Per usare antenne verticali di varie lunghezze (in particolare con canna da pesca) con gli accordatori d'antenna.   Esso può essere usato anche senza accordatori con verticali risonanti e per tutte le applicazioni che richiedano un UNUN.   Si istalla alla base delle antenne verticali.

• Weight: 6 oz (with enclosure)
• Configuration: 4:1 Unun
• Frequency Coverage: 1.8 to 30 MHz.
• Power Range: to 200 watts PEP.
• Easy to weatherproof.
• Enclosure size: 5 x 2.5 x 1.25 (measured in inches)

The RU-4:1 Unun was designed to allow easy interface of LDG S9 vertical antennas to the LDG line of Automatic Antenna Tuners. The 200 watt Unun also operates stand alone, thus does not require an LDG Tuner for resonant verticals. It may also be used with many of your antenna projects where a 4:1 Unun is needed.