Thanks, I will give it a try.

The Potentiameter is not adjustable by a screwdriver and looks like a donut with a ring around it that can only be adjusted
by pushing on the ring, like pushing on a cog.  Also, it is located low on the sound board which is stood up on its thin end and the screwed into the chassis. Another words, it's difficult to adjust much less trying to somehow clean it. What do you suggest I try to clean it with, Alcohol ??

Thanks.

Thanks, i found the potentiameter and adjusted the sound.... sounds like yuk !!!
Has anyone tried replacing the speaker or know of a replacement speaker that doesnt sound like
sound is  coming through a  shredded piece of paper !! 
Anyone have the specs on the speaker particularly the OHM rating ??

Thanks.

Well, I finally have time to order a MTH Z-1000 transformer to try the horn and bell on the Williams Diesel 20702, and
i have to turn the  power down on the transformer and then i can barely hear the bell and horn. The transformer is putting out
100 watts but running the diesel at 3/4 speed i cannot hear the bell or horn... any ideas pls.
Also, how do in get in touch with  Joe Satnik on this board so that i can check out a solution posted by 671.

I also have an F3 Diesel Atlantic Coast Line 20702.  I ran it using a 40 powermax transformer with bell and horn, but it ran very slow and the bell and horn was very very quiet, I then ran it using a Lionel 1033 90 watt transformer and it ran great, but because it has no bell or horn I could not test that. Can someone tell me a good transformer to use with this Diesel.?