Hey Brookes
Interesting product, will have to do some research.
Standard method I use is to setup the TV to where I think it will work then do an Auto-Tune where the TV finds the best channels available based on signal strength.
Then I find ABC on the analog spectrum and do the old "how is it now?" to someone inside while I turn it around to find the best signal/less fuzz. (This was with the old van with the non-wind up antenna)
Lastly, another auto tune on the TV that sorts out the digital channels and gives us the best for what we will get. Also, I recently upgraded the antenna (before selling the van) to a boosted (powered) Wyngard. Is this the case here?
The main thing is that the TV will be the best guide for signal reception since it is that does the receiving, not the signal strength meter. There could be slight differences there between the two so if all else fails, trust thy TV.
If you are having other issues then I would suggest checking all your connections and making sure there is no corrosion on the connectors or kinks in the cable. Even a slight bit of oxidisation can take away a few dB from the signal strength.
Cheers mate, hope you have some success with this.