Be on the air with just some meters of wire! Can be used with reduced efficiency up to 150 MHz
Principle of operation:
Usual internal tuners or external tuner only have a limited impedance range. The matching of a short wire (short in comparision to the wavelength) with it's high impedance is usually not possible.
Futher the wire is usually outdoors, the tuner sits in the shack, but the wire cannot be connectied to the tuner with a coax feed... Here a wire tuner like the SGC products will help - at a price!. But there is a more economic alternative.
The MTFT is a resistance transformer with a ratio of 1:9. It reduces the extremely high impedance of a short wrie to a range which can be matched with a normal tuner. The balun must be used right at the antenna wire, don't use coax to feed the wire. The MTFT is then connected with a coax to the tuner, the SWR on this line is usually below 3:1, losses through resonant waves are low.
The required wire length should be at least 6m. Ground connection is good, conenct ground with a clamp to the ground of the PL connector, not to the insulated case. If no ground can be used at the balun at least the transceiver should be grounded. If necessary use a common mode filter right below the balun. Instead of a ground connection a counterpoise can be used.
Transformation Ratio 1:9
Type of balun Voltage Balun
Max. Power [W] 100 W
Frequency Range 1 - 50 MHz