The Cabling Problem

1. The Cabling Problem • Our shielded cables are too rigid, so we need to find a more flexible alternative to connect our detectors. • Our solution is to use flexible coaxial cables • We also need the cables to work with a 34-pin connector. • This creates a new problem, how to attach the connectors to coaxial cables. There is presently not a convenient / easy solution for this.

2. The Cables There are several manufacturers of cables that we looked at • Temp-Flex • Manufactures flexible coaxial ribbon cables • Cooner Wire • Manufactures ultra-flexible coaxial cables, but not in a ribbonized format

3. Temp-Flex • Produces Coaxial Ribbon Cables • More flexible than our existing cables, though not as flexible as the Cooner Wire • Can be entirely bonded or intermittently bonded (the cables are separated periodically for increased flexibility) • The separation could cause problems if we were wanting to make cables of differing lengths; the bonded cable should be flexible enough for our purposes while being better for cable-making

4. Cooner Wire • Produces ultra-flexible coaxial cables • Con: Are not joined, so more prone to tangle • Pro: more flexible than the temp-flex cable (since they aren't joined)

5. Pricing • Temp-Flex • For 17-signal coaxial ribbon cable, $14.00/ft • Required to buy at least 100 feet, we don't need that much, so would use two 17-signal ribbon cables per 34 pin detector • Cooner Wire • Do not currently have the same cooner wire we have used in the past, in stock. Sending a sample of a slightly different one for us to look at, and will give pricing information after we have seen it. • As a price reference, the 75-ohm they have in stock is $6.47 for 100 feet.

6. JoySignal's Prices For pre-assembled coaxial ribbon cable with connectors, there is a sunk cost of $2500, plus a per-piece cost 50 units at $274.69 each = $13734.50+$2500 = $16234.50 • This is approx $325 per cable 100 units at $258.53 each = $25853+$2500 = $28353.00 • This is approx $285 per cable

7. Qualities of the Cable • Temp-Flex Ribbonized • Signal insulated with 8 mils of FEP • Fluorinated ethylene propylene • Jacket insulated with 9 mils of THV • Tetrafluoroethylene hexafluoropropylene vinylidene fluoride

8. The Process Once we get the cables, we have to connect them to electronics Joy Signal Electronics makes custom cable terminators (connectors). I spoke with a representative (Chris Shmatovich) at length about their process. They solder the cable to a small circuitboard which they use to connect the signals to a connector The next slide has several pictures of cables and circuitboards in various stages of the construction of one of these terminations

10. The Circuit Board In this, we see an example of a circuit board used for a connector; the microcoaxial cable is soldered onto the circuit board; the shielding is attached to the solid strip, and each signal will go to a pin of the connector

11. The Circuit Board, 2 Here we see cabling soldered onto the circuit board from the previous slide

12. The Circuit Board, 3 For our purposes, the circuit boards will be similar to these, and fairly small (probably a few square inches). If we use two-layer boards, 60 square inches cost $33 per sheet of boards, plus a $50 surcharge for multi-board sheets. If we were to use four-layer boards, we would have 30 sq inches to work with for $66 per sheet + $50 surcharge. It shouldn't be particularly difficult to assemble these, though probably a bit time consuming; the cables (if ribbonized) will need to be separated and then stripped in two tiers—the shielding will need to be exposed, then pulled back, exposing the signal line. The insulation over the signal line will then need to be stripped as well

13. Stripped Cable This is a piece of the ribbonized cable I separated, cut off and then stripped The right side has shielding peeled back, the left does not. (I couldn't get an in-focus picture with my camera, unfortunately)

14. If We Made the Cable Using Temp-Flex cables, we would pay $1400 for the cables themselves (buying 100 feet of the 17-signal cable) The 17-signal cable is just under an inch wide, so a circuit board would probably be on the order of a few square inches. We could fit a lot of these on one sheet, so the cost per cable of the circuit boards becomes very small. (If we assumed fitting 10 4-layer boards per sheet, we would be paying under $10 per cable for circuit boards)

15. My Opinions I feel that the temp-flex cables make considerably more sense from a practicality standpoint, and likely a price standpoint; given the price-point of the 75-ohm Cooner wire and the fact that that's just for 100 feet of one strand, we would need to order 1700 feet to have an equivalent amount to the temp-flex. This would decrease the price per foot, but probably not cheaper than the Temp-Flex. The fact that the temp-flex is already joined is also a great boon, as otherwise we would probably need to wire-tie the cooner wire together at several points to prevent it from getting tangled. Storage of the cooner wire cables would also be very prone to entanglement.