The first thing I always like to complete in a kit is a way to power it. The Survivor expects to be powered by a battery or supply that can furnish around 12 V and at least 2 amps. I like to use a 12-V gel cell battery for this purpose. Some parts of the Survivor circuit rely on a regulated 5-V supply, so there is a 5-V regulator circuit on the board. Let’s build that first. Make sure you read through the manual before starting to solder parts to the board. It’s good to be familiar with the entire build process before you start, and the manual contains helpful hints and reminders to keep you from making mistakes.
Now install the following parts:
- the DC power jack (near the back of the board, to the left of R1)
- D1 (make sure you observe the correct polarity)
- U6 (install so its orientation matches the outline on the board)
- C42 (again, make sure you observe the correct polarity)
That’s all the parts that make up the voltage regulation circuit. One other thing you’ll need is a way of shorting out the two pads labeled “on/off” (next to D1). That’ where the on/off switch connects to the board, and shorting the pads turns on the radio. I like to use 0.1″ headers and pins like these to make connections between the board and the controls and inputs, because it makes it much easier to temporarily connect jacks, switches, and pots to the board for testing while you’re building. If you decide to go that route, make sure and get a crimping tool to crimp the pins onto the wires.
So, this part of the circuit is quite simple. D1 acts as a reverse voltage protection for the voltage regulator (just in case your connect your battery backwards). The voltage regulator itself does exactly what its name implies–it takes 12 V input and outputs a regulated 5 V supply. C42 is there to filter out any AC component that might be present, further regulating the voltage. It’s pretty simple.
To test, plug your battery or power supply into the jack, short out the “on/off” pads, and use your multimeter to measure the voltage at the + pad for C4 (right next to D1). The voltage there should be the same as the voltage of your supply. Next, measure the voltage at pin 6 of U3 (near U6). This is where you should measure very close to 5 V. If your board passes those two tests, you’re good to go. Disconnect the battery and unshort the “on/off” pins and move on.
Next: The VFO