Removing chrome IF shields on Philharmonic

[Ken Carr]

I have a question regarding the chrome shields that cover the IF Coils on the Philharmonic. I need to remove these so as to replace the pair of capacitors in each one.

I removed (de-soldered) the grid caps from the pair of wires that exit the shield. I then pushed them inside a bit, but not all the way. I wanted to be sure I could pull them back out if the shield did not give way.

When I tried to lift the shield off , with plenty of force, it only came up a small amount. Is this because I must push those wires in completely (they still appear slack when I lift on the shield) or is there some under-chassis fastener holding these down?

I just don't want to force anything and regret it later.

[Scott Seickel]

The cover should come right off when the wires go in.

You may need to be creative to get the wires back out.  I would just solder another small piece of wire end to end to enable you to pull the grid wire back out. 

[Ken Carr]

OK, Scott. I'll solder temporary extensions and go for broke. (I'm the cautious type)

Thanks!

Scott Seickel said:

The cover should come right off when the wires go in.

You may need to be creative to get the wires back out.  I would just solder another small piece of wire end to end to enable you to pull the grid wire back out. 

[Norman S Braithwaite]

Sometimes the coil shield cans can be very stubborn, especially if there is some corrosion or flexing of the shield base.  The shields were made to such tight tolerances that they must be removed straight up.  Any tilting will cause the shield to bind.  However, in some cases I have found that the only way to remove some shields consisted of rocking back and forth, left and right, perhaps until enough surface corrosion has been scraped loose.  I have also had some luck with rotating stubborn shield cans in order to remove them (poke the grid lead into the shield first).  As a last resort on some poor condition chassis I have had to pry the shield can off the base.  A lot of force is required sometimes.  This is likely to damage the bottom of the shield can, however, so I only resort to prying if the shield can is in poor condition.

Norman

[Ken Carr]

Thanks, Norman. I will persist until I free them. At least I know now that I am not fighting a rivet or such.
I may spread a little bar soap and work it in.

[Ken Carr]

I finally got back to the radio and was able to remove the IF shield can. It took plenty of rocking and twisting along with several applications of liquid soap. I will buff all contact points so this won't happen again.

[Angelo]

How far down you push the covers will affect the performance of the radio..Some where  in the alignment  of the radio it tells you that make sure you have good clean metal on the can to the base..Just a FYI.

[Ken Carr]

Thanks, Angelo. I have two of them off so far. After removing them I polish the inside and the rim of the base so they will go together more easily. This is the first time in 75 years that they have been removed (my best guess). The last one took me about 40 minutes of effort to get it off.

I will find that section of the alignment instructions. It seems there are a lot of critical components in this radio!

Angelo said:

How far down you push the covers will affect the performance of the radio..Some where  in the alignment  of the radio it tells you that make sure you have good clean metal on the can to the base..Just a FYI.