MFJ Mobile Antenna Capacitive Matcher Thank you for purchasing the MFJ-909 Mobile Antenna Matcher. The MFJ-909 will lower SWR by capacitive matching a mobile antenna to 50 ohms. DESCRIPTION: HOOK-UP: Connect the antenna to the plug labeled OUT and connect the transmitter to the plug labeled IN. The cable from your antenna to the MFJ-909 needs to be as short as possible. Keep it under two feet. Also, keep the MFJ-909 out of the weather; either in the truck or in the cab of you vehicle. There are mounting holes provided. OPERATION: CAUTION: DO NOT switch positions while keying the transmitter. For each band, try switch position for minimum SWR. Select a position and key the transmitter while checking the SWR. Repeat this for each switch position. Remember not to change the switch setting while the transmitter is keyed. For easy reference later, make a chart with each band and what position gives minimum SWR. After selecting the switch position with minimum SWR for that band, recheck resonant frequency of the antenna and adjust it, if necessary, as the antenna may be detuned to a slight degree. CAPABILITIES: The MFJ-909 has 11 values of switchable capacitance from 30pF to 2000pF and can handle up to 600 Watts of power.