A few inches trimmed won't have any noticable effect on the timing. The precision of the adjustment is not that
Gord pretty well covered the details of practice in actually making the splice or connection. Where EMI is concerned, it's noise
from external sources that you want to keep out of the radar signals. You definitely want to keep moisture out as it will migrate up the cable and affect signal quality. If you look inside many scanner units, especially older models, cable dress isn't much of an issue. (The old Pathfinders had a long strip of push-on
connectors inside, and plenty of loop-length to make assembly easy.) New units I've been into are much neater, but newer circuitry is actually more
immune to interference
. Ferrites are placed on the cable in the scanner to prevent stray RF from following the cable and possibly interfering with other equipment
. Most of the wires carry analog power and control voltages, modern recreational radars are designed to keep sensitive circuits together at one end or the other. As Gord said, you want to keep the circuit wires grouped and shielded as they are in the cable, and minimize extra length in the wires, especially shields. You want to keep separate shields separate, even though they are connected together at one or both ends. Usually there are two groups, separately shielded to prevent signals bleeding from higher power circuits in one group to low-level signal circuits in the other.
Splicing a radar cable does require a fairly high level of proficiency in soldering and wiring
, and I realize I have spoken of it as though it was a little simpler than it is in practice. It's not something to go at lightly when you are responsible for a customer's several thousand $ equipment
, nor your own. A connector set, e.g., AMP CPC Series, is good for mast
installations that may have to be disconnected in the future, but these require as much or more skill to install properly, as you have to work with very short and precise wire lengths and very close spacing. You can end up with a ball of spaghetti that won't fit into the connector shell, and excess bare wire at the terminations can short to other conductors when assembled, possibly damaging your equipment.
I ought to have included words of caution from the start - it's not as easy in practice as it is on the screen
. You must be fully proficient in the required skills. An inline splice requires technique for overlapping and soldering shields without damaging the insulation
of the conductors below. Conductor splices must be staggered, and each length conforming to the overall splice length. The conductors must be twisted together neat, tight and close, and the length still conforming to the overall splice before soldering each. Proper cutters and cutting technique is required to insure that a strand of wire cannot poke into another conductor. One of these splices takes me a couple of hours or more to do - it may be cheaper to buy the cable - when I have to do it, saving $ on the cable is not the reason.
All interconnection cables for marine electronics
are high priced. The manufacturers nail us on these to help make up for competitive pricing of the units. It is a rip-off, but since they all do it, we're stuck. Radar cables are that much more expensive because they are custom made for the electronics
manufacturers in volumes that are nothing in the wire & cable industry.
I did once take a series of photos of making a radar cable splice, & do promise to annotate and post them sometime soon.