Sir, - Radio Eireann has recently done a serious disservice to the elderly, the disabled and those who are rarely able to get to Church. It has transferred the two Sunday morning services from the FM band to medium wave.These services frequently come from small country parishes and involve considerable work by the clerics, the parishioners and those in charge of the music.On VHF, the very high frequency used for the carrier wave can accommodate a wide range of frequencies which are modulated on to the carrier. The quality of reception throughout most of Ireland is good and the tone is excellent. On medium wave, the much lower frequency of the carrier greatly reduces the quality of tone available and this type of modulation can often be interrupted by whistles and clicks.There can only be one reason for this change of policy. Programmes now broadcast on the FM band can be interrupted for commercial advertising, which was not the case when the services were broadcast on FM.I am partially disabled and I often greatly enjoyed the Sunday morning. - Yours, etc.,J. England,Donnybrook,Dublin 4.