These two young ladies show how easy it is to build a Hex Beam from RadioWayvz. (Above)
The Boy Scouts are on the air for more than just the annual JOTA Event. They have special events year round check the K2BSA website.
Below, you will find an easy and fun project to build.
I have spoken with Bob Heil K(EID and received permission to
direct link to his Pine Board Project, to build a working AM transmitter from a few parts all on a piece of WOOD!!
The Pine Board Project
We call this the Pine Board Project for a reason and that’s because we will actually be building a transmitter on a pine board, so you can see the circuitry. We want to try to not only build things, but we want to teach you what you’re doing when you are building it. You won’t just learn soldering. In this first project you will build a simple field strength meter, but that’s just the beginning. You will also build a 300 volt power supply, a microphone preamplifier, a transmitter, and a final tuner. Once all of that is done we will put it all together. The goal is to try to help you learn a little bit more about the schematics and how to build all while having fun.
*Special thanks to W4IQN for the graphics!
Caution: This is a fun project for all ages, but kids should be doing this with adult supervision due to the danger of high voltage.
Project 1: Field Strength Meter
From HAMNation episode 289.
Parts and tools:
A pine board about 6 x 6 in.
Rosin core solder
Terminal strips (4s or 5s are best)
50k Potentiometer (a pot)
Meter 100 micro Amp
RF Choke 2.5mH
Antenna 19 inch piece of solid wire (coat hanger works fine)
Having trouble finding the parts? Check out these sites.
http://vacuumtubes.com/ (best tube supplier)
Mount terminal strips on the pine board close, but not touching.
Every diode is polarized and as you reference the pictorial or the schematic you will see that band on the diode has to be placed in a very specific position with the band toward the plus side before soldering
Solder the choke into the terminal strips.
Solder the potentiometer from the choke/bottom terminal strip to the upper right side of the terminal strip.
Now it’s time to solder on the Meter. Solder the green wire to the upper right side of the terminal strip attached to the potentiometer and the red wire to the upper left side of the terminal strip attached to the diode. (picture)
Don’t forget to put your knob on your pot and attach an antenna. (picture)
The finished Field Strength Meter should look like this and now you’re ready to test it!
If you’re new to Ham Radio you might be thinking, “What the heck is Bob talking about (aka vocabulary terms)???” We’ve got you covered!
Potentiometer – (or a pot) is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider.
Capacitor – a device for accumulating and holding a charge of electricity, consisting of two equally charged conducting surfaces having opposite signs and separated by a dielectric.
Diode – a device, as a two-element electron tube or a semiconductor, through which current can pass freely in only one direction.
Project 2: Power Supply
From HAMNation episodes 290, 291, 292, 293, 294, and 295
Parts and Tools:
3- electrolytic capacitor 20 mfd@ 450 v
2- 1k ohm 2 watt resistor
6X5 vacuum tube
Ceramic octal socket
2- solder-type terminal strips – 6 lug
3 lug barrier terminal strip
Pilot light socket
Pilot bulb (6.3v)
AC power cord w/plug
Wiring before transformer and tube socket.
Project 3: Microphone Pre-Amp
We haven’t actually started this portion of the project on HAMNation yet, but for those that like to work ahead here is the parts list and the schematic.
Parts and Tools:
Tube socket (9 pin miniature)
4- Solder-type (6 lug) terminal strip (trim length as necessary
barrier -type (3 lug) terminal strip
Electrolytic capacitor 10mfd/ @450v
Electrolytic capacitor 10mfd/ @25v
2- Ceramic disc capacitor 0.001 mfd
Ceramic disc capacitor 0.02 mfd
Ceramic disc capacitor 0.047 mfd
Resistor 1k Ω
Resistor 33k Ω
2- Resistor 100k Ω
Resistor 1M Ω
Variable resistor 50k Ω
Knob for above
2- ¼” phone jack
Project 4: Transmitter
To be continued…