Short Circuits

I saw these Jaycar (an Australian electronics seller) electronics books for beginners mentioned on the GQRP list (page down to the bottom):

https://www.jaycar.com.au/short-circuits

The idea is relatively simple and fun circuits that are easy to construct and understand.  The first volume has discrete circuits assembled on a solderless setup.  The later books have solder projects with circuit boards and parts kits sold by Jaycar.  For example this FM radio caught my eye:

But then I looked for the TDA7000 and found that while it could be found on Ebay it is discontinued.  The prices on the TDA7000 chips that are available are high, probably would be cheaper to just get an old FM radio that used the TDA7000 ?  Here is a really interesting blog post on the TDA7000:

https://www.righto.com/2025/08/reverse-engineering-analog-TDA7000.html

BTW the blogger, Ken Shirriff, is one of the cast of the Curious Marc videos on Youtube !  Here is his traced out schematic for the TDA7000:

https://static.righto.com/images/tda7000/schematic2.pdf

Quite a complicated circuit although as he explains, a lot of the circuitry is there because the IC process favors some types of circuits over others.  It's easy to cut down on the active semiconductors when discrete transistors and diodes are used with actual capacitors, resistors and inductors rather than semiconductor equivalents.  The TDA7000 was quite popular with hobbyists at least partially because it was available from Radio Shack:

.

Here is the inflated price (this makes the Ebay prices more palatable ?):

The IEEE had an article about the TDA7000 in their Chip Hall of Fame in Spectrum:

https://spectrum.ieee.org/chip-hall-of-fame-philips-tda7000-fm-receiver

I will take a look at some of the other circuits in the Shorts volumes in future blog posts.

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm