Note
Inductors and capacitors are the fundamental building blocks for RF design, and the MFJ-5904 places both at your fingertips. With it, you can build and test almost any popular HF tuning and matching network, plus many other useful circuits in minutes -- all without plugging in a soldering iron. The MFJ-5904 is packaged for portability with a compact molded case and high-quality internal components. In fact, each component is 300-watt ATU rated so you can put your network designs to the test under actual operating conditions using a 100-Watt station transceiver.
The MFJ-5904 provides two adjustable capacitor banks, each with variable and switched components to provide any value between 12 pF to 912 pF. It also provides a switched toroid inductor assembly that is adjustable from 0.1 to 11.2 uH in 12 steps. All tunable components are RF-isolated from the aluminum front panel to ensure personal safety. Simply connect patch leads to configure the circuit -- then tune in the optimize values for peak performance.
Fast setup times allow you to try different network configurations to see which one works best for your particular application. Here are examples of circuits supported by the MFJ-5904:
Single element matching, L and C
Series-L, Shunt-C (low-Z to high, low-pass)
Shunt-C, Series-L (high-Z to low, low-pass)
Shunt-L, Series-C (low-Z to high, high pass)
Series-C, Shunt-L (high-Z to low, high pass)
Pi-network (common in transmitters and amplifiers)
T-network (widely used antenna tuner circuit)
Notch (suck-out) filter, series L/C across signal path
Trap reject filter, parallel L/C in series with the signal path
Band-pass filter, parallel L/C with shunt-C, series-C input
Load converter (converts your 100-W 50-Ohm load to other values)
Selective field-strength meter
Portable antenna tuner
