For people who want as much DAB signal as possible (and most people don’t need a high gain DAB aerial) we stock a 5 element DAB aerial. There are even larger DAB aerial available with even more elements, but, bearing in mind DAB aerials would usually have to be end mounted* I really don’t think any marginal increase in gain (and it would be marginal due to the law of diminishing returns….) is worthwhile for the resulting even larger wind load.
I would estimate that the 5 element DAB aerial would give about 2dB more gain than a 3 element, i.e. about 5dBd.
* In the case of this aerial we would recommend end mounting it because mid mounting would put the pole between the (vertically polarised) elements thus negatively affecting the gain.
We didn’t test the DAB 5 (we didn’t stock it when the tests were done ! ) , but I’d have thought its relative results for the table below would be :
DAB directional performance – EXCELLENT plus
DAB omni performance – Variable moderate to good
FM directional performance – Moderate
FM omni performance – Variable poor to moderate