Ground on rpsma connector?

GoldServe · 06-18-2003

I bought a rpsma connector and was wondering if I needed to solder the ground on the antenna wire to the shaft of the connector? Is ground needed for an antenna?

Thorn · 06-18-2003

A ground is definately needed, but it is formed by the outer shield. The outer shield of the coax cable must be connected to the outer shell of the RP-SMA connector. The inner pin of the connector is NOT connected to the shield, only to the inner conductor.

They cannot touch, or the antenna will be shorted to ground, and you will get no signal.

You might want to look at Times Microwave. They assembly instructions for some of the more common connectors.

On most brands of connectors the proper procedure is to solder the inner connector, and crimp the outer shell. You need a special crimp tool to do this ($80-$120). A pair of pliers won't give the proper crimp, because each size of coax needs the correct size die. Just as an example, my crimper cost $100, and came with 4 different sized dies, for the more common LMR coax sizes.

GoldServe · 06-18-2003

Thank you for your reply! Here is the connector i got:

If you notice, both sides have threads and a solder cup on one side. What i don't get is that there is no place to solder the shielding, or groung and no place to crimp the cable on. I am using this in a laptop mod and plan on taking apart the antenna that dell has inside the laptop and solder to this connector. Any prior knowledge I can obtain before I try this would be great! Thanks!

Thorn · 06-18-2003

That is a panel mount RP-SMA. It is designed to be mounted on a panel or case, as the name implies. i.e. The point that the antenna line exits the radio case.

To use this properly, the center conductor is soldered to the "cup." The shield is soldered to a standard solder-lug washer. The washer is then placed behind the star-washer and nut.

If you are using this to exit the laptop to hook in an external antenna, then assemble it as I've said above. If you are planning on this being outside the laptop for the antenna side, you have the wrong type.

GoldServe · 06-18-2003

Ah...thank you so much. I think understand it now. Solder-lug washer eh...let me see =}

Thorn · 06-18-2003

They look like this. Little hole for the solder, big hole for the connector, but I bet you figured that out.

Rat Shack usually has them, as do most hardware stores.

Here's the real trick to doing this right, especially in a tight space:[list=1][*]Assemble the connector in the panel, tightening the solder lug in place using the nut.[*]Bend the lug out slightly.[*]Solder the shield onto the lug. [*]Solder the center conductor into the cup.[/list=1]

And remember, solder quick and light. You're heating up stuff that does not deal well with heat

GoldServe · 06-19-2003

Okay, i'll try to remember your words of wisdom. Thankfully i have a high temp soldering iron so soldering shouldn't be a problem! Thanks again!

06-18-2003	#1 (permalink)
GoldServe Registered Member Join Date: Nov 2002 Posts: 29	Ground on rpsma connector? I bought a rpsma connector and was wondering if I needed to solder the ground on the antenna wire to the shaft of the connector? Is ground needed for an antenna?

06-18-2003	#2 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,429	A ground is definately needed, but it is formed by the outer shield. The outer shield of the coax cable must be connected to the outer shell of the RP-SMA connector. The inner pin of the connector is NOT connected to the shield, only to the inner conductor. They cannot touch, or the antenna will be shorted to ground, and you will get no signal. You might want to look at Times Microwave. They assembly instructions for some of the more common connectors. On most brands of connectors the proper procedure is to solder the inner connector, and crimp the outer shell. You need a special crimp tool to do this ($80-$120). A pair of pliers won't give the proper crimp, because each size of coax needs the correct size die. Just as an example, my crimper cost $100, and came with 4 different sized dies, for the more common LMR coax sizes. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

06-18-2003	#4 (permalink)
Thorn Did you do the math? Join Date: Apr 2002 Location: Villa Straylight Posts: 10,429	That is a panel mount RP-SMA. It is designed to be mounted on a panel or case, as the name implies. i.e. The point that the antenna line exits the radio case. To use this properly, the center conductor is soldered to the "cup." The shield is soldered to a standard solder-lug washer. The washer is then placed behind the star-washer and nut. If you are using this to exit the laptop to hook in an external antenna, then assemble it as I've said above. If you are planning on this being outside the laptop for the antenna side, you have the wrong type. __________________ Thorn "Read Altas Shrugged. Compare it to today. Repeat as necessary"

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06-18-2003	#3 (permalink)
GoldServe Registered Member Join Date: Nov 2002 Posts: 29	Thank you for your reply! Here is the connector i got: If you notice, both sides have threads and a solder cup on one side. What i don't get is that there is no place to solder the shielding, or groung and no place to crimp the cable on. I am using this in a laptop mod and plan on taking apart the antenna that dell has inside the laptop and solder to this connector. Any prior knowledge I can obtain before I try this would be great! Thanks!

06-18-2003	#5 (permalink)
GoldServe Registered Member Join Date: Nov 2002 Posts: 29	Ah...thank you so much. I think understand it now. Solder-lug washer eh...let me see =}

06-19-2003	#7 (permalink)
GoldServe Registered Member Join Date: Nov 2002 Posts: 29	Okay, i'll try to remember your words of wisdom. Thankfully i have a high temp soldering iron so soldering shouldn't be a problem! Thanks again!