Amatuer Radio Blog

PALSTAR HF-Auto review

I have been using my new HF-Auto and LA-1K, for over a week now and this is a good point for an initial equipment review. I will start here with the HF-Auto and follow up with the LA-1K in another posting.

The LA-1K HF Stepper tuning Network is quite a substantial antenna tuner. A purist would call it trans match, since all these really do match your antenna’s impedance at any given frequency to your transceiver’s nominal 50-ohm impedance. That is ok, but antenna tuner seems to work fine as a label for most. This beast measures 12.5” x 6.5” x 16.5,” not exactly compact, and weighs 20lbs.

Inside the unit you can see its huge butterfly capacitor, and large rotary coil. A rotary coil is usually found only in higher quality manual tuners. The advantage of these variable capacitors and inductors vs switched discrete capacitors and inductors is that a precise match can always be obtained. A switched cap and coil arrangement with either panel knob switch or via an automatic relay system is limited to the values of discrete capacitors and inductors that the tuner has. They usually can get a close match that is sufficient for most purposes, but the rotary design, being continuously variable, can always hit the nail on the head.

As mentioned in earlier posts, the new LA-1K amplifier made apparent the need for an antenna tuner capable of handling its greater power. This narrowed the field of candidate tuners and my desire for an automatic tuner limited it even more to just three devices. The first two choices were the MFJ-998, and the LDG-Pro1000 II. Both the LDG and the MFJ are of the relay type – these tuners make clacking noises as they evaluate different capacitance and inductance values to find the best SWR match. I’ve no problem with these types of tuners, and in fact my current tuner is an MFJ-939, of a similar design, albeit limited to 200 watts power capacity.

However, I am now soured on MFJ products lately. Not that they do not produce useful equipment, but that their quality control leaves a lot to be desired. I recently purchased a brand-new wattmeter/dummy load from them that had a rattle. I opened the unit up and found a loose screw. There were no missing screws anywhere in the unit, so this was likely something dropped into the unit during assembly. While buttoning things up I noticed the soldering could have been better, and the screen printing on the case was a bit skewed. This points to cutting corners with the product. If a $200 wattmeter/dummy exhibits such issues, imagine just how worse things could be with a unit costing three or more times that much and designed for high power? I do not want to go there.

With MFJ out of the running, the LDG-1000Pro II was still on the table. LDG is somewhat of an unknown, but I have no knowledge of any serious quality control issues with them. Their tuner can manage 1000 watts of the LA-1K, but there is no safety margin. The LA-1K (actually) can put out up to 1200 watts on most bands. The only other manufacturer of antenna tuners that can manage such power was PALSTAR, who has several capable models. PALSTAR only makes one automatic tuner, though, and that is the HF-Auto. It is unique in that it is the only automatic tuner on the market that uses a rotary capacitor and a roller coil inductor. It also costs about twice as much as its nearest competitor, the MFJ-998. The difference in quality is legion, though.

The HF-Auto has a large LCD display. On it are displayed its current mode; auto or manual, the current L and C values, peak power, and SWR. It also indicates which of the three available antenna ports is currently active. Great, no need for external antenna switch if you are using more than one antenna in your setup. There is a power switch (13.8VDC required), mode and antenna buttons, and menu buttons. There is little to setup, though You really need only to set its tune-up power limit. I set mine to the smallest value of 100 watts, since it is never a good idea to tune with high power. You do this by using the menu key to bring up the selection for tune-up power. Easy.

Operation of the HF-Auto is simple. In normal use, when tuning to a new frequency, you apply about 20 watts of carrier (either AM, FM, or CW/key-down) for second and the tuner will preselect a reasonable starting from which to tune, or if it has memorized this frequency from a past tune, it will use the memorized settings. You will hear its internal stepper motors turning with a slight whirring noise. It is quite a satisfactory sound. After it stops (a few seconds), you then key again a second time while watching the panel. If it has a match, no further tuning will take place and you can see the resulting SWR, the power output, and the L and C positions being used.  If further tuning is needed, you will hear it whirring again as it settles on a match. It will remember its L and C setting so that the next time you tune on the same frequency, it will go directly to those values, so the second key-up simply confirms it for you.

This is normal tuner operation in a nutshell – two brief key ups. You do have the option of placing the unit in manual tune mode to further touch up the LC solution. This is done by pressing the mode button and then turning the center dial to adjust. ‘Press’ the center dial to toggle between L and C. You can also store the touched-up solution as well for the current frequency. With your antenna tuned, you can now run higher power. You might see a very slight increase in SWR with higher power. This is normal though; at match reflected power is negligible and barely measurable at all. I can easily achieve a 1.05 to 1 match. It is not uncommon to see it then peak at 1.15 to 1 at 600-700 watts or greater of SSB PEP power. This is trivial, though.

I am impressed. The HF-AUTO gives me the accuracy of a manual tuner, with the ease of an automatic tuner. All that, and it can manage a whopping 1800 watts of power, which means that it will loaf along with the LA-1K unable to perturb it. The LA-1K will run cooler as it sees a perfect impedance match. Truly, its only real fault is its price, but it can command that since it is currently the only one of its kind on the market.

On a last note, I have seen a posting online elsewhere where someone bemoaned PALSTAR’s industrial design “looks.” Well, I agree, it is no “Flex Radio” with its euro-industrial looks, but then it is not trying to be. It has a smooth black iridized matte finish with clean screen-printed labeling. Genuinely nice looks. A Flex Radio in contrast looks like it is trying too hard, like a “neon” water softener or something. All for a box that needs nothing more than an on/off switch on its front.

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