160m-6m

Bands

125 W

Rated

Frequency	1.8-54.0 MHz
TX power	125 W (SSB 1-125 W; CW 100 W; FT-8 75 W; PSK/digital 50 W; 6 m 50 W. Tunes from 1 W. Vacuum-tube transmitters cut the ratings roughly in half. Switched-L network with latching relays)
Modes	all
Weight	595 g (21 oz)

Connectors

tx in	SO-239 (from radio)
ant out	ANT1 + ANT2: two SO-239 (2-position switch)
radio	optional tune-cable jack
dc in	11-16 V DC
power req	11-16 V DC @ 500 mA (7 mA idle); latching relays hold the match when powered off

A 125 W automatic switched-L tuner, 1.8-54 MHz - LDG's standard barefoot-station tuner Power: SSB 1-125 W, CW 100 W, FT-8 75 W, PSK/digital 50 W, 6 m 50 W; tunes from just 1 W Matches 6-1000 ohm (16-150 on 6 m); dipoles, verticals, inverted-vees, virtually any coax-fed antenna 4,000 memories (2,000 per antenna port) and a built-in 2-port antenna switch Latching relays hold the tuned match indefinitely with power off, and draw almost nothing idle (7 mA) LED bargraph (12.5 W / 125 W scales) with antenna-select and bypass LEDs; Auto/Semi mode 7.5 x 5.5 x 2.25 in, 1 lb 5 oz; 11-16 V DC @ 500 mA; external balun needed for ladder line

Strengths

The natural automatic tuner for a 100-watt radio: 125 watts (100 CW, 75 FT-8, 50 digital), 4,000 memories, a two-antenna switch, and tuning from just 1 watt, in a compact, affordable box. Latching relays hold the match with power removed and sip almost no current, so it suits battery/portable use too.

Weaknesses

It is a 125-watt tuner only - not for amplifiers - and like all switched-L designs it clicks while tuning and must tune at low power. It needs its own 12 V supply and an external balun for ladder-line. Confirm LDG's current warranty support, as the company is small.

Verdict

LDG's bread-and-butter auto-tuner for the 100-watt station: cheap, compact, 2,000 memories, two antennas, and tuning from 1 watt. For a barefoot rig into coax antennas it is an easy recommendation; the 250 W AT-200ProII adds power and the battery-capable Z-11ProII suits QRP/portable use.

The LDG AT-100ProII is LDG's standard automatic tuner for the 100-watt station - the most common power level in amateur radio. It is the familiar microprocessor switched-L design, rated to 125 watts and able to tune from as little as 1 watt of drive, covering 1.8 to 54 MHz and matching dipoles, verticals, inverted-vees, and virtually any coax-fed antenna.

It carries 2,000 memories for instant band changing and a built-in two-position antenna switch, and the ProII revision added small conveniences: an LED to show which antenna is selected and another to indicate bypass. It is a standalone unit running on its own 11-to-16-volt supply, though optional cables let it tune directly from many radios' TUNE buttons.

Its limits are simply those of the class: 125 watts means it is a barefoot tuner, not for amplifiers; it clicks while the relays search; and it must tune at low power and wants an external balun for ladder-line. For a 100-watt rig feeding coax antennas it is an inexpensive, reliable set-and-forget choice. The AT-200ProII is the 250-watt step up, and the battery-capable Z-11ProII is the QRP/portable sibling. As always with LDG, confirm current warranty support.