SGC SG-230 Smartuner
$$···
| Frequency | 1.6 - 30 MHz (160 through 10 m) |
| Bands | 160m, 80m, 40m, 30m, 20m, 17m, 15m, 12m, 10m |
| Power | Automatic external tuner rated about 3-200 W PEP (around 80 W continuous). Tunes random wires (from ~2.4 m) and whips - a 23 ft whip covers 1.6-30 MHz, a 9 ft minimum whip covers 3-30 MHz. |
| Modes | weatherproof external/remote automatic antenna coupler (for wire and whip antennas) |
| Weight | 3.6 kg (7.9 lb) - About 8 lb (~3.6 kg); 16 x 12 x 3.5 in (41 x 31 x 8 cm) waterproof case. |
| rf input | Coax (SO-239) from the transceiver, run out to the tuner at the antenna |
| antenna | A terminal for the wire or whip antenna element (and a ground connection) |
| dc in | 13.8 V DC at about 900 mA (the control line runs alongside the coax) |
| power req | 13.8 V DC, ~900 mA. Mounts outdoors at the antenna feedpoint; non-volatile memory keeps tuning settings without power. |
A purpose-built outdoor auto-coupler: mount it at the antenna and it automatically matches a random wire or whip across all of HF, storing 500 settings for instant recall. Its waterproof case suits permanent rooftop, marine and mobile installs, it tunes very high impedances that shack tuners struggle with (because it sits at the feedpoint), and it earned a strong reputation for reliability in commercial/marine service.
SGC has gone out of business, so it is effectively a legacy/used-market product with no factory support. Power is limited (~200 W PEP, 80 W continuous), it needs a 12 V control feed out at the antenna, and as an end-fed-wire coupler it relies on a good ground/counterpoise to work well. It is an antenna-mounted coupler, not a shack tuner with a meter.
The SGC SG-230 Smartuner is a classic weatherproof, antenna-mounted automatic coupler that matches wires and whips across 1.6-30 MHz with 500-memory recall - ideal for permanent outdoor, marine and end-fed-wire installations up to ~200 W. With SGC now defunct it is a used-market choice; for new auto tuners look at current makers, but a working SG-230 remains highly capable.
The SGC SG-230 Smartuner is an automatic antenna tuner of a different kind from a shack tuner: it is a weatherproof 'coupler' designed to mount outdoors, right at the base of a wire or whip antenna. Putting the tuner at the feedpoint - rather than back in the shack at the end of a long coax - lets it match the very high and reactive impedances that end-fed wires and whips present, across the whole HF range from 1.6 to 30 MHz. You run coax and a 12-volt control line out to it, attach your wire or whip, and it tunes itself.
Inside, a microprocessor drives a pi-network with up to 500,000 possible element combinations and stores the results in 500 non-volatile memories, so once it has matched a frequency it can recall the settings almost instantly even after power has been removed. It tunes random wires from about 2.4 meters up to tens of meters; a 23-foot whip covers the full 1.6-30 MHz, while a 9-foot whip works from 3 MHz up. It handles roughly 3 to 200 watts PEP (about 80 watts continuous) from a 13.8-volt supply at under an amp, all in a waterproof ABS case about 16 by 12 by 3.5 inches and 8 pounds - built for permanent rooftop, marine and mobile installations.
The major caveat is that SGC has gone out of business, so the SG-230 is now a legacy, used-market product without factory support. Power is limited to around 200 watts, it needs that outdoor 12-volt feed, and like any end-fed coupler it depends on a good ground or counterpoise. As an antenna-mounted coupler it also has no front-panel meter. Even so, a working SG-230 remains a highly capable, rugged auto-coupler.
It is an outdoor-coupler alternative to radio-specific auto tuners like the Icom AH-4, and to shack auto tuners such as the LDG AT-1000ProII.