Just unplugged the lead out of the amp booster and connected direct to wall socket in main room and that allowed all channels to be tuned to the Bravia in backroom , so I spose that points to the booster as when I reconnect as before the HD channels are still showing but barely a picture and amost total breakup , now showing the correct positions ( 50-54 ) .
Is it worth upgrading the signal booster and what to ?
Played around at back of Bravia with aerial lead and hey presto good pic and resumption of HD channels , fingers crossed

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Julian