Reddit reviews 3 ft Low-Loss Coaxial Extension Cable (50 Ohm) SMA Male to N Male Connector, GEMEK Pure Copper Coax Cables for 3G/4G/5G/LTE/ADS-B/Ham/GPS/WiFi/RF Radio to Antenna or Surge Arrester Use (Not for TV)
We found 1 Reddit comments about 3 ft Low-Loss Coaxial Extension Cable (50 Ohm) SMA Male to N Male Connector, GEMEK Pure Copper Coax Cables for 3G/4G/5G/LTE/ADS-B/Ham/GPS/WiFi/RF Radio to Antenna or Surge Arrester Use (Not for TV). Here are the top ones, ranked by their Reddit score.
✔Connector: All-copper SMA Male to N Male adapter.✔Connect from SMA Equipment to N-Style Antennas, receivers, meters, radio transmitters and WiFi Signal Booster Repeater.✔3 feet(1 Meters) Low-Loss S-LMR240 Size Coax, Impedance: 50 ohm. S-LMR240 offers a significantly larger center conductor and supports better signal retention for longer cable runs and higher frequency use.✔Double Shielded Coax extension cable assemblies are constructed with top quality extremely low-loss S-LMR240 cable and gold plated connectors. High frequency low loss and low impedance, heat Shrink on Both Ends.✔Compatible with all SMA-based equipment including modems and routers & WiFi Signal Booster Repeater from Cisco, Digi, Cradlepoint, Proxicast, Pepwave, Sierra Wireless, Sixnet/Red Lion and many others.
A hackrf one can do 2.4 GHz and directional antennas are easily found online. You would also need an adaptor like this one
Then you could use a laptop running GQRX or SDR Sharp to show you the signal strength of 2.4 GHz signals in the direction of the antenna. Turn off your phone WiFi and laptop WiFi.
See if you can find any ham radio operators in your area, they often know how to find a transmitting beacon (it’s called a fox hunt).