The Raspberry Pi 4 B is nice but requires more power than its predictors. The power connector on the Pi 4 is a USB-C. If you are operating in the shack and have a good power block this works well. Since all my portable equipment uses 12-13.8V Dc, extra equipment would be needed to power the Pi. To make power options more compatible for my needs, I like to power the Raspberry Pi through the pins on the 40 pin connector.
A good option for the power regulator is the LM338 from Texas Instruments. It is very similar to the LM317 but is capable of a sustained 5A draw and a surge of 7A. The output voltage is capable of 1.2-32V DC. A nice feature of this regulator is Thermal Overload Protection.
The setup of the LM338 is the same as the LM317. The 5k pot and 220 ohm resistor set the voltage of the regulator. After construction adjust the voltage to 5V using a good multi-meter. Once the voltage is set, connect the Raspberry to the 5V using pins 2 and 4. Connect pin 6 to ground. Make sure to use a nice size heat sink.
Links
https://km4nmp.com/2019/11/02/the-raspberry-pi-4/
https://km4nmp.com/2019/10/19/using-a-lm317-adjustable-regulator/
https://km4nmp.com/2019/05/11/lm7805-regulated-5-volts/
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