TitleWhirlwind vacuum tube module rack
|Other number||01819||Stamped in blue ink on a white label stuck near BNC connector J4-2 on the top channel of the rack.|
|Other number||01975||Stamped in blue ink on a white label stuck near BNC connector J9-3 on the bottom channel of the rack.|
|Other number||E12-9||Written in ball point pen on a sticker stuck to the left end of back of the upper channel of the rack.|
|Other number||PIUMP #256||Engraved white on black on a plastic label attached upside down to the right end of the lower channel; a black unprinted Dymo label covers part of this number.|
|Serial number||256||Stamped in white ink on the left end of the upper channel of the rack.|
Dimensionsoverall: 7 3/8 in x 26 in x 12 1/2 in
DescriptionThe rack is built around two identical frame members consisting of a piece of heavy metal that is bent up along one side and down along the other, resulting in an 'N'-shaped channel with a 1.75" bend up, a 2.25" horizontal surface, and a 0.625" bend down. Two of these, oriented in opposite directions, are held together with ten 24-contact edge connectors into which two-tube modules are inserted. Two 11-position screw terminal strips also span the two channels on the right side of the front. Twenty round holes to accommodate BNC connectors are drilled along the front of both channels; however, not all the holes are populated. On the back of the rack, phenolic boards with several rows of solder terminals are mounted to the horizontal sections of each channel, and another phenolic board with two rows of solder terminals is mounted perpendicular to each of these. Two 5-position screw terminal strips are mounted on the left side of the back of the rack, and one 4-position screw terminal strip is mounted to the bottom of the left end of the bottom channel.
About 7 long bus wires are connected to pins of the module sockets to supply common signals and voltages. The two horizontal boards are also wired with two busses each. The vertical boards attached to the horizontal boards hold the passive components of the rack. Wiring is point-to-point between the solder posts of the boards and the terminals of the module sockets. Some of the wiring terminates at the screw terminal strips. Many of the external wires connected to the screw terminal strips have been cut.
Three brackets that hold two neon lamp sockets each are mounted to the upper phenolic board. Each pair of sockets has a red lens and a clear lens. It appears there were Dymo labels mounted below each pair of sockets, but they are no longer there; thus, a '0' and a '1' are printed in white below the sockets.
Six BNC connectors are mounted in the 20 holes along the top of the rack. Cables that are cutoff are attached to two of the BNC connectors; a BNC tee and two cutoff cables are attached to two of the connectors, a BNC tee, a terminator, and a cutoff cable are attached to one; and one BNC connector has nothing attached to it. Ten of the holes along the bottom of the rack are populated with BNC connectors. Three of the connectors have a BNC cable that has been cut off attached, five have a BNC tee, a terminator, and a cut-off BNC cable attached; and two have a BNC tee and two cutoff cables attached.
A paper tag is attached with string to the hole for BNC10-1 that says "9C ACA Sept 2/58" written in blue ball point pen.
All module locations are occupied by 2-tube plug-in modules, and they each have a tag attached with handwriting in pencil. The module model, serial number, and tag inscription are, from left to right: BA BA# 228, "E12-9-1"; FF#871, "E12-9-2"; GT BA# 1201, "E12-9-3"; GT BA# 1243, "E12-9-4"; BA BA# 156, "E12-9-5"; BA BA# 376, "E12-9-6; GT BA# 347, "E12-9-7; FF# 1008, "E12-9-8; FF#302, "E12-9-9; and GT BA# 1205, "E12-9-10". One of the modules is missing a vacuum tube.