The Mellotron Group

Magnetism... we all are concerned about it and the damage that magnetized  
heads can do to our tapes. How many of you that have the old steel capstans  
check them for magnetism? You should. I check every one that comes through 
my  shop. Some have very little some have a fair amount. Tonight I checked 
one that  really surprised me. Using a magnetometer it on it revealed that it 
was  substantially magnetized... more than ten time worse than the tape 
heads, and  they were in severe need of demagnetization. Unfortunately, using a 
cheap  demagnetizer isn't going to solve the problem, but it is one that 
all of you  must consider. You can demag your heads every day, but a 
magnetized capstan can  seriously degrade your tapes.
 
Magnetometers are not very expensive. They are handy to have and can tell  
you how well you demag your tape heads, and can show you where else magnetic 
 fields are in the tape path. I recommend that every serious Mellotron 
owner  should get one. Also, if you don't have a demagnetizer capable of 
draining the  magnetism from your capstan, there are commercial facilities that can 
do it for  you.
 
Frank