[Heathkit] Heathkit Digest, Vol 99, Issue 22 - stuck cores

[G3OOU at aol.com]

Hi Jack
 
My experience is that the very old Heath trimming tools can crack the cores 
 if the plastic has shrunk a bit over the years. I have managed to move 
some  difficult cores using a metal allen key as it is a much better fit. 
However, I  suggest that you look at the cores with a magnifying glass to see if 
they are  already cracked. If they are you can pick them out in bits using a 
sharp scriber  or you might be able to drill them out (slowly) or file them 
out as they  are usually dust iron which is much softer than ferrite.
 
I have tried silicon tap grease as a core holding compound as it does have  
some lubricating properties and is non-conductive. Many years ago the 
company I  worked for used a thixotropic silicon grease to hold cores in place in 
mobile  equipment - it worked very well but needed gentle initial pressure 
to get it  moving again..
 
73

Bob

Bob F Burns
C Eng,  FIET, MSE
Amateur Radio Callsign: G3OOU
Registered RSGB  Instructor
G-QRP Member No: 6907; Zone: 14, QRA: IO91WH; WAB:  TQ25
Secretary of Crystal Palace Radio & Electronics Club: _www.g3oou.co.uk_ 
(http://www.g3oou.co.uk/) 
Technical web site: _www.qsl.net/g3oou_ (http://www.qsl.net/g3oou)