The AH-4 is enclosed in a weatherproof housing and is capable of being permanently installed outdoors. It interfaces to the radio with the coaxial feed line and a 4-conductor control cable. The cable carries the 12 volt power and ground, and the KEY and START control lines. Icom AH-4 HF+50 MHz Automatic Antenna Tuner Compatible with most Icom HF radios, including but not limited to: Icom 703, 703+, 706 MkIIG, 718, 746, 746Pro, 756, 756Pro, 756ProII, 756ProIII, 7000, 7100, 7200, 7300, 7410, 7600, 7800, 9100.
I buried a couple of coax runs from the shack wall to a spot about 15m away behind a large bush. The ladder line from the loop falls down to this spot so I do not have wires directly hanging off the house (which makes the YL happy). I was using a DX Engineering MAXI-CORE Balun and was happy with the results. (As an aside: I love hamfests! I picked up this used balun for a song.
Icom Ah-4 Control Cable
) I used this setup for a few years and have been pretty happy with the results.Since the loop is a non-resonant antenna, the SWR can be high. I've been using the tuners built into my transceivers (Elecraft K2 & K3) but have been concerned about loss in the coax. Since I only run 100 watts or less, I want every bit of power to get to the antenna and not be used to heat the coax. Placing a tuner at the end of the coax run is supposed to reduce the coax loss. I had always planned on adding a remote tuner when the budget allowed. When I buried the coax, I also threw in a couple of runs of CAT-5 cable that I had laying around for use for some sort of remote control.
The remote connection at the end of the coax run |
All connected and ready to go! |
Control Cable For Cars
The 'controller' in the shack |