Joining lengths of 450 ohm "window line."

[VK4WDM]

I have several lengths of good quality 450 ohm "window line" that I would like to join together by twist and solder. Is this likely to cause a significant change in impedance?

73

Wayne VK4WDM

[VK5ZD]

Assuming the length of the join is a small fraction of a wavelength (i.e. you're using it on HF), then the answer is no.

[VK3HJ]

You'd have to change the spacing and/or conductor diameter significantly before the impedance changes appreciably.
Run through the calculations to illustrate. You'd do well to cover the solder joints and exposed conductors with something like liquid electrical tape (avail from Jaycar, etc.) or moisture will wick through.
Take care with mechanical considerations. I'm sure you've seen this type of parallel feedline flap madly in the wind, without a good twist in the feedine. The joins will be at risk of breaking.
This type of feedline is good for portable and temporary use. For permanent installation, I prefer to construct with copper wire and spacers.
73,
Luke VK3HJ

[ZL4PW]

I joined mine with 4mm or 6mm electrical sleeve crimps, then ran solder into them and taped over each join. If you make the join in the window section, then it will maintain its shape and allow it to twist freely.