Cobra 19 Plus

1.	Remove the covers from the unit and locate jumper wire SJ7 just behind the LC7131 PLL chip. Cut this jumper and solder the expanders Green wire to the cut wire nearest the PLL chip. Solder the expanders White wire to the other side of the cut. If interference from the normal channels interfere with the extra channel receive, a 22 pf capacitor may have to be soldered in series with the Green wire.
2.	Solder the expanders Red wire to the switched side of the volume control (+13.8 VDC).
3.	Solder the expanders Black wire to circuit board ground.
4.	Solder the small 100 pf capacitor (included in kit) across the outer terminals of filter CF-1. (Next to L103). If a squealing noise is encountered on receive, solder a 1k resistor in series with a 22 pf capacitor, and solder them across the outer pins of CF-1. (reeve off the 100 pf cap above) See Uniden PC-33 for more details..

* Tum the unit on and verily transmit on all Extra channels. If the expander does not work on all channels a slight adjustment of the VCO coil may be necessary. Tune the unit to channel 40 on the extra channel side, and tune coil L102 for maximum receive. Next tune the unit to channel 10 and tune coil L103 for best compromise position. Notice that coil is tuned best for normal channels at one position, and best for extra channels at another position. By flipping switch back and forth, and tuning L103, an adjustment can be made.