Price - Stock No 300 - Happy Birthday 

Price - Stock No 301 - Jingle Bells 

Listen to audio for Happy Birthday  and Jingle Bells 



1. Check your P.C.Board carefully for damage to the tracks. A Circuit Tester or a multimeter will help check that there are no broken tracks.

2. Bend the legs of the resistor with long-nose pliers to match its holes and push it into place against the surface of the board. Remember that the drawing is looking at the PLAIN side with the tracks away from you. When in place, bend the legs sideways a bit to stop the resistors from falling out.   Solder in place - see Soldering Technique

3 There are 5 PCB pins.  Insert as per diagram and solder in place.

4. Identify the BC548 by the markings on the flat.  Ensure correct orientation and solder.

5. Insert the HK66T in the correct orientation.  To reduce the possibility of damage to this component, it is recommended that a heatsink tool (or pair of long nose pliers) be used to protect from excessive heat while soldering.

6. Insert the trimpot and solder in place.

7. Solder the positive and negative leads of the battery holder to their respective pins.

8.  Figure 8 wire is included to attach the speaker and switch away from the PCB.  The switch can be mounted directly on the PCB if you choose.  Cut the wire to appropriate lengths.  Strip the ends of the wire and tin the bare ends - see Tinning wire .

9. Solder the switch to its appropriate PCB pins.

10. The speaker has a positive and negative terminals.  Use the stripe on the wire to ensure the correct terminals are connected to the correct PCB pins.

11.  Rotate the trimpot so that it is set  about half way.

12.  Install batteries and turn on.  Adjust the volume with the trimpot.


Trouble shooting

Troubleshooting  if necessary will involve careful checking of locations and polarity of components. Re-solder all joints and check to make  sure  you  have  not  bridged across  between  any  two adjacent component legs.  The end  of  a  broken  hacksaw  blade  sharpened  on  an  emery wheel is a good tool for cleaning between soldered joints.

Technology Notes

The heart of this kit is the HK66T which is a purpose made Integrated Circuit for melody generation.  The output of this IC is fed to the Base of the BC548 via the 1K resistor and the 10K trimpot allows for volume control.  The BC548 amplifies the sound for output by the speaker. See - Transistors  

View the HK66T Datasheet

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