Ensemble RXTX build – TX mixer

The TX mixer section doesn’t have quite as many components as the previous section, but there are a few band specific components including a toroid and transformer so you’ll want to make sure you have the right band selected if you’re following the WB5RVZ build instructions.

Like the RF mixer stage, the only SMD components are the FST3253 IC and three accompanying capacitors.

Ensemble RXTX TX mixer
Ensemble RXTX TX mixer

The through hole components consist of a 3904 transistor and a few capacitors and resistors. Watch out for accidental solder bridges between the closely spaced holes of the transistor.

Both the L1 inductor and T2 transformer have a lot of turns to wind onto a relatively small T30 core. If you have some 28 or 30 gauge magnet wire that’s a different colour than what comes in the kit, use it for either the primary or secondary winding on T2. That will help make it easier to separate out the T2 wires before soldering onto the board.

Ensemble RXTX TX mixer toroids
Ensemble RXTX TX mixer toroids

Here’s the top and bottom of the board so far.

Ensemble RXTX Top
Ensemble RXTX Top
Ensemble RXTX bottom
Ensemble RXTX bottom

One more section left in the build: the driver/PA section.