Small Engines (Lawn Mowers, etc.): String trimmer, centrifugal clutch, weed eater

Question
My inexpensive and almost 20 year old McCulloch string trimmer needs replacing, and I am looking for a new trimmer.  I like to trim with the engine running at low speed so the string lasts longer and the noise and vibration is less.  This works fine except when tougher weeds require more power.  About five year ago I bought a Ryobi trimmer to get interchangeable functions, and this unit apparently had a centrifugal clutch that requires more speed before the cutting head turns at all.  For this and other reasons, I sold the Ryobi and went back to the Mac.  Now I want to find a trimmer with the engine and cutting head ditect-connected without a clutch in between.  Most seeem to have the clutch.  Do you know of brands or models that are direct-connected?

Answer
I don't know of any direct drive models...usually the cheapest trimmers you find have direct drive but even nowadays those have a clutch.

You might try a low end Weed Eater or Homelite brand.  These were the last 2 companies I know of that had direct drive units.

Let me know what you find.
Eric