Price - Stock No 160
Check your kit
VOYAGER is a super-sensitive FM Radio microphone developed by Talking
Electronics. The components are all common types of resistors, capacitors
and transistors matched so well in this circuit that amazing
sensitivity and distance are obtained. The name VOYAGER was
given to it "because it goes so far". We have re-designed the Board
and further matched some components to suit the
needs of the classroom. The result is a superb bug which
is compact but powerful, and quite easy to build.
Check Your Kit
- Check the P.C.Board for damage, and check continuity of the
tracks with a multimeter or circuit tester.
- Identify the five resistors either by their colour bands or with a
multimeter - a Digital Meter will give a precise reading of the values
of the resistors. Mount them in their respective places. You will
have difficulty in trying to mount them
flat so bend the legs so the resistor leans upwards at an angle to the board,
preferably with the high end closer to the side of the board, and
leaning down towards the centre. Bend the legs sideways on the track side of
the board to stop them from falling out. They can be
soldered at any time.
- Identify the six capacitors by their numbers and mount them in
their correct places. They can be put in any way
round. Push them down close to the
board. This will improve the stability of your bug. The soldering
is extremely important for success - Refer Soldering Technique.
- The Trimmer Capacitor can be gently pushed into place and soldered off.
- Bend the middle leg of each transistor backwards a little to match the
holes and push the transistors into place. Once again push
them well down to the board.
- The three pins are to connect the microphone (2 pins) and the
aerial. The three holes are drilled out larger to take the pins. Push
them in and solder. Also apply a little solder to the end where the
wires connect to tin the pins. The Fig.8 wire has a wire with a white
trace. I usually use this as the Positive wire. Strip, tin
and solder the wires to the pins.
- Study the diagram of the microphone and solder the metal tag to the
Negative pole as shown. Solder the wires to the poles but make sure the
polarity is correct - black/white trace to Positive pole.
- Turn the board over and push the battery holder
into position down to the track side of the board. Check about
how far down you want it to go,
remembering that you need room to get the tip in to solder the legs to the
track. Lift the battery holder out and heat the
legs until you get solder to stick at about where the legs will
meet the board. Push the holder back into position and
solder into place.
- Take a piece of 3mm rod. Hold the winding wire from your
Kit and wind FIVE full turns so the two ends are both pointing
down. The windings should be separated
from each other by 1 to 2 mm so the ends about match the holes in the
board. Leave the coil on the former and nip off the ends
long enough to fit through the board. You will need to take a blade and
scrape the plastic/enamel coating off the ends of the coil so you can
solder it in place.
You are now ready to try the bug. Slip a 9V battery into
place, turn a FM radio on and move the station
selector across the dial to find the frequency that the voyager is
transmitting. If you cannot find a signal try spreading the
coils apart. This will increase
the frequency of the bug. Try again to find its
frequency. If it comes on top of an existing FM station
adjust the width of the coils. Final trimming can be done by
adjusting the trimmer capacitor.
The length of tinned wire is great as an aerial for tuning the bug and
you will find that it will transmit at least 30 Metres with this
setup. Adjust the receiver aerial to get the best reception. An
aerial wire up to 1.7 Metres will give a range of 200 Metres or more.
Troubleshooting consists of checking carefully
that all components are in their correct positions.
- Start from the beginning and check each component
- Check that the transistors have the flat on the
body TOWARDS the end where the microphone
- Look for the + and - on the board at the microphone connections and make
sure they are connected correctly.
- Check that the receiver is switched to FM mode, is
turned ON, and the aerial is extended and the volume turned up.
- Re-solder the joints on the battery holder legs.
- Look carefully at each soldered joint; re-solder any
- Extend the aerial wire upwards at right angles to the board.
Careful positioning of components and
good soldering technique should give success without any
difficulty. When you are operating the
bug, remember that fingers touching components or even near them will
alter the capacitance and affect the balance of the
A slide switch and leads are provided; you may choose not to use
it, but if you choose to use the switch, provision is made on
the positive rail. There are two
unused (and usually undrilled) donuts. Cut the track between the donuts
and connect the wires from the switch to each of the donuts.
Remember the switch is Double Throw Double Pole
(DPDT) so connect the wires to the centre and one end poles on the same side of
the switch. If you don,t use the switch so you will have to
remove the battery to switch off. The current drain is 4.6mA
so a 9V battery will last about
20 hours, or an alkaline type about 50 hours. The advantage of
the alkaline battery is that it will hold its voltage high for much longer
and its output does not fall off so quickly.
Contact CdS electronics