Back to Equipment
The SO239 input on the left, BNC output on the right.
End view showing the fan.
Close-up of the resistors.
The power socket at the bottom right is for the fan (12VDC 1A).
Close-up of input circuit.
The heatsink is made from two finned extrusions bolted together to form a 120 x 120mm box section.
The input SWR from 1 to 50MHz. The input SWR rises with increasing frequency to 1.5:1 at 50MHz.
The input impedance from 1 to 50MHz plotted on a Smith chart. The impedance is 50 Ohms at LF, the capacitance between the 500W resistor and the heatsink affects the impedance as the frequency rises.