes power expressed in decibels relative to a reference level.

The advantages of a PEP measurement capability are:

Peak amplifier

Table 1: F6DFZ's meter specific circuit values
Component Value
R1 1,800
R2 6,800
R3, R4 0
R5 1,200
R6, R7, R8 100,000
R9 120,000
VR1 22,000

This amplifier is based on Fig 2 at Peak amplifier for directional wattmeter / SWR meter with F6DFZ's values selected to suit the Bird 43 coupler element, see Table 1 above.

Fig 1: Bird coupler.

Figure 1 shows the Bird remote coupler with 43 coupler element.

Fig 2:Printed circuit board.

Figure 2 shows the printed circuit board designed and manufactured by F6DFZ.

Fig 3: PEP indicating wattmeter meter head.

Figure 3 shows the backlit meter head with PCB housed in a die cast box and custom scaled meter.

A very professional result, start to finish!


© Copyright: Owen Duffy 1995, 2017. All rights reserved. Disclaimer.