AIR-FORCE ONE
DIY interconnect cable by Guus Das

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Ingredients   A recipe is as good as its ingredients. Main ingredient in our project is the hollow braided conductor. I used the braided shielding of a professional grade miniature coax-cable. It was silver plated high purity OFC. Next important ingredient is the Teflon sleeve through which the conductor is led. I was not able at the time to obtain such material so I used the outer sleeve of a one-size bigger coax cable. This sleeve was from the material FEP, closely related to Teflon with respect to dielectric properties. So here is room for improvement in a future project. However, the amount of contact between the conductor and the sleeve is so little that this probably has no audible effect.   Mini-coax cable. Outside diameter ~1mm. Shielding wires silver-plated OFC-copper. Teflon sleeve, or Teflon cable (coax) with an inside diameter 1.5 to 2 times the size of the mini-coax cable. Typically 2mm coax-cable. Shielded jacket with an outside diameter between 8 and 9mm, see chapter 9. o High-end grade RCA connectors with cable insertion opening matching above cable (8 - 9 mm). Shrink sleeve for 4mm and for 9mm. High-end grade Silver-Tin solder. Faston connectors, 1 male and 1 female per cable. Drill a 3mm hole in the male connectors. Sleeve Cutter, see description below. Ferrule (4x) as used in pneumatic systems to clamp soft tubing. To the right, the ferrule I used.   Preparing the sleeve   If a Teflon sleeve can't be obtained, next best thing is to peel-off the sleeve of a high quality (coax) cable. In this case sleeve material was FEP. Pure Teflon is difficult to peel off without deforming.   Cut off a piece of the 2mm (coax)-cable (~20mm longer than needed). Cut off ~20mm of the sleeve, to get a good grip on the inner cable-part. Remove the sleeve by pulling it several times between your thumb and finger, holding the inner parts firmly in the other hand. This may need some practice. The picture above shows a 2mm coax-cable. In the middle the removed inner cable-part that is discarded. At the left the sleeve we are going to use. The inside diameter of the Teflon/FEP sleeve must be ~ 1.5 times larger than the outside diameter of the mini-coax shield. Bottom picture shows the 1mm coax-cable with part of it's sleeve removed next to the previously prepared bigger sleeve     next page: