Notice something missing?
Yes, the antenna has been cleanly ripped out of this poor receiver. Time to get out the soldering iron...
WARNING: This and other DIY projects are purely "at your own risk". If you are at all uncomfortable or inexperienced working with electronics, please reconsider doing the job yourself.
The antenna connects to the round soldering pad and the vertical strip on the left side of the receiver, shown in the following picture:
First clean off the soldering pads, removing any left-overs from the original antenna. De-soldering braid is very useful for this job.
The antenna is simply a 19 cm long piece of 1.2 mm thin COAX wire. I found some spare wire in an old Wi-Fi equipment that was no longer in use.
On one side carefully strip off 2 mm of insulation using a sharp hobby knife. This exposes the shielding braid.
Unravel the braided wires and form two neat bundles on opposite sides.
The following picture shows how the wire will be mounted on the receiver.
Now strip of approximately 0.5 mm of the insulation of the centre wire. Then pre-tin the centre wire as well as the shielding lobes.
Solder on the centre wire, then each side of the shielding wires.
This completes work on the receiver, but we still need to form the actual antenna.
Strip off exactly 26 mm of the outer insulation. You need to be very precise as this affects the quality of the antenna.
Unravel the braid and cut it off exactly at the remaining insulation. This completes the antenna.
Do perform a range check to ensure it is working fine!