Building Ronja Signal Cabling2

What we are going to build

We are going to:

Build one 1.5 meter long power exchange cable (W2-PWR)
Build one 0.6 meter long RSSI cable (W5-RSSI)
Equip the signal cables(s) (W1, W2, W5) with connectors (W4 and DE9).
Attach a W3-PROT lightning protection cable attached to W2-PWR.

Purpose of the cables

Power exchange cable (W2-PWR) allows both optical heads to share electrical power. The optical heads take electrical power from shields of the signal cable(s). Shield of RX signal cable (W1-RX) carries +12V and the shield of the other signal cable (W1-TX) carries 0V (Ground, GND).

Some connectors within Ronja 10M Tetrapolis/Inferno system are made of pieces of thick copper wire (W4), some are DE9.

W3-PROT lightning protection cable protects your home electric installation from a fire hazard if lightning strikes directly into the shield of signal cables (W1) laid on the roof. TV antenna and TV set are protected the same way.

Cutting

Cut the following wires:

Designation	Number of pieces	Length	Thickness (crosssection area in mm^2)	Solid Wire/Stranded	Insulated	Shielded	Number of (inner) conductors
W1-TX	1	Distance from PC to intended optical head mounting site		Any	Yes	Yes	1
W1-RX	1	Distance from PC to intended optical head mounting site		Any	Yes	Yes	1
W2-PWR	1	1.5m		Any	Yes	Yes	1
W3-PROT	1	1m	1	Stranded	Yes	No	1
W4-STUB	12	29mm	4	Solid Wire	Any	No	1
W5-RSSI	1	0.6m		Any	Yes	Yes	1

Postscript / PDF / EPS / BIG png / SVG (Inkscape)

Stripping

The W1 and W2 will be stripped asymmetrically. Let's call the ends short and long end.

Strip all the wires:

Wire insulation ID	Length
(W1 long end, W2 long end, W5) outer insulation	29mm
(W1 long end, W2 long end, W5) inner insulation	4mm
(W1 short end, W2 short end) outer insulation	10mm
(W1 short end, W2 short end) inner insulation	3mm
W3-PROT	10mm
W4	Remove all insulation

When stripping the outer insulation, take care not to cut the thin wires of the shields.

Strip 10mm off W2-PWR outer insulation in the middle, so that the shield becomes accessible.

Covering with solder

Twist all visible stranded copper up. Cover the ends of the conductors with solder:

Wire ID	Length of solder coverage
W1, W2, W5	4mm
W3-PROT	10mm
W4	4mm in the middle of the stub

Cover the stripped place in the middle of W2-PWR with solder too. Solder up one end of W3-PROT to this place.

		PostScript	PostScript + Gzip	PDF
Color	Dark	cabling2_01.ps	cabling2_01.ps.gz	cabling2_01.pdf
	Light	cabling2_00.ps	cabling2_00.ps.gz	cabling2_00.pdf
	Small	cabling2_02.ps	cabling2_02.ps.gz	cabling2_02.pdf
B/W	Dark	cabling2_11.ps	cabling2_11.ps.gz	cabling2_11.pdf
	Light	cabling2_10.ps	cabling2_10.ps.gz	cabling2_10.pdf
	Small	cabling2_12.ps	cabling2_12.ps.gz	cabling2_12.pdf

cabling2.sch (gschem)

Soldering the DE9 connectors

Solder one or two DE9 connectors on the W1- cables, depending on whether two cables fit into one enclosure or not. Use the thin (0.7mm^2) hard copper wire to interconnect the pins and the shell. Make sure the connection to the shell will not prevent cover installation.

Postscript / PDF / EPS / BIG png / SVG (Inkscape)

Ends

Solder eyelet on the single end of W3-PROT. Solder stubs (W4) on all free ends of W1, W2, and W5 according to the drawing.

Conductor designator	Colour	Function
W1-RX shield	Red	+12V
W1-RX inner	Blue	Signal
W1-TX shield	Black	0V (GND)
W1-TX inner	Blue	Signal
W2-PWR shield	Black	0V (GND)
W2-PWR inner	Red	+12V
W3-PROT	Black	Earth protection
W5-RSSI shield	Black	0V (GND)
W5-RSSI inner	Blue	RSSI voltage

Insulation

Wrap up (insulate) the soldered joints with coloured duct tape according to the table. Use enough tape to reinforce the ends of the cable mechanically too (to prevent it from breaking off during repeated bending).