My Swan 350 radio has tuning slugs in the VFO to handle different bands. The 10-meter band has a slug that wont come out, I may need to use a longer wrench but these old slugs break apart and crumble.

What can I do about the slugs and where can I get new ones and deal with the persnickety ones?

  • $\begingroup$ Hi Ben! I rewrote your title to be more generic and to be in the format of a question. I hope you don't mind! $\endgroup$
    – rclocher3
    Feb 7, 2022 at 18:56
  • $\begingroup$ Not an answer because I don't know, but there are antique radio forums that talk about this a little. There is some thought that heating up the wrench with a soldering iron might free gummed up slugs, but if it is good and stuck it might already be broken, and any turning is causing them to "cam" themselves tighter in their little inductive homes. $\endgroup$
    – user21417
    Feb 7, 2022 at 19:52

1 Answer 1


You should never use a metal tool on powdered iron or ferrite tuning slugs, adjustment tools for them are usually some type of plastic. You should be able to find these online. The better the fit, the better it will work.

Heating with something like a hair dryer might help loosen them. If the coil form is plastic or phenolic you might try a little bit of liquid lubricant, some coil forms are made of paper and may be damaged by it though.

Once the slugs are broken they will be very difficult to get out, you generally have to use something to break them up into smaller pieces to get them out.

We used to use a little bit of cornstarch to lubricate them.

As for a source of replacements, you'll just have to do some shopping. There are a lot of places out there selling vintage parts. You may have to buy some surplus coils with the same size form just to get the slugs.


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