5.2 INSTALLATION OF ACCESSORIESm REMOVING THE CABINET (See Fig. 5-1)Figure 5-1 illustrates cabinet removal. Remove the eighttop-cover and eight bottom-cover screws and lift away thepanels.NOTE:This product uses metric hardware.CAUTION:The speaker lead is attached to the chassis, so be carefulwhen removing the top-cover.The lead can be unplugged, if necessary.Fig. 5-1 Removing the Case@ OPTIONAL FILTER INSTALLATION1. Using a number 2 Phillips screwdriver, remove thetopcover (eight screws). Unplug the speaker and setthe cover aside.2. Remove the bottom cover (eight screws)3. Remove the six screws holding the IF unitX48-1310-00 and swing the printed-circuit boadover.4. Using a 45-W (or less) soldering pencil, clear the sixholes for the filter, if they are filled with solder.5. YK-88S, C or CN there is no polarity to the filter. In-stall the filter into its position on the IF unit. Solderthe two mounting tabs and the four input and outputpins to the circuit boards. Solder sparingly, and heatthe connections only long enough to insure a goodsolder joint.Don’t overheat the filter or circuit board.6. Carefully inspect your soldering. Be certain that allpins are actually soldered, and that you have not sol-dered across any spots on the board or between anyof the pins on the filter. Clip the pins flush to theboard.7. Replace the IF unit. Make certain no wires will bepinched underneath the board. Replace the sixscrews.8. More the A and B connectors as illustrated, followingTable 5-1.9. Reinstall the bottom cover. Reconnect the speakerlead, and reinstall the top-cover.10. Apply power and verify your work. Filter installation isnow complete.CW FILTER YK-88CYK-88CNcSSSB NARROW FILTER] yk-88SN@ When two CW filters, YK-88C andYK-88CN are used, mount the YK-88C inthe SSB NARROW FILTER position andthe YK-88CN in the CW FILTER posi-tion.Jumper connectors A and B (as shown)according to the optional filters used.\ Fig. 5-2 Filter installationA OBSSN CWI SsBJumperOptional connectorFilterYK-88XX AWithoutfilter cwoptional* denotes no reception.Table 5-1 Optional Filter SelectionIntransmission,theSSB(WIDE)filterisused regardlessofMODEorNAR-WIDEswitchpositions.m@ VFO-230, VFO-240 CONNECTION (Fig. 5-3)Connect the VFO-230 or VFO-240 as shown.VFO-230 orVFO-240 TS—530Fig.5-3 VFO CONNECTION23