Thank you for the advice.It seems I misunderstood the maximum number of slots in channel 38 which looking at the frequency chart is 13 if we use bank 7, 9,11 or 12 rather than the bank 1 we are using at the moment for which the maximum is 12.I must admit I had forgotten about channel 65 and the 2014 published Sennheiser chart predates it - the changes having been made in 2015.We can access some older G3 units that will tune down to 830Mhz. Sennheiser list three slots in the gap between 830Mhz and 832Mhz. If I can get that to work I have achieved my 15 plus a spare and my Director is happy.Thanks again for pointing me in the right direction.David Ashton