Kanga DX Direct Conversion 40m Receiver Kit – Stage 2: Audio Amplifier

I set about the same method of splitting out the pre-packed components into a bowl making selection and testing easier. The instructions again are quiet clear, with good values of the resistors and capacitors.

I did have to overcome a few mistakes, but whilst it was a ‘mistake’ for the board, its a good exercise for me in being able to correct issues, in this case the Mylar 100nF capacitor. The mistake I made was getting in confused with the smaller 104 labelled capacitors. I looked up a picture of a completed board, and can see that the ‘mylar’ (green) capicator was needed to be changed. Using some solder braid and solder sucker, I was able to cleanly correct the incorrect component.

So I had an email ping me that my recently re-aquatined friend Pablo was flying (in real time), and was able to watch the video of his flight and the real-time radio transmissions. It was utterly amazing as people responded to the flight requests ! It was good having some ‘chat’ banter as well.

I set about fitting the one IC at this stage, the LM380, a simple audio amplifier and the required molex heads to connect the loudspeaker and variable resistor, all which went on well using the ‘solder a little’ then push thru method to get them nicely aligned and snug to the board.

So by now it was abou (I think) an hour into the build and i re-checked my work, having had an issue on an IC holder on the frequncy counter, didnt want to repeat the same issue. I found that i was a little light on the solder, so add a tap more just to make sure the pin would have good conductivity. Pablo had given us a great filght over the Rocky Mountains and had landed his jet via his controls, with an massive to taxi to the gate !

So time had come to test, i hooked up the PCB to the mains adaptor on 12v and hey presto, a healtly static sound came out the speaker. I could use the variable resistor to control the volume, so everything was worknig perfectly !

I had a great time building so far, more so thanks to the relaxing flight and chat with Pablo. I headed off to relax a little more with some wine and cheese myself 🙂

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