I got a chance to get out to the plane today so here is what happened and I'm still baffled. I checked the connections to the antenna and KMA24 and all seemed tight and clean. I took off on 13 asking the tower ot allow me to cross the OM(TUNGG) 31 approach at 1500 feet. No tone or light. I had them vector me directly over TUNGG several times because my ADF is old and think has bitten the dust. It is original one for 1968. Anyone know an ADF that will fit in a round instrument hole? Anyway I then had them vector me to ADLER which is OM for 13 and as I approached the airport environment I began to pick up first the MM tone then closer I got the MM light on my way to ADLER where I got the OM light and tone. I climbed to 6000 feet and made a pass over ADLER where I got tone and light on high Sens and none on low sens and passing by airport environment I got tone and light for MM on high sens and none on low sens and was vectored once again to TUNGG and no light or tone. I asked tower if anyone else had commented on this condition and the answer was no. Passing over TUNGG at 6000 yielded no other result. I am perplexed.