Synchronous AM detector mod of a Sony SRF42 AM stereo walkman (links to my web page about this). This may be too specific and assumes you can find a Sony SRF42. But synchronous AM detection does sound good on weak stations as long as the sync can get a lock on it.

Great idea. I'll have a look at it!

The sound system in my '08 IS250 seems to have a very sophisticated AM receiver. You can drive just about anywhere in the state and still pick up 702 AM (50kW, just south of Liverpool) in the daytime. It seems to be doing some DSP-like work when power line noise would otherwise render the signal unreadable.

I might try to find a circuit for it when I have some spare time haha...

An idea I've had for a while for better AM reception involves separating out the upper and lower sidebands and, using DSP, sample each of them.. Only output what is the same in both sidebands. Use the carrier to derive the sampling clock.

I wish we still had AM-stereo. Did Delco ever make AM stereo car radios?

At the time Australian cars were being fitted with stereo AM receivers, Holden was using Eurovox rather than the GM-aligned AC Delco.

That's surprising that GMH didn't use Delco as GM makes these "in house" (assembled in Mexico) for what must be a very low price. They were reportedly used by Rolls (with Delco name removed no doubt.) Apparently they did make an AM stereo model, the UX1, but would be hard to find now as junkyard I go to does not have many early 90's vehicles.

Video of a UX1 https://www.youtube.com/watch?v=F-nyEtV-j9A

(note AM-St button)

I think Holden always used other brands. They started out with Astor, under the Air Chief, brand, then moved to Philips with transistorisation, then to Eurovox then to Blaupunkt (which I have in my VY Commodore) and the Americans who own a last generation Pontiac GTO (based on the VT-VZ Commodore) would also have. I am not sure what they are putting in the German-built ZB model.