23 Oct 2021

Radio for Grandson

On Monday, we have one of our grandsons here. Whilst he is here, he wants to build a radio as part of his Design and Technology (DT) work. I have plumped for a TRF circuit based around the TD7642 IC, which is like the ZN414 of old.

Very many years ago I built two around a ZN414 for my boys. The plan is to build it myself first to prove it all works, then disassemble it so my grandson can build it after some soldering practise. In the past this circuit worked fine with a ferrite rod antenna.

I am finding things far harder now: my eyes are finding close work more problematic and my fine motor skills are poorer.

He wants to do a design brief and we can draw the schematic together. I can explain how it works in simple terms. Hopefully he can take it home.

No comments: