single strand sure makes wiring a big project a breeze, fragile? Ampeg V4 is packed with single strand, yet to see a busted wire, and this amp is used for bass a lot, must be quality wire,
now a chassis that uses wire wrap? pretty brittle, undo a few posts on a Marantz 2330 and tell me what happens? supposed to be more dependable that solder, used by Nasa in the old days, go figure,
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Wire wrap is a method to construct electronic circuit boards. Electronic components mounted on an insulating board are interconnected by lengths of insulated wire run between their terminals, with the connections made by wrapping several turns around a component lead or a socket pin. Wires can be wrapped by hand or by machine, and can be hand-modified afterwards. It was popular for large-scale manufacturing in the 60s and early 70s, and continues to be used for short runs and prototypes. The method eliminates the design and fabrication of a printed circuit board. Wire wrapping is unusual among other prototyping technologies since it allows for complex assemblies to be produced by automated equipment, but then easily repaired or modified by hand.
Manual wire wrapping/stripping tool and wire in various colours
Wire stripper for AWG 30
Mechanical wire wrap tool
Electrical wire wrap tool
Manual tool to open a wire wrap connection
Wire wrap construction can produce assemblies which are more reliable than printed circuits: connections are less prone to fail due to vibration or physical stresses on the base board, and the lack of solder precludes soldering faults such as corrosion, cold joints and dry joints. The connections themselves are firmer and have lower electrical resistance due to cold welding of the wire to the terminal post at the corners.
Wire wrap was used for assembly of high frequency prototypes and small production runs, including gigahertz microwave circuits and super computers. It is unique among automated prototyping techniques in that wire lengths can be exactly controlled, and twisted pairs or magnetically shielded twisted quads can be routed together.
Wire wrap construction became popular around 1960 in circuit board manufacturing, and use has now sharply declined. Surface-mount technology has made the technique much less useful than in previous decades. Solder-less breadboards and the decreasing cost of professionally made PCBs have nearly eliminated this technology.
A correctly made wire-wrap connection is seven turns of bare wire with half to one and a half turns of insulated wire at the bottom for strain relief.[1] The square hard-gold-plated post thus forms 28 redundant contacts. The silver-plated wire coating cold-welds to the gold. If corrosion occurs, it occurs on the outside of the wire, not on the gas-tight contact where oxygen cannot penetrate to form oxides. A correctly designed wire-wrap tool applies up to twenty tons of force per square inch on each joint.
The electronic parts sometimes plug into sockets. The sockets are attached with cyanoacrylate (or silicone adhesive) to thin plates of glass-fiber-reinforced epoxy (fiberglass).
The sockets have square posts. The usual posts are 0.025 in (0.64 mm) square, 1 in (25.4 mm) high, and spaced at 0.1 in (2.54 mm) intervals. Premium posts are hard-drawn beryllium copper alloy plated with a 0.000025 in (630 nm) of gold to prevent corrosion. Less-expensive posts are bronze with tin plating.
The two holes at the end of a manual wire wrap tool. The wire goes in the one near the edge, and the post is inserted into the hole in the center
30 gauge silver-plated soft copper wire is insulated with a fluorocarbon that does not emit dangerous gases when heated. The most common insulation is "Kynar".
