Precision custom cable assemblies?

[BMDaug]

Hey everyone, I’m looking for recommendations on places where I can purchase some custom cable assemblies. The one I need the most is a bulkhead N female to a TNC male that’s about 5 1/8” from the end of the connected TNC connector to the panel that the bulkhead N female mounts in. I’m also looking for recommendations on what cable I should use in this scenario. Obviously, I want it to be low loss, but at this length, I’m not sure how much the type of cable matters. The cable will be handling 50W maximum.

I can trade precision in the length of the cable for flexibility of the cable, but if I’m going to use something fairly heavy, it needs to be reasonably precise so that I can stay within the rated bend radius specifications of the wire. I’m running from a transceiver to a panel on the enclosure I’m building. I know I can make this, but I’m not tooled up for it and crimp tools are expensive.

Any advice on websites or stores I can order something like this, as well as what type of coax I should be looking at would be greatly appreciated!

Thanks,
Brian

 

[rks1257]

ABR Industries — Coax Cable, Assemblies, Connector Supplies

Great products and service.

 

[mmckenna]

RG-400 cable, not to be confused with LMR-400.

RG-400 is a low loss, well shielded cable. It's often used for jumper applications, test cables, etc.
Bend radius is 1 inch. I've seen it used in a lot of internal applications. I think I have some Motorola cables made out of RG-400 that were inside XTL-5000 consolettes.

RG400 RF Coax Custom Cable

RG400 RF Coax Custom Cable

www.shireeninc.com

Would help to know what the exact application is, though.

 

[bearcatrp]

I sometimes go with Pasternack. Not cheap though but usually what I am looking for that no one has.

Cables, Coaxial Cable, Cable Connectors, Adapters, Attenuators, Microwave Parts

Pasternack carries a huge selection of microwave parts, RF parts, cables, connectors, modulators, adapters, attenuators plus much more. Bulk quantities shipped same day.

www.pasternack.com

 

[BMDaug]

Thanks for the replies guys! The cable is just to bring the antenna connector for a manpack out to the bracket it will mount to. I’m debating whether to make a short loop, or try to make it as tight as possible. If I use, say, a 24” section, everything will be super simple and tolerance becomes unimportant. I don’t think this will create significant loss based on the RG-400 spec sheet. Will having a 24” length of cable positively affect VSWR?

The antenna mounting bracket is bolted to the mobile radio where the mounting tray would usually bolt, so the radio chassis is providing a ground plane. I’m currently using a 5’ length of LMR-240 between the radio and a female to female bulkhead mounted in the bracket. I definitely want to remove the female to female bulkhead and just have one end of the cable terminated directly to a female N bulkhead, and I’m sold on the RG-400, but I’m still working on the best length.

Thanks,
Brian

 

[mmckenna]

Without a good ground plane, all bets are kind of off. Would be very difficult for someone here to tell you if you'd see an improvement with a certain length of cable.

The RG-400 is nice stuff, but it's such a short run, I don't think you would be able to notice any difference between that and RG-58. I'd be more concerned about flexibility. RG-400 is a bit more stiff than RG-58.
If it is the challenge of building this setup that you are into, then absolutely, have some shop build a custom RG-400 cable with the right connectors, heat shrink, and you'll be good to go.
I'd not worry about an extra few inches of cable, there's just not enough loss there to make a difference. I'd be more concerned about routing and protecting all the connections. For survivability in a portable application, the more flexible cable and a loop to allow flex would be my choice.

 

[BMDaug]

Without a good ground plane, all bets are kind of off. Would be very difficult for someone here to tell you if you'd see an improvement with a certain length of cable.

The RG-400 is nice stuff, but it's such a short run, I don't think you would be able to notice any difference between that and RG-58. I'd be more concerned about flexibility. RG-400 is a bit more stiff than RG-58.
If it is the challenge of building this setup that you are into, then absolutely, have some shop build a custom RG-400 cable with the right connectors, heat shrink, and you'll be good to go.
I'd not worry about an extra few inches of cable, there's just not enough loss there to make a difference. I'd be more concerned about routing and protecting all the connections. For survivability in a portable application, the more flexible cable and a loop to allow flex would be my choice.

Thanks for the great reply! I think I’ll just do a 3’ RG-400 TNC male to N female bulkhead. It’ll allow really clean routing. I sleeve everything and use some of the mounting studs with rubber coated cable clamps to ensure strain relief. It’s been lots of small fabrication and fitment. I was checking in to a bunch of nets with it tonight and snapped this pic.

 

[BMDaug]

Here’s the inside…

 

[AK9R]

I've purchased cable assemblies using RG400 from Field Components in the past and had good service. I don't know how they will do with a precise short length, but they might be able to fix you up.

Here's an assembly using the connectors you specified with RG400: N Female Bulkhead on RG400 to TNC Male Cable Assembly

 

[AK9R]

The RG-400 is nice stuff, but it's such a short run, I don't think you would be able to notice any difference between that and RG-58. I'd be more concerned about flexibility.

RG-316 maybe?

 

[sonm10]

Just received a shipment of LMR-240 from MPD Digital (USA Coax). Very impressed with the quality.
Times Microwave LMR-240 Cable build - Custom Cables (usacoax.com)

 

[BMDaug]

I went with the RG-400… I went with a few feet for clean routing and flexibility.

Thanks everyone,
Brian

Edit: I might be picking up some of that 240 for my hanging dipole… still trying to decide.