v1.3 SMT Board - alanbjohnston/CubeSatSim GitHub Wiki

These steps are to install the components that are normally SMT (Surface Mount Technology).

The PCB has components on both sides. The top of the PCB is on the left in this photo with the AMSAT logo. The bottom is on the right.

The silkscreen outline markings indicating which side to mount the parts.

Before any components are soldered onto the board, the Surface Mount Technology (SMT) components should be installed, if they aren't already soldered on. C1, C2, and L1 make up the Low Pass Filter (LPF). The purpose of the LPF is to filter out all the undesirable radio frequency (RF) emissions besides the ones at 434.9 MHz UHF (i.e, harmonics, sub-harmonics, and spurs). J2 is the USB-C charging connector, which also has resistors R14 and R15 to set the current limit. The resistor R2 allows the software to detect the presence of the LPF and allow radio transmissions.

The minimum SMT is just the FM Transceiver module and the two LPFs as shown here:

If your PCB does not have a USB-C connector, then the Sparkfun USB-C breakout board needs to be installed, along with two 1k resistors.

Insert the 1x6 pin header on the bottom of the PCB. The long pins go through the PCB to the top side:

Then solder the pins on the top of the PCB:

Flip the PCB and install the USB-C board on the bottom of the PCB on the pins:

Here's how it looks from the edge of the board - top is up in this photo:

The pins sticking up on the top can be cut off with side cutters.

Next, install the two 1k resistors. Bend one lead over as they will be mounted vertically. It doesn't matter which side of resistors you bend - there is no polarity.

Insert the two resistors on the top of the PCB:

Flip the PCB over and bend the leads so the resistors are held in place:

Solder one pin on each resistor then flip the board over and verify they are fully inserted and straight, then solder the other pin.

The excess leads can be trimmed with the side cutters:

Here's how the look close up:

The board is now ready to continue the STEM Payload Board Part 1