av_wiring Audio-Video WIRING (Throop Memorial Church) by David Lawyer, Sept. 1993. Revised June 1996, Nov. 2001 HENRY HOUSE: There are at least 6 junction boxes there. See the file henry... The AV (Audio-Video) wiring at Throop consists of two basic systems. One is the system of old multi-conductor cables (not in conduit) and junction boxes installed by Robert Gratton and others in the 1960's. The other is the cables installed in a plastic conduit running under the sanctuary. Only Henry House has video (coax) cabling. Gratton's system was installed for the purpose of future telecommunication uses. It includes both the main building and Henry House (see the file henry...). There are about a hundred circuits in the main building. Only several were in use in 1996. Robert Gratton worked on it and installed both audio and video wiring while Henry House was being built in 1964. He wrote/drew an 8 p. document (including wiring diagrams) bound in a Manila folder (or in a ringed notebook) which has been lost. Then Bal Pickering became in charge of it. Gratton left the church in the 1960's but is still living in Pasadena. The new system in plastic conduit is only for the sanctuary. It runs between the box near the SE corner sanctuary to the Pulpit and then on to the closet at the N end of the narrow hallway by the W. exterior wall (behind the Chancel). It is currently used for the sanctuary audio system and was installed in part by Jim Stiver. Since it's conduit, it's easy to install new cables in it. The following paragraphs describes the old system which is not in conduit. In the main building, a main "trunk" of 5@ large cables runs the under the floor of Throop Hall from under the public telephone room to the stage basement. A J-box (Junction box) with terminal screws is at each end of this run. From each end of this main trunk are 2 branch runs: one from under the public telephone room to the Projection Booth and another from the stage basement to the sanctuary pulpit. Henry House has several wooden J-Boxes mounted on the walls inside the building. There are two underground runs (2 different conduits) between Henry House and the main building. Historical note: As of 1996 four circuits were in use between the Projection Booth and the Stage: 2 pair of wires for the microphone jacks (XLR balanced, low impedance mic) in front of the Stage and 2 pair for the overhead loudspeakers in Throop Hall. In the late 1990's these were not used anymore and the 2 loudspeakers were removed. As of 2001, only the following circuits of the old system (non conduit) were use in use: Lamp cord used for PA speakers in the sanctuary runs under the sanctuary floor (some unused spare runs). A cable from Henry House provides telephone service (via 5 twisted pair) to the public telephone room. In the future, spare circuits could be used for PA, intercoms, telephones, burglar alarms, computer networks, etc. The wiring consists of multiconductor cables (with color-coded twisted pair, some shielded), some lamp cord (for loudspeakers), and several interconnection junction boxes containing screw terminals. There is no fiber optic cable (yet) but there is coax cable in Henry House. Most of this wiring is in the crawl space under the first floor, inside the walls of Henry House and in the basements. See "Access" document re how to get into the crawl space. The "boxes" (some without covers) containing terminal strips are variously called terminal panels, junction boxes (= J. Boxes) etc. In the main building they are located in: SE corner of projection booth, in the crawl space off the electric basement (under the public telephone room), in the crawl space under the sanctuary (under the N aisle where it goes under the balcony), on S. wall of SE room of the stage basement, on W. side of the stage, several places in Henry House. SANCTUARY (old system): From under the pulpit 4 pairs of brown lamp cords feed the 4 speakers. A multiconductor cable end is loose in the crawl space here. This cable runs from here to a covered junction box located in the crawl space under the rear column of the N. aisle. Need a wrench or screw driver to remove the cover. It is about 14 feet from the N. Wall. Many other cables lead out of this box: 2 brown lamp cords (speaker cables) go directly W. toward the chancel. 3 more such cords and 3 round gray cables go N. and then W. toward the chancel. Two multiconductor cables go to the stage basement terminal panel. On the S. side, a lamp cord which goes to a phone jack for the hard-of-hearing has a cut end in the crawl space (goes nowhere). THROOP HALL: Under Throop Hall between the two basements run 5@ multi-conductor cables. There are 1@ 25-pair, 2@ 13-pair, and 2@ 4-pair. The 13-pair and 25-pair are of telephone size wire gauge (thin) with each pair unshielded. The 4-pair are of speaker size gauge (thick) with each pair shielded. The overall (exterior) size of the 4-pair cable is smaller than the 13-pair cable even though the 4-pair conductors are larger. The 25-pair cable connects the 2nd floor of Henry House to the Public Telephone room of Throop Hall, bypassing both junction boxes in the Stage Basement and in the Electric basement. Between Henry House and Throop Church it runs in a conduit which is clearly visible on the outside of both buildings. The other 4 cables run between a terminal panel (= J. box) in the "patio" room of the stage basement and a similar J. box off of the Electric basement. Although only 2 of these cables are connected up to terminals at both J. boxes. STAGE BASEMENT J. BOX: Sanct. = Sanctuary Terminal Panel EB = Electric Basement Terminal Panel (in crawl space) CODE CABLE FROM TERMS. USE 2B 13-pair EB top spare (cable not connected at EB) 1B 13-pair EB bottom Hall speakers (2-pair), 2 pair to Sanct. via lg. cable 1A 4-pair EB centerL.Stage mics (2-pair), 1 pair to Sanct. via small cable 2A 4-pair EB centerR.spare (cable not connected at EB) 3A 4-pair Sanct. few Only 1 pair connect to 1A. See above. 3B 13-pair Sanct. few Only 2 pair connect to 1B. See above. Note that the "code" is my "invention" and is not marked on the cable. Most pairs of 3A and 3B are not connected to any terminals while the other cable wires are fully connected to terminal screws. Historical Note: Problems with old system: (The Throop Hall speakers were removed in the late 1990's.) Was the Throop Hall speaker feed heavy enough? It was perhaps 22 gauge. It's was a 70 v. line system but ... Speakers seemed to sound better when connected directly to an amplifier setting on the stage (via alligator clips.). The 70v matching transformers inside the speakers also decreased the low frequency fidelity. ELECTRIC BASEMENT J. BOX: ProjB = Projection Booth StageB = Stage Basement Term Panel An open terminal panel is about 6 ft. to the left as you crawl into the crawl space behind the small high door in the electric basement. All connections are of the same color codes (e.g. red connects to red). Except for a few pairs which don't feed thru, this panel is nothing more than a splice which connects cables 1B to 1b and 1A to 1a on their way from the Stage Basement to the Projection Booth. The Henry House to Telephone Room 25-pair cable goes right past this box. Much dust is on these wires due to no cover. CODE CABLE FROM TERMS. USE 1B 13-pair StageB left feed to cable 1b to Projection Booth Hall speakers (2-pair), blu-blk and blk-white pairs don't feed thru. 1A 4-pair StageB right feed to cable 1a to Projection Booth Stage mikes (2-pair), white/red & white/black wires don't feed thru. 2A 4-pair StageB none spare 2B 13-pair StageB none spare 1b 13-pair ProjB left connects to 1B see above 1a 4-pair ProjB right connects to 1A see above SUMMARY of MULTI-PAIR CABLES: There are 4 runs of "big-little" cable pairs ( = one 13-pair cable and one-4 pair cable). They are not numbered 1 to 4 however. Theses runs are: 1 & 2. StageB J-box to Electric Basement J. Box (2 runs => 4 cables) 1.(a&b) Electric Basement J-box to Projection Booth. 3. Sanctuary J-box to StageB J-box (#3). Runs 1 and 1(a or b) are almost like one run between the StageB and the Projection Booth due to the way the cables are mostly connected to each other via the terminals at the Electric Basement J. Box. The standard number of pairs for telephone cable are: 1, 2, 3, 4, 6, 12, 18, 25, 50, 75, 100, 150, 200, 250, 300, 400, ..., 2700. Are some of ours really 13-pair ? There are also 2 single runs of many-pair cables: 1. 25-pair Henry House to Public Telephone Room (of Throop Hall). A coil is by the Electric Basement J. Box => possible to pull it further. 2. Sanctuary J-Box to Pulpit (Loose end in crawl space. 13? pair.) STAGE: A J-Box is on the W. wall of the stage which connects to Henry House via an underground conduit. SUPPLIERS: Graybar (Los Angeles) carries a large selection of multiconductor cable. Marvac-Dow (Pasadena) has some multiconductor cables.