Re: [ScoutRadio] KX5BSA
- 1) "straight" key
This one is almost too simple to believe, and yet is fun to build and
looks way more cool than you would at first suppose.
To make it even cheaper, I replaced the knob by cutting a dowel into
It ends up flat on top instead of round, but looks/works the same.
I pre-drill the blocks so the screws go in easy.
That way even the youngest Cubscout can put it together.
2) side tone generator
Find a supply of cheap piezoelectric buzzers and hook them to 9v batteries.
Mount it all on a board (or the same board as the straight-key).
You can buy 9v battery clips for a quarter, even at Radio Shack.
Shop around for 9 or 10 cents each.
You can get them for free by disassembling old batteries.
If you go this route, solder on the leads before hand.
It takes a fair bit of heat and the scouts will likely melt the
plastic before the solder sticks.
Everybody changes 9v batteries out of smoke alarms every six months, right?
I save the used ones. They have plenty of charge for this application.
Wala! an infinite supply of still-operational batteries (and clips)
Talking about the 9v batteries reminds me of another fun-and-easy project.
There's lots of other web pages that describe mostly the same thing with
small variations. Use one of the many online resistor calculators for
this application. My two favorites are:
I took one of these with me on a five day backpacking trip up the back
side of Mount Whitney this summer. Even if you leave it plugged in
overnight, it still emits enough light to get you through the trip.
-Mark Z, AF6AX
> Do you have instructions/schematics for the simple side-tone generator and straight keys that you have used in the past?
- A few years ago I was the "engineer" on a project sponsored by our
company's amateur radio club to build code practice oscillators. What
I came up with was a 555 circuit driving a piezo "speaker". The key
was a strip of aluminm bar stock with a knob from a half a wooden spool
and a poker chip, mounted on top of a baseball collector card box which
served to contain the electronics and battery. The total build was
either 36 or 50 units for a little more than $2 each ( exclusive of the
9V batteries which were supplied outside my work ). The clear plastic
box allowed us to include out club logo.
The 555 circuit that was the basis for the code practice oscillator was
derived from a circuit that I had used to control a laser pointer in a
light communication project, so the sound output of the CPO had the
same square wave quality that my light beam project did.
Depending on the skill level of your group, and of course your budget,
you could do some very interesting things. It is very simple to
substitute a bright LED for the speaker. Now you have a transmitter at
a few hundred Tera-Hertz ( no license required ). It can be received
by eye, or use a photo detector with an amplifier. Use some curved
mirrors or lenses to demonstrate antenna gain versus beam width.
It is a small step to go from modulating an LED with Morse Code to
voice amplitude modulation, but you lose the ability to "copy by eye".
But the photo detector with amplifier works nicely.
Rather than use voice, set up stations across the camp with PSK31.
I doubt there is time to do it this year, but but a group of scouts
with a little leadership and help could build a system equivalent to
what set the light communication voice distance record of 173 miles.
If you sparked enough interest they could be testing it next Summer and
put on a fine demonstration by JOTA 2009.
If light communication is not your thing, a little bit of electronics
could produce a two inch diameter speaker wired to "talk" by sending
out PSK31 audio and "listen" by receiving them. Mount that two inch
diameter speaker at the focus of parabolic reflector ( made by some
Scouts out of paper machet ). Sending text messages by sound waves for
several hundred, maybe a few thousand, feet does not match talking to
Europe on the radio. But it does teach electronics. It is well within
the skills of the Scouts. Doesn't require a license. Might be fun.
--- In ScoutRadio@yahoogroups.com, "ab5eb" <ab5ebdxer@...> wrote:
> What ideas do you guys have for the scouts outside of the radio
> station itself?
- InfoAge in Wall Township, New Jersey is considering making the Diana
Site on the banks of the Shark River available for low-impact overnight
camping. The Diana site is the home of the Ocean-Monmouth Amateur Radio
Club, N2MO, and the InfoAge Museum.
If your troop is interested in a bit of Radio Scouting, along with a
visit to the InfoAge museum <http://www.infoage.org>, please reply to
Link to Site photographs: