Note
The MFJ-939 Plug&Play Intellituner is simple-to-install antenna tuner for use with Icom, Alinco, Kenwood, or Yaesu radios. The unit comes complete with interface cable and programmed for your particular radio.
The IntelliTuner lets you rapidly tune any unbalanced or single-wire antenna
automatically. "InstantRecall" and "AdaptiveSearch" algorithms give you
fast automatic tuning with more than 20,000 non-volatile memories.
The tuner includes a highly efficient switching L-network with wide matching capability, 1.8 to 30 MHz coverage, a radio interface port, and heavy-duty 10 amp/1000 volt relays. It is rated at 200 watts SSB/CW.
A maximum of 256 values of inductance and 256 values of capacitance are available. With the capacitance switched between the input and output side, this provides a total of 131,072 L/C tuning combinations. The nominal tuning ranges are 0 to 24 μH and 0 to 3900 pF.
The IntelliTuner learns and remembers. When you transmit, it automatically
adjusts for minimum SWR and remembers the frequency and tuner settings, safely stored in non-volatile memory. The next time you operate on that frequency (or close to it) and antenna, the tuner settings are instantly restored and you’re ready to operate in milliseconds.
The antenna has two sets of four banks of memory, which can learn and remember more than 2500 frequencies and tuner settings. A total of 20000 settings. When you key your transmitter, the tuner checks its memory to see if you have operated on that frequency before. If so, tuning is instantaneous and you’re ready to operate. If not, an algorithm (based on MFJ’s SWR Analyzer technology) kicks in. It measures the complex impedance of your antenna. Next, it calculates the components it needs and instantly snaps them
in. Finally, it fine-tunes to minimize SWR, and you’re ready to operate – typically in a fraction of a second.
If the antenna impedance is not within the tuner’s measurement range, the algorithm goes into action. Frequency is measured and relevant components values are determined. Only those values are searched for fast tuning. If it still cannot find a match, the search is performed again using a different search pattern.
The minimum power to tune is approximately two watts, with maximum SWR tuning accuracy occurring at tuning power levels of 10-20 watts.
The MFJ-939 supports radio tuner interfaces that are compatible with
Alinco EDX-2 tuner, Icom AH-3 and AH-4 tuners, Kenwood AT-300 tuner, Yaesu FC-30 tuner, and Yaesu FH-1 and FH-2 remote controls.
The MFJ-939 can be changed from one radio model to another with optional interface cables: MFJ-5114A (for Alinco), MFJ-5114I (for Icom), MFJ-5114K (for Kenwood); and MFJ-5114Y/Y3/Y4 (for Yaesu).
The tuner enters a “sleep” mode when idle and when no transmit signal is present, turning off the microprocessor clock to avoid the generation of spurious signals.
