Need some help with my Ramsey DDF1. It comes with telescopic antennas and my son has accidentally stepped on and broken one. I'm taking the opportunity to replace them with a SMA connector and calibrated rubber ducky antennas instead. However the telescopic antennas screwed directly to the PCB. Am I correct in assuming that the core of the SMA connector is just soldered to that?(isolating the body of the connector from it)
Here is where you'll find your answer.
Antenna mounting begins on page 17, and on page 19 it shows how the whip antennas are connected to the circuit board.
And your answer is Yes, the nut that holds the whip is connected to the circuit board. So the middle of the SMA connector (core, as you called it) would be soldered where the screw is. The surrounding part would be connected to the shield of the coax.