Antenna Tuners

I'm considering the purchase of a couple of antenna tuners to add to my station. Currently, my Kenwood TS-2000X has its own built-in tuner and I add a LDG Electronics AT-897 to my Yaesu FT-897D. I noticed recently that LDG has released a new autotuner dedicated to Kenwood transceivers. This model is the KT-100. It is similar to LDG's other autotuners in that it can tune across a wide range of impedances. This is something that the TS-2000's internal tuner cannot do. Its tuner has a fairly narrow range. The inability of the Kenwood tuner to find a successful match many times is what leads me to use the FT-897D on the HF bands. With the KT-100, however, I should be able to use the TS-2000 much more often. I do have a commercial Buddipole antenna and a Palstar ZM-30 antenna analyzer, and so I try to first make adjustments to the Buddipole (the taps on the coils and the lengths of the whips), but sometimes this is inconvenient, so I hit the tune button on the radio. Of course, I realize that by not making adjustments to the Buddipole, and letting the autotuner make the match that I am losing quite a bit of energy in the tuner.

Another tuner that I am looking at is the Palstar AT2K. This is a full legal limit manual antenna tuner. Like the LDG tuners, it can match antennas over a wide range of impedances. There are several reasons to consider a manual antenna tuner (and one that can handle higher power). First, by virtue of the tuner being manual, you can dial in the match exactly. Most autotuners, but not all (notably the Palstar AT-AUTO which uses stepper motors to drive conventional variable capacitors and variable inductors), rely on discrete capacitors and inductors and a number of relays to switch those capacitors and inductors in and out of the circuit. This will mean that the match will always be close, but not quite on. Also, some of the autotuners won't even run through a new tuning cycle if the SWR starts out less than 1.5:1 (although you can usually force them to re-tune). The second reason to consider a manual tuner is when you are only receiving. Your radio will not broadcast a carrier for any tuner if you outside of the ham bands (unless you have performed some sort of mod). When you are shortwave or utility listening, you can still use a manual tuner and tune for the strongest signal. A third reason that I see to purchase a manual tuner, but specifically the Palstar AT2K, is that the tuner is overkill for the power levels I will be using (barefoot at 100 watts or less). From some of my reading, it appears that under certain conditions, tuners can start arcing over. I suspect that arcing is more of a problem for stations running QRO, but it is probably also a problem in a small autotuner when running 100 watts because the autotuner's components are not rated for the really high voltages and currents involved. Finally, the fourth reason to consider a manual tuner, is that it doesn't care what radio it is connected to. All you have to do is put it in line between the transceiver and the antenna. With an autotuner, you more than likely need a dedicated set of cables for each radio that you are going to connect it to. If it doesn't rely on control cables, then it requires you to supply the carrier first, and then you hit the "tune" button. Of course, the main drawback to a manual tuner is that it takes more time to make the necessary adjustments.

Down the road, when I buy my Icom IC-7000, I will probably pick up a LDG AT-200Pro. I realize that LDG manufactures the AT-7000 specifically for the IC-7000, but quite frankly, the AT-200Pro has more lights and buttons. However a more appropriate reason to choose the AT-200Pro over the AT-7000 is that you can manually adjust the capacitance and inductance values (based on discrete components, though) on the AT-200Pro and improve shortwave reception.

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