If you can hear conversation and the radio, You should hear a piezo buzzer.
They come in several "loudnesses" and some can be wired for intermittant
tone. Intermittant tone can be more attention getting than a steady tone.
They are very inexpensive---wire one up to a battery, and take it for a test
drive in a car, windows down, radio up, at highway speed. LED on the panel
is great idea too. The LEDs come in several sizes and brightnesses. Be sure
to get the kind with built in resistor.

Scanning is good, but is not fail-safe. We all know how to scan--segments,
and near-to-far exam of the airspace. Do we always do it? We all know that
answer. In some Eastern soaring conditions, visibility in certain directions
and conditions can be limited, though the general visibility is well above
lega minima. (Up sun into haze, hilly background, etc). FLARM is partial
help, PCAS is partial help. No answer is complete.

Instructing a lowtime student in the pattern is a special problem, requiring
extra vigilance. Sitting in backseat, opaque globe in front of you, canopy
distortion maximised, teaching, correcting mistakes of student after the
error is obvious to him/her, but before it turns out badly. High workload
here with lots of distraction. High awareness of the problem helps.
--
Hartley Falbaum


"raulb" wrote in message
...
On Nov 19, 7:40 pm, fred wrote:
Since I can not hear most warning horns (old ears) I would like to
have a stick vibrator, ( maybe that is off the shelf) a big flashing
light or an explosion. My wallet hurts, and teaching USTALL doesn't
seem to work.

If you want a light, just hook up a panel mounted 12 volt LED
(available for a couple bucks at any electronics store) in parallel to
your horn. That way you have both a horn and a light.