(continued)

Non-aviation headsets, such as the Maxon or MFJ typically do not
enclose the earphone in a muff. There's usually a bit of foam to
keep the thing from boring a hole in your head but it merely presses
against your ear. An ear muff, on the other hand, fits OVER your ear,
surrounding it with a plastic enclosure. In effect, an ear muff puts
your ear in its own private room - - hopefully, a quieter one. The
edges of the muff are padded - - some better than others - - and the
earphone is glued, screwed or wedged into the enclosure, positioned so
as to whisper sweet nothings into your shell-like ear. Or ears, on the
good headsets.

A good example of the ear muff type enclosure may be found on any pair
of industrial ear protectors, such as those sold by Harbor Freight.

http://www.harborfreight.com/cpi/cta...emnumber=43768

For about four bucks (less, when on sale), you'll get a ear muffs
that do a fairly good job blocking low-frequency noise, such as that
produced by a four-cylinder aircraft engine. The down-side is that
such ear muffs do little to attenuate high-frequency noise or
high-intensity noise such as that produced by a jet engine or a
firearm. But if you're Flying On The Cheap, especially behind a
Volkswagen engine, the inexpensive HF ear muffs work just fine.

Now the problem is how to get the earphone of your Maxon or MFJ headset
INSIDE the cup of the HF ear muff. One way to do this is to simply
dismantle the HF ear muffs, cut away a portion of the plastic enclosure
so that the earphone ends up inside - - with the boom mike still
OUTSIDE - - then glue things back together, trimming as required. If
you want two earphones you'll have to glue one into the opposite
enclosure then figure out how to get the wires from one side to the
other without making a mess. (Hint: Find yourself some large-diameter
heat-shrink tubing. Run the wire along the head band then capture it
in place with the heat-shrink.)

This sounds pretty crude but it DOES work. How WELL it works - - and
for how long - - is different subject :-)

Those large, padded stereo headphones (such as...


http://www.allelectronics.com/cgi-bi...ADPHONES_.html
)

....make pretty good ear muffs and have the advantage of coming with the
earphones already wired. If the impedance of the earphones happen to
match your radio, all you need do is mount the boom-mike to the outside
of one of the enclosures and replace the headphone lead with the lead
on the MFJ or Maxon headset.

If you're an ET-type bench-tech with lots of SMT repair experience
(...like me :-) soldering the miniature coax found in such headsets
will be no problem. Other folks may find it a bit of a chore largely
because tiny solder joints call for a tiny soldering iron, fine-gauge
solder, a magnifying hood and bright, well focused light. Otherwise,
it's a piecea cake :-)

(Need a teeny-tiny soldering iron? Try wrapping some #10 solid copper
wire around the tip of a regular 30W iron, allowing it to extend for an
inch or so. File the end of the wire into the shape needed for the
particular job, slather on a thick layer of high-quality non-corrosive
flux and tin the thing. A copper tip doesn't last very long but it
will survive long enough to do the leads of a headset.)

(more to come)

-R.S.Hoover