I reparied an old VFO for a friend. In it was a 10 K 7 watt resistor.
It is about the size of a USB memory stick and looks likeit was dipped
in a mix of sand like the mortor used for bricks.

I saw an artical where someone else had the same problem with that
resistor.

Are they just wire wound or something special, like a fuse resistor ? I
have seen just a few of them, but never checked them out.