The typical "Kofferaufbau" has 5 antenna ports. These ports accept the AB-15 antenna base which in turn hold AB and MS series mast sections. The AB-15 consists of (from top to bottom) a flexible top section, top ceramic insulator, gasket, grounding ring, another gasket, and a bottom ceramic insulator assembly. The bottom insulator assembly is made up of the ceramic insulator and SO-239/threaded rod combination. The bottom insulator "nests" inside the top insulator. By threading the top section onto the bottom section rod, the rims of the two insulators are clamped to the antenna port. Some AB-15s have an adaptor which threads onto the SO-239 connector and allows the use of a single wire or coaxial cable center conductor to feed the antenna.

	The AB-15 accepts AB and MS series antenna mast sections. The MS series sections (MS-116, 117, 118) are each about 1 meter (~39" ) in length and thread together to form a vertical antenna from 2 to 5 meters long without support, though at 5 meters the antenna likes to lean to the side. The MS-118 top section threads into the MS-117 mid section, which can be threaded into multiple MS-116 bottom sections, or directly into the AB-15.
	The AB series sections (AB-21, 22, 23, 24) are each about 24" in length and thread together to form a vertical antenna from 4' to 8' long. The AB-24 top section threads into the AB-23 or AB-22 mid sections, which can be threaded into multiple AB-21 bottom sections, or directly into the AB-15. With the AB series masts, antennas from 4' on up can be assebled in 2' increments. For most Amateur radio applications an antenna tuner is needed between the transceiver and the antenna. The tuner pictured here covers 1.8 MHz thru 54 MHz. It works with 8' and longer antenna whips and thus does quite well with AB and MS antenna sections. For operations on the lower Amateur bands (3.5 to 14 MHz), I use the MS sections to create 4 to 5 meters of whip. If I plan to work around 50 MHz, then I use the AB sections to create an 8' whip. Even this "short" antenna performs quite well on the lower bands. The tuner is mounted under the left rear antenna port on a bracket designed to hold, you guessed it, an antenna tuner (my Mog came with three of these brackets). The output of the tuner connects to the "adaptor" by a 12ga. copper wire.
		Send comments and mail to Ed Wright, kb6tho@pacbell.net Copyright 2000 The Mountain Repeater Association Last updated by Ed, KB6THO on 4/1/00