Andy: Agreed. I have a LDG tuner that I used to carry for use with the 817. I stopped carrying it because the linked dipole is such a benign and reliable antenna.
My antenna has no brand being home made, but the principle is the same.
Kjetil: As your antenna is new you have no reference point. I think it would be helpful to choose a band and try to find where it is resonant. An antenna analyser (impedance analyser) is the most convenient way of doing that, but your radio and an swr meter should indicate whether the resonance is higher or lower than the intended band. Some radios have an inbuilt swr curve checker.
The other thing worth checking is the antenna length. There is no loading, so the length on each band should be close to 95% of the half wave length. Divide 150 by the frequency in mhz then you have the half wavelength in metres. Reduce by 5% for end effect.
Start at the highest frequency band. The link for that band should be open. Measure the length from that link through the feedpoint and over to the corresponding other link. That length should be within 50mm of the calculated half wave.
On lower bands, all links between the feedpoint and the half wave point for that band should be closed. The same calculation can be done for each band.
A high swr on antenna that is normally perfect, indicates something is broken. The health check on connectors, antenna centre connections and coax damage should be the first resort. Omitting strain relief at the feed point is a way to damage the coax feedline, or damage the connection between cable and connector.
Antenna height: Raising the antenna should have two effects, one is the slightly higher impedance with extra height. The other is reduced ground losses which to some extent reduces the feed impedance, compensating for the height change. I've used my linked dipole at various heights and have not noticed any significant change in resonance or impedance. The only times I see high swr is when I have left a link connected when it should be open, or vice versa.
73 Andrew VK1DA VK2UH