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Belden 89259 DIY Hi-Fi RCA Interconnect Cables

Simon Au   Canadian Flag   auDIYo.com

Belden 89259 DIY RCA Interconnect Cables

Step-by-step instructions are provided to construct the popular line-level interconnect cable design by Jon Risch. Full technical details of the cable design are noted on Jon's site. This is an unbalanced RCA interconnect cable design using the low capacitance Belden 89259 coaxial cable. Belden 89259 is a RG-59/U plenum rated coax cable with a stranded (7x30) center conductor and bare copper braid shield. Insulating materials are FEP (Teflon) dielectric and outer jacket. The heavy copper shield, low capacitance and premium insulating materials make this a super cable for a wide range of DIY audio cable projects, it works great for speaker cable, interconnect and digital cables. There is also a speaker cable project, the Cross-Connected Belden 89259 DIY Hi-Fi Speaker Cables which uses the same coaxial cable.


Required Parts and Tools

The following parts will be required to complete a stereo pair of the interconnect RCA cables. All of the noted parts are available from auDIYo.com.

Table 1: Required Parts for Belden 89259 DIY RCA Interconnect Cables

Description Quantity for one pair
Belden 89259 Coaxial Cable
Male RCA Plugs
 1/4" TechFlex (expandable sleeving)nbsp;
1/2" Heat Shrink
Solder
 2 (equal finished lengths)
 4
 2 (1 inch shorter than coax cable length) 
 4 (2.5 inches each)
 As required.

Required Parts for Belden 89259 RCA Interconnect Cables

Photograph 1: Required Parts for Belden 89259 RCA Interconnect Cables

Shown in the photo below are the tools that will be required to construct the Belden 89259 RCA Interconnect Cables.

Required tools for Belden 89259 RCA Cables

Photograph 2: Required tools for the Belden 89259 RCA Cable Project

Photograph 3 below shows some optional tools that were found to be helpful with our cable assembly method.

Optional tools for Belden 89259 RCA Cables

Photograph 3: Optional tools for Belden 89259 RCA Cables


Belden 89259 RCA Cable Construction

A section of the Belden 89259 coaxial cable which identifies the cable jacket, shield, insulator and conductor is shown below in Photograph 4.

Belden 89259 Coaxial Cable

Photograph 4: Belden 89259 Coaxial Cable

The following steps outline the preparation of the Belden 89259 cable:

1. Using a stripper/cutter, side cutters or a utility knife, cut 2 equal lengths of Belden 89259 cable.
2. Measure the approximate stripping length of cable against the barrel of the RCA plug (Fig. 1).
3. Using a sharp utility knife, lightly cut the cable jacket along the measured stripping length (Fig. 2).

Note: Our coaxial stripper tended to strip away some of the shield so we used a sharp utility knife.

4. Pull back the cut jacket and trim away the excess as shown in Fig. 3.

Belden 89259 Unbalanced RCA Cable Construction

5. Comb back the copper shield and tightly twist together as shown in Fig. 4.

Belden 89259 Unbalanced RCA Cable Construction

6. Strip away approximately 3/16" (5 mm) of insulation with a coaxial stripper (Fig. 5).

Note: When using a coaxial stripper to remove the insulation, turn one revolution only. Any more than one revolution may cut into the conductor. You can practice using the coaxial stripper on a test piece of coax cable before using it on the Belden 89259 cable. A stripper/cutter may be used instead of a coaxial stripper.

Belden 89259 Unbalanced RCA Cable Construction

The instruction below have been put together for a Cardas Silver RCA plug. Of course you can use your favorite style of plug, but depending on the RCA plug that you choose, the specific details will change slightly, but the general idea is the same. Photograph 5 shows an RCA plug and identifies the cover, barrel, bridge, tit and signal pin.

Male RCA Plug

Photograph 5: Male RCA Plug

7. Bend the bridge so it will accept the twisted shield by placing a screw driver on mid-point of Bridge (Fig. 6).
8. While holding the screw driver in place, carefully tap the screw driver to bend Bridge (Fig. 7).

Note: Do not over bend the bridge. Doing so will cause interference with the coax insulation. The center of the bridge may crack while bending. This is normal as a result of the brittle material.

Belden 89259 Unbalanced RCA Cable Construction

9. Bend the bridge until the gap is just large enough to fit the twisted shield (Fig. 8).

Belden 89259 Unbalanced RCA Cable Construction

10. Preheat and apply solder sparingly to both the conductor and tit (Fig. 9).
11. Solder the twisted shield to the RCA bridge using the same method described in step 10.

Note: Before connecting the remaining RCA plug on the other end, you must first insert the TechFlex expandable sleeving and heatshrink wrappings.

Belden 89259 Unbalanced RCA Cable Construction

12. Slide the TechFlex expandable sleeving and the two 1/2" diameter x 2.5" long heatshrink wrappings over the cable from the non-terminated end. (Fig. 10).
13. Repeat soldering steps 10 and 11 to terminate the remaining cable end.
14. Using a the continuity or resistance measurement feature on a multimeter, test for cable shorts by placing one lead on the RCA signal pin at one end and the other lead on the RCA barrel or cover (Fig. 11).

Note: An infinite reading or no value indicates that the cable connection is good and not shorted.

Belden 89259 Unbalanced RCA Cable Construction

15. Screw on the RCA covers an place heatshrink about 1/2" over the RCA plug and shrink the entire length.

The finished cable following the above instructions is shown below.

DIY Belden 89259 RCA Cable

Photograph 6: DIY Belden 89259 RCA Cable


Belden 89259 DIY RCA Interconnect Cable Photographs

Photographs of other completed Belden 89259 line-level RCA Interconnect Cables to give you some finishing ideas. If you have finished this cable design, send us your photos and we will add them to the page.

Belden 89259 RCA Interconnect Cable

Photograph 7: DIY Belden 89259 RCA Cable - by Paul from Kent, UK

The Belden 89259 coaxial cable can also be used for DIY speaker cables. See the Cross-Connected Belden 89259 DIY Hi-Fi Speaker Cables project for speaker cable instructions.