Wire & connectorsKeep the moduleUnplug and unscrew
Antenna pigtail
Also called U.FL, IPEX, Wi-Fi antenna.
The tiny coaxial lead from a router or laptop Wi-Fi card to its antenna. The connector is the useful part if you work on radios. The antenna is a length of wire tuned for 2.4 GHz, not a general-purpose aerial.
If you are new to this category
Wire and plugs are how power and signals move. The insulation is the safety, not the copper. Ethernet cable is fine for small signals and low voltage. It is not a substitute for a power cord. A connector you can unplug is worth more than a wire you have to solder every time.
Match the plug that came with the brick. Center-positive is common and not universal. The drawing on the label is a map: the dot is the center, the ring is the outside.
The drawing on the brick is the polarity. A dot inside a C-shaped ring means the center is positive when the plus sign points at the dot. Measure anyway. The two common hole sizes, 2.1 mm and 2.5 mm, almost fit each other and that is how the center pin gets bent.
| What to look for | Usual figure |
|---|---|
| Connector | U.FL / IPEX. It is rated for very few mating cycles. Do not use it as a headphone jack. |
| Antenna | A PCB trace or a dipole for the band of that router |
Volts are electrical pressure, amps are how much current is flowing, and ohms are how hard the part resists that flow. A higher voltage than the part was built for is how salvage parts die on the bench. If a cell in the table says “read the stamp”, that stamp is the whole specification.
What people actually use it for
- Replacing a broken laptop antenna lead
- A 2.4 GHz antenna of the same type
Leave this one when
The center pin is bent. These connectors do not forgive that.
Buying a new one is the better idea when
A new pigtail. The connector is the expensive annoyance, and a new one is not very expensive.
How to tell if this one still works
Continuity of shield and center, open between them. Then the original device, if it still runs.
Tools you will want: Meter, Gentle fingers.
Words on this page
Short meanings, so the rest of the entry is readable if you are not already doing this every weekend.
- continuity
- A meter mode that beeps when two points are connected. It is how you map a switch: beep, then click, then see if the beep changes.
Where people actually find it
1 notes, most useful first. “Leave it” means the part is in that machine and you should not take it: it is dangerous, worn out, or only useful if you already know that exact repair.
| From | Call | How many | How often | Where it sits |
|---|---|---|---|---|
| Router or modem | Worth it | 1–3 | usually | From the board to the antenna. |
- In this particular machine
- U.FL to a small dipole.
- Where to look
- From the board to the antenna.
- How to get it out
- Pop the connector straight.
- The condition to expect
- Good if the center pin is straight.