In the March 2006 issue of 'Sport Aviation,' back on page 130 is a
short article by Kathleen L. Witman that shows some examples of antique
avionics. But if you're interested in antiques most pilots need look
no further than their own headset.

See that quarter-inch phone plug? It dates from the 1880's. Such
plugs got their name from being used on telephone switchboards. Ditto
for that 7/32" mike plug, which was used by a competing switchboard
manufacturer.

The first earphones used in aviation were direct copies from the
telephones of the WWI era and were fitted with the telephone
company's plug. No mike of course; the first radios used Morse code,
set via a telegraph key strapped to the Observer's thigh. When they
finally got around to airborne radio-telephone sets they kept the same
earphones and again borrowed from existing telephone technology for
their carbon-type microphone, other than sticking a hunka broomstick on
the thing for a handle and using the smaller Stromberg-style phone
plug. That was so you wouldn't get the mike plug confused with the
phone plug, since the mike circuit was liable to carry enough current
to fry your ears if you got the plugs mixed up.

Carbon mikes and magnetic earphones remained in use into the 1950's
which begs the question, why are 'aviation headsets' still using
those antique plugs?

Modern radios continued to use different sized plugs for the mike and
earphones but they were now little things: eighth-inch (3.5mm) for the
phones and a skinny little 2.5mm plug for the mike. And that's the
plugs you get on any modern communications headset... unless you say
it's for AVIATION. That's when they dig under the bench, find the
box of antique phone plugs and solder a pair of Nineteenth Century
connectors to your Twenty-first Century headset.

Which don't match the plugs on your aviation radio anyway. To makem
match you gotta shell out another fifty bucks or so for an adapter,
which in many cases is nothing more than the opposite gender of the
antique phone plugs they soldered onto your headset on one end with the
pair of modern-day plugs THEY JUST CUT OFF soldered onto the other end.
And right about there you should be looking around for the hidden
camera, because this has to be the best joke since the talking mail
box.

Alas, it's no joke. In fact, when you think about it, it's more on
the order of a scam since some retailers charge as much as seventy
dollars for the patch-cord needed to adapt an aviation headset to an
aviation radio. Which begs another question: Why? Since you really
don't need those antique connectors any more than you need to spend a
buncha money for a headset simply because it sez 'AVIATION' on the
box.

If you're flying on the cheap you're probably using an inexpensive
hand-held radio. Odds are, your radio is made by Icom or Yaesu and
uses the standard 3.5mm/2.5mm plug configuration found on millions of
hand-held ham, industrial, police, marine and even CB radios. Becuase
for every aviation radio those companies sell, they probably sell a
hundred of the other kind. Given that aviation-band AM radios makes up
such a small part of the communications market (everyone else has gone
to FM) it should come as no surprise that the chassies and connectors
on aviation radios are usually identical to those found on ham and
commercial radios. And that means the inexpensive headsets for
NON-AVIATION radios usually work on your aviation-band hand-held. And
by inexpensive I'm talking less than ten bucks. Here, lemme give you
an example...

I'm writing this on 4 May 2006. I don't know when I'll get
around to posting it but for the past month or more, All Electronics (
http://www.allelectronics.com/ ) has offered a headset and matching
VOX/PTT unit that works with Icom and Yaesu radios.

(COMMUNICATIONS HEADSET W/ BOOM MIKE, CAT# HP-41 ($3.00)
VOX MODULE, MAXON, CAT# VOX-2 ($3.50) )

These are new-surplus items. As received, the internal 1.2v nicad cell
in the VOX unit will be discharged, making the VOX function inoperable,
but the manual PTT works just fine. (Down below I'll tell you how to
charge the nicad. With VOX (ie, Voice Operated Transmission) there's
no buttons to push; just shout 'Talk to me, Goose!' and the odds
are, someone will.)

If you go to the site above and look at the pictures you'll see that
the headset is a one-sided affair with just a single earphone. It is
an intelligently designed unit that fits an American-sized head but
folds up into a package that will fit in your shirt pocket. And while
it fits well enough, the foam muff on the earphone doesn't do much
good in a noisy environment, a factor of critical importance in the
cockpit of many airplanes and one I'll address in detail in a moment.

However many of these units All Electronics may have now, the odds are
they'll all be gone shortly after this is posted. While there's no
reason you can't make your own headset, a point I'll get to in a
minute, a lot of you aren't hams, don't pick your teeth with a
soldering iron and would rather buy your electronics rather than build.
In which case you might want to send MFJ Enterprises a thirty-dollar
bill and order one of their ham radio headsets.

http://www.mfjenterprises.com/produc...rodid=MFJ-288I

You'll have to tell them what radio you have; the catalog number
above (MFJ-288I) is for an Icom. What you'll get for your money is a
very well designed headset similar to the surplus unit from All
Electronics but wired with a neat little PTT switch you can clip to
your tie. Or the bib of your coveralls. Or whatever.

Here again, the one-eared ham-radio-style headset simply won't cut
the mustard in a noisy cockpit but down below I'll explain how you
can add your own ear-muffs and even a second earphone, too. But for
those of you who insist on buying a headset that works right out of the
box, I suggest you take a look at Warren Gregorie's AIR-680.

http://www.warrengregoire.com/aviation-headsets.htm

This is the most comfortable headset I've ever worn. It is of very
good quality and at about a hundred dollars, is inexpensive compared to
most other 'aviation' headsets. If your only option is to buy
solutions to your problems then this headset will satisfy your
'aviation' headset needs without breaking the bank. You'll have
to tell them what radio you have and what kind of plugs you want,
including the arrangement of antique plugs and patch cords, if desired.


(to be continued)

-R.S.Hoover