This is what I transcribed from your "schematic":

You have a delayed on circuit. D1 isn't required and R2 can be omitted (leave discharge unconnected). Still would like to know what type of LED you're using that you don't need a current limiting resistor.

Now, I'm trying to solve for powering off the radio when the vehicle accessory circuit becomes un-powered. Searching this site and others, I've come across two options: Depletion mode FETs and J-FETs.

What does the circuit above really drive? What does it take to turn the radio off manually?

EDIT: went back and re-read the first post. What are you using for the press to turn on the radio? What is it doing when the "press for on" lasts a long time? What happens if you press, presumably the same button, to turn off the radio for a long time?

Depletion mode MOSFETs aren't common.

Cheapest I've found is a pack of 20 on Amazon for $10 USD, but not sure if they will work or not.

I wouldn't buy any MOSFETs or JFETs from Amazon. It'll probably be fake stuff from China. If you want to buy from China, you'll find lower prices on AliExpress. Same parts with less markup. Same problem with them being counterfeits or rejects, so be prepared to test some or all of them.

 

Hello,

I'm new to the electronics field. I've been doing simple projects on bread boards and have a very basic understanding of very basic parts and concepts. However, I don't know what I don't know, and just needing pointed in the right direction really. I'm not asking for answers, just direction. I would prefer to discover the solution myself so that I can really learn it.

What I'm wanting to do is create a circuit that will power on my amateur radio for me when my car turns on, and turn it off when my car turns off.

I know I need to tap into certain wires that will become hot when the ignition is turned on so that the circuit can sense that the car is on. And, to turn on my radio, I know I need to tap into the switch under the power button. This power button on the radio needs pressed for about a second for the radio to turn on, and pressed for about a second for the radio to turn off.

What kind of research terms should I be researching? What are circuits like this called? Is this even possible without an IC or Arduino/computer?

Help is very appreciated. Thank you.

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3

You'll be glad you got the book.

 

@dl324 Yes, the book uses the dots on the IC. On the breadboard I do have a resistor in series with the LED. But, will be using a relay for final circuit. Does a relay need a resistor?

When I press and hold the power button when the radio is off, and keep holding it down, the radio just turns on and stays on. Tested this for 60 seconds.

When I press and hold the power button when the radio is on, and keep holding it down, it just turns off and stays off. Tested for 60 seconds.

I think I see where you're going with this... and I like it.

 

I wouldn't buy any MOSFETs or JFETs from Amazon. It'll probably be fake stuff from China.

Don’t know why my experience is so different than yours. I have never received a fake component. I cannot imagine how anyone could make money selling fake components, except in the special case of obsolete, unobtainable ones that sell for 10s of dollars. Perhaps it is because I never buy obsolete components.

 

I've ordered these.

https://www.amazon.com/gp/product/B07FMKT5GX
https://www.amazon.com/gp/product/B083TJW4JN

I've also been thinking about how to keep the radio in-sync with the car. For example, if the radio were to be manually turned off and left off, I don't want the car turning off to turn it on. On the radio mic-out cable, there's some wires that supply positive voltage when the radio is on. I think I can use these with depletion mode FETs or J-FETs to achieve the radio state being in-sync with the car state.

This screenshot is from the FT2900R manual. the two middle pins are ground and +8v that goes high when the radio is on.