TNC crimping instructions

foka4 · #1 07-20-2010, 01:40 PM

Does anyone have a detailed cheat sheet on installing the Amphenol 225555-6 TNC connector on RG-400 coax cable with homebuilder's hand tools?

I'm wiring the antenna for my Garmin 430W, and I don't want to screw up this $30 connector.

Thanks,

Matthew

foka4 · #2 07-20-2010, 02:39 PM

I guess this is a good place to start:

http://www.tycoelectronics.com/comme...8-2299-1_O.pdf

Neal@F14 · #3 07-20-2010, 03:02 PM

$30 for a normal crimp-on TNC male connector? Ouch!

Mouser has this one for a buck and a half:

http://www.mouser.com/Search/Product...6FZg%3d%3d

It says it's for RG-58 but I just used one just like it on RG-400 last week and the crimp sleeve was a tad tight since the shielding on RG-400 is a bit thicker and more robust than cheap-o RG-58, but it worked just fine. It crimps on exactly the same as a BNC connector. The cable I made was for a Becker transponder, with one TNC and one BNC and about 5 feet of RG-400.

Stein Air sells a relatively cheap coax crimper that works great for about $42 for the crimper and coax/BNC die. I think they also sell a less expensive TNC crimp-on connector too, but it's not listed on their website, you'd have to call them for it.

Jim Percy · #4 07-20-2010, 03:50 PM

Not sure what you mean by "homebuilder's hand tools", I'm assuming you have a suitable crimper. Here are some instructions for a specific tool that should be somewhat universal (with the above assumption).

http://www.aeroelectric.com/articles/bnccrimp.pdf

Garage Guy · #5 07-20-2010, 05:02 PM

Quote:

Originally Posted by Neal@F14

$30 for a normal crimp-on TNC male connector? Ouch!

Well, the Tyco/AMP 5225555-6 is a weatherproof mil-spec connector... not exactly 'normal'.

Another really nice male TNC connector for RG-400 is the Amphenol 031-4452. Mil-spec, teflon insulator, silver plated. About $10 each, so not real cheap either.

But if you're going with RG-400, these silver plated mil-spec Amphenol connectors just go so well with the silver plated braid and center conductor on the cable. For a panel mount GPS cable, install a 031-4452 TNC on one end and a 031-4427 BNC on the other, and it is a thing of beauty

.

--Paul

foka4 · #6 07-21-2010, 10:13 AM

I guess the 225555-6 is overkill, but it's what Stein provided with my 430W, and in my experience, they usually have a reason for doing things one way vs. another.

Dimensionally, the center pin and collar of the 225555-6 are a little different than the usual BNC components, so I wasn't sure how my hand crimper would work. In the end, I took a gamble and just installed it in the usual manner, using the usual hand crimper dies. All seems well, as I've been able to get a WAAS fix with the aircraft in my basement!

Thanks for the pointers. My take-away is that in the future, I should use the cheaper TNC connector, and either way, the usual BNC hand crimper will do the job nicely.

Thanks to all,

Matthew

Garage Guy · #7 07-22-2010, 04:33 PM

Quote:

Originally Posted by foka4

I guess the 225555-6 is overkill, but it's what Stein provided with my 430W, and in my experience, they usually have a reason for doing things one way vs. another.

I'm curious what the reason is. If you get a chance to ask them (or maybe Stein will jump in here on this thread) I'd be interested to hear the answer.

What connector does he provide for the radio end of the cable? If it's one of those commercial-grade Amphenol male BNC's that they sell, that's a curious combination, exotic mil-spec TNC with rather low-end BNC.

Now, whatever Stein is doing here, I'm sure it works fine. Not criticizing, just wondering what the rationale is.

--Paul

Noah · #8 07-23-2010, 11:01 AM

Just a tip, I needed a right angle TNC connector for my GNS430W antenna, and found a site on Ebay that sold aerospace grade, surplus 10' RG-400 with a right angle TNC connector on one end, and an SMA connector on the other - all for like $5. I just cut off the SMA and terminated it to a regular BNC on the radio end. Very simple and cheap, no additional tools needed!

Bill Dicus · #9 02-19-2013, 05:04 PM

This sounds like a good and economical solution, but the install manual for the GNS430W says a minimum length of 13 feet RG400 is needed to get proper impedance. Any additional connections would add some more impedance. Do you have extra connectors? Thanks for the info! I already messed up one expensive right angle TNC from Stein.

Brantel · #10 02-19-2013, 05:17 PM

The only extra connectors I have are the ones to convert the TNC to regular BNC so I can use the less expensive BNC connectors. The converters are $2.78. BNC connectors are cheap compared to the TNC ones.

I don't suggest adding a bunch of extra connectors in the line just to get the minimum dB of loss. Just add the extra coax.