Poor reception

I wonder if anyone has had a similar experience and if so what was the remedy.
My Symbol has a Status 315 'flying saucer' type tv aerial with a Pre-Amp? or powers supply in the wardrobe.
 for the third time we were at a site where everyone else seemed ok and our reception at best was broken up or failed altogether.
The site warden at the last site said there was no difficulty at that site.
The TV is brand new and at a site virtually looking at a transmitter seemed ok.
I realise the aerial is omni-directional and probably has less than half the gain of a small directional, but with a pre-amp I would have thought it would be ok most of the time.
Any suggestions? also is there a directional type that could be fitted in the same place on the roof?
Thanks for reading this.
Regards
Viv

Hi and welcome to the forum from Bridlington
Boaby

Check your flylead.  I've had several leads which were useless but I blamed the aerial. Buy good quality lead and chances are it will improve no end. Omnidirectional aerials were useless during the digital changeover period but once the changeover was complete and signals doubled in strength, then the aerials improved greatly. Wherever you are, avoid pitching close to trees or buildings in direct line to transmitter. 
Our Nuevo has a directional aerial and we can suffer poor reception with that so don't be in too much of a hurry to replace your omnidirectional.

I have had exactly the same problems with fly leads at home. Funnily enough it was the expensive one that was the problem and the cheap one that worked.

Peter