Daniel, W6SPC, has a great idea for replacing electrolytic filter capacitors on the Drake R-4B receiver (especially pertinent now that Drake is phasing out servicing for its older gear and parts are becoming less available--Ed): Quad filter capacitors are scarce or no longer available, and the available space below the R-4B chassis rules out using four single capacitors. I installed four singles on a 5-pin plug in the place of the quad unit, however (see drawings, below), and it worked out just fine! A socket was installed in the old chassis hole and wired to connect to the replacement capacitors. Then, wire the individual capacitors to a mating 5-pin plug and you have a four-section filter capacitor. Older-style plugs and sockets like the 5-pin unit I used (or other pin configurations, such as octal--Ed) often are available very inexpensively at hamfest flea markets. The ground plate on the plug--used as the common or negative capacitor terminal--was cut out using the outline of the old capacitor mounting plate. A locking ring holds the plate in place. While I installed my unit in a Drake R-4B, this idea is applicable to any older gear that calls for a multiple-section filter capacitor can.--Daniel Mackintosh, W6SPC.