Connecting ladder line from folded dipole to radio!

Measured out a piece of HLF200 coaxial cable with just enough length to connect radio to the ladder line outside. It was 183 cm long. Stripped the outer protective sheath at one end using a wire stripper. Pre-crimped PL 259 connector was there on the other end.

Small piece of dielectric and a foil outside it was also removed for connecting with ladder line. Twisted the outer shield in preparation for soldering to the ladder line. The cut end of the cable without the PL 259 connector was taken outside the shack.

A piece of heat shrink sheath was slided over the end of one of the ladder line wires and then it was soldered to the inner conductor of the coaxial cable. Heat shrink was shrinked using the soldering iron as I do not have a blow pipe.

Heat shrink was moulded on to the wire by gradual application of heat from the soldering iron so as to fit fairly well on the wire.

Outer conductor of the coaxial cable was soldered to the other wire of the ladder line and heat shrink fixed over it, though it could not cover the whole joint.

The joint was further secured with silicone tape bought online for both insulation and waterproofing. You can also see my grape vine in the background. We bought the silicone tape from Amazon: https://amzn.to/44qVBfE. Please note that if you buy from this link, Amazon will pay me a small bit as an affiliate, with no additional cost to the buyer.

Here you can see a portion of the ladder line going up from the shack. Parts of my other wire antennas can also be seen in the background.

Came inside and checked the resistance between the inner and outer parts of the PL 259 connector. As expected, a low DC resistance of 20 ohms was noted. That is because of the full DC path of the folded dipole which is in direct continuity with the ladder line, coaxial cable and the PL 259 connector. But for RF the impedance will depend on the test frequency.

The antenna feedline system could be easily tuned to 14 MHz and 28 MHz amateur radio bands with ATU-100 External antenna tuner. To get matching on 21 MHz I had to used the internal antenna tuner of FT-710 in series. When this was done, ‘AUTO’ function in ATU-100 was disabled as a precaution, as explained earlier. A homebrew common mode choke was also in place between the ATU-100 and the PL 259 connector of the feedline. It was not possible to tune to 7 MHz or 3.5 MHz. Next step will be to try optimizing the performance by increasing the height of folded dipole as much as possible and keeping the ladder line perpendicular to the antenna from the feedpoint. Those are easily said than done because of mounting constraints and interaction with other antennas already in place. I may have to bring down my fan dipole which has not been functioning well after seepage of rainwater.