16 April 2023

Behold The Lowly Tuner

Antenna tuners* get little love. Every ham needs one, most have at least one, but they rarely get talked about in glowing terms, like a good radio, or great antenna design, or a fine cigar. Instead they are viewed mostly as lumps - lumps of metal or plastic that sit nearby and make sure the finals on your precious $2,000 radio don't burn up because you keep trying to put a 100 watt full duty cycle signal into an antenna that's a 10:1 mis-match.

The tuners built into most radios designed for Amateur Radio use are pretty anemic - handling (at best) a 4:1 mis-match. About all they'll do is lightly tweak a nearly resonant antenna. There are exceptions, like the internal tuners Elecraft builds for it's KX line of QRP radios. These remarkable units can tune the bumper on my wife's Hyundai. And I have to admit, Chinese manufacturers like Xeigu have put very good tuners in their radios almost from the beginning. This begs the question - if the Americans and Chinese are building really good internal tuners for their radios, why can't the Japanese? Has advanced tuner technology not made it across to that part of the Pacific rim yet? Geeze.

There is a single tuner that keeps popping up whenever I need to run a portable HF radio at 100 watts with a sub-optimal antenna. I've had it for several years, and bought it when I owned a Yaesu FT-891. I wanted something that could run off of batteries and handle just about any antenna I hooked up to it. This tuner worked great with the FT-891, and when I needed a tuner for an FT-991A it worked great for that, too. Then I got my hands on an Icom IC-7200, followed by an IC-7100, and guess what? It worked great with those radios. When I got my IC-705 and didn't want to pay Icom's outlandish price for the AH-705, I saw Ham Radio Outlet (HRO) was offering my tuner in a 'special IC-705 configuration'. I emailed the manufacturer and asked what made the tuner 'special'? In about an hour I got an answer back - all HRO was doing was bundling the tuner with a 3.5mm audio jack cable, to serve as the control connection between the radio and tuner. Like most hams, I had a several 3.5mm audio jack cables laying around. I hooked the tuner to the 705 and, sure enough, it worked! Seems the tuner was '705 ready' before the 705 was even a glimmer in Icom's eye. 

Most recently, I've begun testing the Icom IC-7300 for use as a field radio and needed a tuner that could handle antenna mis-matches greater than 4:1 (about the limit of the 7300's internal tuner). Once again, I grabbed this tuner and it worked great.

Recognize the tuner? It's the LDG Z-100 Plus. It's an unlovely lump - just a black metal box with some LEDs and a tune button. But what it lacks in aesthetics it makes up for in performance and versatility. It's relatively compact, runs on internal power (via a AA battery tray mounted inside), is rugged, reliable, fairly priced, and has tuned just about everything I've hooked up to it. 

The Z-100 Plus with an ID-52 for size comparison. Sorry for the goofy color balance - I
shot the tuner on a green tray, underneath a red umbrella. The sensor in my camera
must have gone nuts trying to get it all balanced out

LDG offers Icom and Yaesu specific cables for this tuner so they'll interface with your rig - hit the tune button on your radio and the Z-100 Plus wakes up and runs a tune cycle. The tuner will also work with just about any other radio by putting out a low power CW carrier and tapping the Tune button on the tuner. If there's any weakness in the system it's in the Icom control cable (which works with any tuner in the LDG line). I've gone through three due to broken or poorly crimped pins on the Molex connector that mates with the radio. Thank goodness the cables are reasonably priced. My advice is, if you are going to use this with an Icom rig, have a spare cable (or two) on hand.

Operating off grid? No problem. Just stuff a handful of AA batteries into the internal tray

If you are looking for a compact, internally powered 100 watt tuner with a proven track record that will interface neatly with Icom and Yaesu radios, check out the Z-100 Plus. LDG as a company has been around for a long time and they make quality products. This tuner may not be much to look at, but it performs great and is as reliable as a hammer. Almost as heavy as one, too.

*Ok, ok, ok, antenna tuners don't tune antennas. They just make the antenna look like a 50 ohm match to the transceiver. But 'tuner' is the commonly used descriptor for what we're talking about here, so we'll use it.

W8BYH out

No comments:

Post a Comment