Help With DIY Antennas - Coax Connectors!!

bbognerks · 09-18-2003

Well, my friend and I are preparing to construct 4 omni's and 1 yagi for our wireless gear. However, being dumb, we only got the exact amount of n-connectors and other connectors from fab-corp. Basically I don't want to screw anything up so I was hoping you could all inform me how to connect some lmr 400 to these things correctly and without a crimp tool. I searched the forums for this topic, but either I am bad at searching, or it hasn't really been covered. Thanks for all your help.

I got the Connectors from fab-corp and they are the crimp on style. They seem to have a collar type thing and a center pin and the bulk of the connector itself. It seems like I can figure these out. The way I was gonna do it was crimp the center pin, then put the braid shield part on the outside along with the rubber over it, then slide the collar over the assembly and crimp. Is that right.

Also we got 2 INLINE female n-connectors. They have like 6 pieces that all fit inside, 1 is a white mini life savers looking thing, then a metal collar thing then another metal washer thing, then a rubber piece, then another washer thing and then the end that screws on. That is the one that is really stumping me.

If you could provide any links on how to do this with pics, that would be awesome. Thanks.

Thorn · 09-19-2003

Without knowing the manufacturer of the connectors it is very difficult to say exactly how to assemble the connectors. Check the Times-Microwave, Connex and Ampherol sites for some assembly drawings which may help. Most go together in a similar manner, but differ in the fine details.

You're setting yourself up for a fall without the proper tools. You should have:

Crimp tool
Coax Stripper
X-Acto or other razor knife
Soldering station
Fine scale ruler

Buy a crimp tool. You can get along with out the stripper, but just being careful with the knife. But assembling without a proper crimping will mean that the connection probably will not work. If it does work, the connection will be poor.

Poor connection = High SWR = Signal loss.

Using pliers (hammer, chisel, or any other tools besides a proper crimper) will only result in a bad crimp.

Bad crimps = Poor connection = High SWR = Signal loss.

On some brands of connectors the center pin may be crimped, but generally the center pin is soldered. Usually there is a small weep hole on the side of the pin, 90º to the center conductor hole to assist in soldering. Crimping the center pin may work, but soldering is preferred for those designed for it.

The inner conductor, inner dielectric, braid and outer cover all have to be trimmed back to proper lengths, which is dependant on the specific connector type and brand.

Buy the proper tools, or find someone who has them and is willing to help.

bbognerks · 09-19-2003

Well, if the tools weren't so expensive I wouldn't mind buying them. The whole point of building our own was to save money. I was looking to rent some crimpers but this stupid city doesn't have anything. I can't even find lmr 400 crimps for sale anywhere. Also, if the stripback and instructions are dependent on the manufacurer, why the hell doesn't fab-corp provide this info. ARGH!!! So Irritating. I'll see what I can find I guess. Thanks for the reply.

Mr.White · 09-19-2003

If you want to make ends for LMR-400 but not have to buy tools, order up some solder-type connectors.

The N males are 2 piece connectors and the only tools required are a sharp utility knife and a good soldering iron. They aren't as good as crimp connectors but don't require all those tools. See if the Fab-corp guys will let you return them for solder types or check your local 2-way radio shop.

I used to used solder types a lot but they just aren't pratical for the number of connectors I need to make in a day. If need be, I can fish some out and take pictures of where to cut the sheilding and so on.

Thorn · 09-19-2003

Quote:

Originally posted by bbognerks
Well, if the tools weren't so expensive I wouldn't mind buying them. The whole point of building our own was to save money. I was looking to rent some crimpers but this stupid city doesn't have anything. I can't even find lmr 400 crimps for sale anywhere. Also, if the stripback and instructions are dependent on the manufacurer, why the hell doesn't fab-corp provide this info. ARGH!!! So Irritating. I'll see what I can find I guess. Thanks for the reply.

You're welcome.

I certainly understand that the point of DIY is to save some money. However, with the connectors don't work correctly (especially if they cause major signal losses), you'll be wasting your money and time as well as racking up huge amounts frustration.

Two suggestions in addition to what Mr. White said: Find a two-way radio shop (check the Yellow Pages) or a local Ham. Either or both may have the tools and if you ask nice, may let you use them.

bbognerks · 09-19-2003

Well I just decided to order some crimpers. I'll just have to make more antenna's and sell them on ebay or something. Thanks for all the suggestions.

bbognerks · 09-19-2003

This is just crapfabulous. The crimpers I ordered are on backorder and I really want to get the antennas done on monday or tues. If anyone has any other ideas they would be much appreciated. My friend and I were thinking of fashioning our own crimps from the adjustable socket wrench from craftsman.

razta · 09-19-2003

Its prob too late for any other company to ship a crimper to you, but you can try again monday with:
www.ydi.com
www.electro-comm.com

bbognerks · 09-20-2003

I have one more thought. In the event that I can't get my hands on some crimpers, would it be ok to solder the outer shielding on the connector, then slide the crimp collar over it and glue it in place?

Thorn · 09-21-2003

It may work. However, the shell may be difficult to solder. Since they are designed to be crimped, YMMV.

09-18-2003	#1 (permalink)
bbognerks Registered Member Join Date: Sep 2003 Location: Wichita, KS Posts: 14	Help With DIY Antennas - Coax Connectors!! Well, my friend and I are preparing to construct 4 omni's and 1 yagi for our wireless gear. However, being dumb, we only got the exact amount of n-connectors and other connectors from fab-corp. Basically I don't want to screw anything up so I was hoping you could all inform me how to connect some lmr 400 to these things correctly and without a crimp tool. I searched the forums for this topic, but either I am bad at searching, or it hasn't really been covered. Thanks for all your help. I got the Connectors from fab-corp and they are the crimp on style. They seem to have a collar type thing and a center pin and the bulk of the connector itself. It seems like I can figure these out. The way I was gonna do it was crimp the center pin, then put the braid shield part on the outside along with the rubber over it, then slide the collar over the assembly and crimp. Is that right. Also we got 2 INLINE female n-connectors. They have like 6 pieces that all fit inside, 1 is a white mini life savers looking thing, then a metal collar thing then another metal washer thing, then a rubber piece, then another washer thing and then the end that screws on. That is the one that is really stumping me. If you could provide any links on how to do this with pics, that would be awesome. Thanks.

09-19-2003	#2 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,358	Without knowing the manufacturer of the connectors it is very difficult to say exactly how to assemble the connectors. Check the Times-Microwave, Connex and Ampherol sites for some assembly drawings which may help. Most go together in a similar manner, but differ in the fine details. You're setting yourself up for a fall without the proper tools. You should have: Crimp tool Coax Stripper X-Acto or other razor knife Soldering station Fine scale ruler Buy a crimp tool. You can get along with out the stripper, but just being careful with the knife. But assembling without a proper crimping will mean that the connection probably will not work. If it does work, the connection will be poor. Poor connection = High SWR = Signal loss. Using pliers (hammer, chisel, or any other tools besides a proper crimper) will only result in a bad crimp. Bad crimps = Poor connection = High SWR = Signal loss. On some brands of connectors the center pin may be crimped, but generally the center pin is soldered. Usually there is a small weep hole on the side of the pin, 90º to the center conductor hole to assist in soldering. Crimping the center pin may work, but soldering is preferred for those designed for it. The inner conductor, inner dielectric, braid and outer cover all have to be trimmed back to proper lengths, which is dependant on the specific connector type and brand. Buy the proper tools, or find someone who has them and is willing to help. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

09-19-2003	#4 (permalink)
Mr.White OH such tacos will I give Join Date: Oct 2002 Location: Minnesota Posts: 1,049	If you want to make ends for LMR-400 but not have to buy tools, order up some solder-type connectors. The N males are 2 piece connectors and the only tools required are a sharp utility knife and a good soldering iron. They aren't as good as crimp connectors but don't require all those tools. See if the Fab-corp guys will let you return them for solder types or check your local 2-way radio shop. I used to used solder types a lot but they just aren't pratical for the number of connectors I need to make in a day. If need be, I can fish some out and take pictures of where to cut the sheilding and so on. __________________ A good way to threaten somebody is to light a stick of dynamite. Then you call the guy and hold the burning fuse up to the phone. "Hear that?" you say. "That's dynamite, baby." -Jack Handey

09-19-2003	#8 (permalink)
razta PTP to PTMP Join Date: Jul 2002 Location: Tucson Posts: 150	Its prob too late for any other company to ship a crimper to you, but you can try again monday with: www.ydi.com www.electro-comm.com __________________ <><><><><><><><><><><> Razta

09-21-2003	#10 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,358	It may work. However, the shell may be difficult to solder. Since they are designed to be crimped, YMMV. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

09-19-2003	#3 (permalink)
bbognerks Registered Member Join Date: Sep 2003 Location: Wichita, KS Posts: 14	Well, if the tools weren't so expensive I wouldn't mind buying them. The whole point of building our own was to save money. I was looking to rent some crimpers but this stupid city doesn't have anything. I can't even find lmr 400 crimps for sale anywhere. Also, if the stripback and instructions are dependent on the manufacurer, why the hell doesn't fab-corp provide this info. ARGH!!! So Irritating. I'll see what I can find I guess. Thanks for the reply.

09-19-2003	#6 (permalink)
bbognerks Registered Member Join Date: Sep 2003 Location: Wichita, KS Posts: 14	Well I just decided to order some crimpers. I'll just have to make more antenna's and sell them on ebay or something. Thanks for all the suggestions.

09-19-2003	#7 (permalink)
bbognerks Registered Member Join Date: Sep 2003 Location: Wichita, KS Posts: 14	This is just crapfabulous. The crimpers I ordered are on backorder and I really want to get the antennas done on monday or tues. If anyone has any other ideas they would be much appreciated. My friend and I were thinking of fashioning our own crimps from the adjustable socket wrench from craftsman.

09-20-2003	#9 (permalink)
bbognerks Registered Member Join Date: Sep 2003 Location: Wichita, KS Posts: 14	I have one more thought. In the event that I can't get my hands on some crimpers, would it be ok to solder the outer shielding on the connector, then slide the crimp collar over it and glue it in place?

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