Fabricating Coax Cables for Experimental Aircraft
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- เผยแพร่เมื่อ 9 ก.พ. 2025
- Radios and navigation equipment used in Experimental aircraft require custom coax cables for connection to their antennas. This video Tip discusses the best coax cable to use in an aircraft as well as demonstrating how to install the BNC connectors to the cable ends. The ability for the builder to fashion their own cables is a skill that will provide benefits for years to come.
Below are links referenced in the video:
Steinair RG400 BNC installation video:
• 010: BNC COAX CONNECTO...
Blade adjustment video for Stripper Coax tool:
• Insulation Stripper HT...
Steinair Crimper SKU: SAT-001
www.steinair.c...
Previous Tip archive:
homebuilthelp.c...
Good job John. I just learned this by the seat of my pants a few months ago. Couple of suggestions....1) the hole in the small inner gold pin is a witness hole and the inner cable length is correct when you can see it thru the hole; 2) the same pin is actually held in place in the main body by a detent, and its important that it engages in that detent or the pin wont be at its maximum stick out and you wont get a connection when you hook your cables up; 3) buy at least two extra BNC connectors and expect them to be sacrificial "practice" because at least the first time you do this, you'll probably screw it up...so also leave a bit of extra cable in your run to accommodate that; 4) GPS TNC connectors, like on Garmin antennas look quite a bit different from the ubiquitous BNC but are made the same so dont freak out about that. Finally, +1 for Stein Bruke and his gang. Def watch his videos and patronize his business.
Good comments Mani. Thanks
you shouldnt be able to see thru the witness hole, if you can that indicates the core is too short
Good comment and I was about to say some of the same things: inspection hole and locking of the pin into the connector body. I will add one more thing and that is to check for continuity before you crimp the ferrule. If you have continuity between pin and body, that means you have a stray piece of braid shorting to the center conductor and no use wasting a ferrule as you need to cut off the connector and try again. And I do a final continuity check after the crimp to ensure that this is no electrical connection between the pin and connector body.
Thank you! I am a ham radio operator. I went out to the field with my radio, only to find out that, since yesterday's operation, the coax has failed a few inches below the connection. Guess the jacket got tired of the cold weather and being outdoors. Your video has helped me a lot.
I'm a new builder, and these videos are AWESOME. Could not be explained better. THANK YOU!
JON,
THANK YOU FOR CLARIFYING THE PARTICULARS WITH COAXIAL CABLE SELECTION AND APPLICATION. I WAS VERY IGNORANT ON THE SUBJECT UNTIL YOU POSTED THIS FANTASTIC VIDEO. PLEASE KEEP UP THE GOOD WORK. GOD BLESS!
To show a close up view of the detail work you're performing, you can place your hand behind the the target shot and the camera will focus on the close up view. Love your instructional and demonstrative videos!!!
Firstly, thanks for providing these videos. They're a wonderful bite sized learning resource and much appreciated. Point of correction though: you mention that Teflon will not turn into harmful gasses on combustion. In reality, Teflon is a trade name for PTFE (poly-tetra-fluoro-ethylene). While it has a higher melting point than polypropylene used on the RG58 family, its thermal breakdown products will include halogenated compounds which are highly toxic. Although this will probably be mitigated by the ventilated environment likely in an aircraft fire. Once again, thanks for the informative and entertaining videos
Kav Ghanouni Another hazard with teflon use is that if you melt it and a drop lands on your skin , it will keep on melting and dissolving flesh as it eats through your finger , hand , etc.............bad nasty stuff if melted..
WHICH TYPE DO YOU PREFER SIR. THE RG-58 OR RG-400?
Im planning to build a plane and have plugged in the mission information with your videos. Very helpful
missing information*
Admittedly, I never knew how those RG connectors terminated and ended up with cables pulling out. Luckily it was not for aircraft, thank you for that!
Very informative. Please consider doing another on TNC & 90 degree BNC connectors. Thanks. Cm
The most important part is the silver plated double screen - this keeps RF inside the cable so it doesn't cause havoc with sensitive instrumentation, and also provides a good barrier in reverse to keep whiney nasty noises out of your sensitive receiver. The silver plating is important, because as it ages and oxidises it forms silver oxide - which is an excellent conductor!! Oxides of copper, conversely, are a particularly bad thing to be developing inside your aircraft cabling. Consider covering the ends with glue-filled heatshrink, and also a sheath of it can be added elsewhere along the cable for strain relief or abrasion resistance.
Both silver and copper oxides are pretty good conductors. Unfortunately, copper oxide will harden and embrittle the strands, making the shield very fragile. This is also true of silver, but to a much lesser degree. Marine heat-shrink at the joints is not a bad idea, especially with those sub-market connectors in the video that don't feature any seals.
Nice Job.....another source of information which is very good info is the EAA.Videos for homebuilt hints.....under crimping. I recommend using the EAA Videos as well.
In order to determine the amount to cut for each step of the cable, just download the datasheet for the specific BNC connector that you have. They are all available if you search for the part number.
Thank you for this video 🙂
Informative. My Sargent been hounding on me if I know how to build one. We mostly solder our pins on though.
For whatever reason, military aviation LOVES soldering, despite it actually being less reliable. I can't say I miss it. Good luck to you, man.
@@SwervingLemon Jeez, flashback to my USAF high-reliability soldering course in 1989. That's where I learned what properly wicked solder looks like.
The little hole in the side of the brass center connector is for wicking solder in..........makes a better conductor for your radio output and keeps the connection from developing corrosion...........any electrical resistance will diminish your radio ouput...........i solder all connections in all wiring harnesses i make...........wire will not pull out of terminal ends , corrosion will not build up , and it is guaranteed to perform............i use uninsulated terminals soldered on and heat shrink to insulate the end............if you use clear heat shrink , you can put an idenitifer tag under the heat shrink for circuit ID that is permanent and readable..
Thanks. Excellent suggestions.
Incorrect. The little hole is an inspection window and is designed to allow inspection of the proper wire insertion depth prior to crimping. These types of terminals should not be soldered unless the manufacturer specifies that and none do that I am aware of. Soldering is actually harmful in auto and aerospace applications subject to vibration as the solder wicks down the wire, stiffens it and leads to early failure under flexing.
The strippers come with a straight blade and a blade with the notch for cutting down to the center conductor. Since you did not cut down to the center conductor with the stripper, but only removed jacket and shield braid, did you replace the notched blade with a second straight blade? Or does the notched blade work OK to cut the shield braide, but leave the dielectric intact?
Nicely done.
Can you share what letters you have the blades set to (on the inside of the tool) in order to get the right length when stripping?
Doing it yourself will probably give a better outcome than contracted results (SteinAir does outstanding work --- but Aircraft Spruce, not so much --- I've gotten more than one cable from them where the BNC connector fell off from the RG400. Don't buy pre-made cables from Spruce)
Great video!
i do these for a living on cell sites and first responder systems. I just have one question no testing?
I’ll have to get a set of dyes for my crimper. Looks Easier than soldering.
About the loss of the RG-400 vs RG-58: at what frequencies and cable length did you measure this?
It's a 50-ohm cable with a fairly accessible spec sheet. You're delving down a pedantic rabbit hole, there.
Does the Budweiser help the cable making process? I’d think so with how many terminations you need to make. Great video!
Ha, Ha, I had to watch it again, I thought it was a can of Coke the first time!
Saw that too. Loved it!
Would you add Mix 31 ferrite beads heat-shrinked onto the coax for RFI suppression? KC9WDH
"...and this will take some force"... audio goes dead as curse words ensue.
Yup. RG400 is slightly wider than RG58. Make sure connectors (and their collars) are designated for RG400. RG58 collars (and some Chinese made RG400) wont fit over the RG400, thus the curse words and "some force" getting that collar over the wire.. Ask me how I know.
I find less force is required if the braid is flared out a little with your fingernail before sliding on the connector. This causes it is slip under the braid rather than pushing it back and bunching up as in the video. Then just pull it back toward the connector a little before sliding on the ferrule and it is much easier.