MFJ-929, 200W AUTO TUNER, LCD/MTR, 1.8-30MHz

Technical Description MFJ-929

The MFJ-929 is a very fast automatic tuner for coaxial fed antennas. It has two switchable antenna connectors, the LC display on the front panel provides information about the operating status. If desired, tuning can also be done manually using the keys on the front of the tuner. For many radios, control cables are available that allow tuning via the radio (tune button).

The tuning range of the MFJ-929 is 6 to 1600 ohms, which corresponds approximately to an SWR of 32:1! Eight coils and eight capacitors are used for tuning, which allows a very fine resolution of the L and C values. Once adjustments have been found, they are stored in the memory, thus considerably shortening the tuning process the next time. The memory is divided into four banks to distinguish different antennas on the two available ports. The LC display shows SWR and power, also as an easy-to-read bar graph. The maximum allowed transmit power is 200W SSB PEP, the minimum drive power is 2 Watt. The tuner requires an operating voltage of 12 to 15V, the current consumption is approx. 850 mA.

Application Description MFJ-929

The MFJ-929 can be easily integrated into the existing station with the optional control cables. This makes fully automatic operation possible without any problems, even at a remote-controlled station. The fast tuning ensures good matching with a wide variety of coaxial cable-fed antennas. The two switchable antenna connections allow different antennas to be combined, even if the transceiver has only one connection. The uncomplicated setup and operation is done via buttons on the front panel. Together with the easy-to-read LC display, this gives you the opportunity to learn something about the operation of the antennas – is more C or more L necessary, what impedance is the tuner measuring at the moment? Because the MFJ-929 tuner works as an SWR and wattmeter, you always have the most important parameters in view. And if you wish, you can also set L and C manually, which is helpful, for example, if you want to adjust an antenna outside the transmission ranges just for listening.

Another nice feature is the acoustic SWR warning, the threshold value is adjustable. This way you get an immediate warning if something has changed on the antenna, for example a wire that has come loose in a storm.