How to remove a cracked ferrite slug?

[Damo666]

Like a prat, i've accidentally broken an iron dust core by turning it too much. It appears to be cracked in half and wont budge at all. Any ideas on how to remove it please? Cheers. Damian.

[vinrads]

Hi if the slug is the type with the hole through i have had success by gluing a match stick in the hole using aroldite type glue, or it is possible sometimes to remove the bottom slug to gain access to the underside of the damaged one,and hope it is not cracked all the way through, good luck ,regards Mick.

[Peter.N.]

You need to try and get all the loose bits and powder out first or they will jam it, turn it upside down if possible or blow it out with compressed air. You could try drilling it out very carfully, although this often ends in tears.

Peter

[Tazman1966]

I have successfully managed to use a very small drill to break up and remove the jammed core. Make sure you ge te angle right though or you'll end up drilling through the former like I once managed. In order to get the remaining bits of broken core out I blast some "Servisol" down the former too.

Good luck!

[Damo666]

Hi Peter, Mick, etc. I desoldered the IF can in the hope of getting the slug out of the bottom of it. This wasn't to be unfortunately. I ended up ripping a couple of pins out of the transformer in the process, rendering the thing useless. I've now thrown the radio in the junk bin for a spares donor. Thanks for all your help anyway guys. I must be more patient in future.

[Peter.N.]

Oh dear! Its always going to be a risky operation, I have done it myself a time or two, breaking through the side of the former is the usual problem - in the days that I did it, likely it would be a customers set.

Peter

[dominicbeesley]

I do this on a regular basis - I've yet to work out how not to break the XXXXing things! I've tried the proper plastic trimming tool things but they usually break off in the slot which is just as hopless

To replace them though I usually end up breaking them up and replacing them with a smaller slug and a rubber band if there isn't one to fit...

Dom

[XTC]

Can you get a purchase on it still or have you crumbled away the screwdriver slot?

If you can find a way to turn it, you need to lubricate it with earex or a drop of three in one. Give it time to soak in, preferably overnight and make sure that gravity helps. Then try turning the core both ways.

If it's completely stuck and the slot's gone, you'll have to drill it out ever so carefully, or use a burr on a Dremel to eat into it.

Pete.

[peter_scott]

For cores that have the hole right through them I've had success using a strip of brass that fits well in the slot. This can be pushed right through and
with a bit toing and froing it's usually possible to apply torque evenly to the fractured core and get it to unscrew.

The particular little brass strip that I'm referring to was in fact an adjuster and has a little plastic grip on one end. I can't remember where I got it from now but almost certainly from an old tele. I would think you could probably make one by trimming some sheet brass.

Peter

[Billy T]

There's no need to remove a broken slug, just put a drop of melted wax, glue or similar down to stabilise the broken bits, then depending on whether it is peaked too low in frequency or too high, screw another ferrite slug in to bring it down, or a brass screw to raise it up. If the caps are outside the can, you can also retune it by reducing the capacitance if too low or increasing it it too high. Or you could fit a new IF can from a junked set.

Better than condemning it to the junk pile because you wrecked the coil. Bit late now but it might save another set in the future.

I have a piece of plastic tube with a small diameter ferrite slug in one end and a brass screw in the other, it is a useful tool on these occasions and very quickly and easily lets you see which one peaks it.

Cheers

Billy