| BLAENPLWYF 
          
            
              | Channel
                3H | Max
                ERP: 3kW (directional) |  
              | Vision
                carrier: 56.75MHz | Sound
                Carrier: 53.25MHz |  
              | 
 |  
              | The
                field strength contours on this map represent average values
                with the E.R.P. indicated; variations of as much as 3:1 in field
                strength may occur at individual points. The 0.1mV/m contour
                should not be interpreted as a rigid boundary of the area
                served, since the quality of reception obtainable would have
                depended on local conditions. Fading and interference may at
                times have been experienced in the outer areas served and also,
                in difficult locations, nearer the transmitter. |  
              | BBC
                Engineering information sheet 2926 (1) | September
                1968 |  |