Mobile Install 3.0… physical attachment of wires to things

As I said, there’s going to be more to come on this. Shortly after publishing my last entry on this overall topic, I realized that this was something I wanted to discuss at some length.

On previous installs, I was a FIRM believer in soldering ALL of my connections. I had the belief that the joints would be better for long term strength… why? well, in the past, I had crimped, and had connectors come off easily from a small tug. In reality, I did a crappy job in crimping the connections – there’s no better way to put it. I used the wrong tools. I either used a cheap dollar store crimper or just tried whatever pliers I had.

I knew – and ignored – the fact that aircraft installations are ALL crimped. Generally speaking, they use will maintained, calibrated crimping tools. These tools, connectors, and crimps, are generally a 4-sided crimp. Additionally, the terminals are specifically sized for the wire – so they don’t try and crimp a 20 gauge wire into a 12 gauge terminal (and neither should we!).

Now… why don’t the aircraft companies solder? well, several reasons. Economy is one – it’s faster, safer, and easier to crimp. Security is the second – with the thermal and pressure changes an aircraft will undergo, solder joints would be more prone to cracking and failing than the crimp would be. While it would be possible to solder some and crimp others, it’s better to use the same process for ALL of the connections so there are not mistakes regarding which process is used for which harnesses.

For this install, I generally crimped all of my terminals – but I didn’t use a cheap dollar-store crimper. In this case, I either used a proper Eclipse crimp tool, which is a multi-crimp tool, intended to crimp tighter around the wire than the insulation, or I used a Klein tool, which crimps a “U” shape on the wire.

I did use a lot of powerpole connectors for interconnections – and I even crimped those. The toughest connections to crimp were the accessory wire, where I sued a 20 gauge wire. Since anderson doesn’t have a specific terminal for that gauge wire, I stripped a couple inches of the wire, and rolled it over to provide more wire for the terminal to crimp on to.


RF connectors, on the other hand, are another beast altogether.

That being said for non microwave (<1 GHz) applications, and application under 100W, crimp-on BNC, Mini-UHF, or even PL-259 connectors are just fine…. or even type N if you’re crazy like I am. See my post on connector selection for further discussion on that topic.

For high power and high frequency applications, I far prefer soldered connections, whether it’s SMA, BNC, or PL-259 (which I don’t use often).

This is one area where the pros do it, and it’s just fine. They suffer, possibly, even more than amateurs, from loss on RF lines if it’s not done right – people’s lives depend on those Motorola Radios – so it can’t be half-assed.

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