Thompson dvb recorder?

Problem with aerial connection
My aerial connection works directly on my Hitachi tv
but when I plug the aerial connection into my Thompson dvb recorder I cannot get an aerial connection signal straight to my Hitachi tv without it being completly switched on although I previously did get this aerial connection just by pluging the aerial connections in and having only the red light only showing on the recorder .
If I turn on the recorder to get the green/yellow light on then a connection is being made to my tv ie. whilst going via the recorder .
Anyone can solve this problem