AD9834 SMD Soldering

Soldering a small 20-Lead TSSOP IC might seem a difficult task, but by applying some very simple techniques, even the not so skillful amateur can have success.

The photo, taken using a small USB webcam in macro mode, shows a manually soldered AD9834  TSSOP SMD chip. This was achieved using the following procedure:

1. apply water based flux to the board
2. apply some solder to the tracks
3. remove excess solder with solder wick
4. align the IC
5. add some more flux
5. gentle touch each lead to re-flow the solder

PCB was done using the toner transfer method.

40m CW QRP Direct Conversion Transceiver

This 40m CW QRP transceiver started as an empty box. The idea was to build the box then try to fit a transceiver inside. Why? Because so many projects never get a proper enclosure, so this one started the other way around!

The schematic diagram is based on several ideas from the following sources: Forty-oner by SP5DDJ, W1FB QRP Design Notebook.

The enclosure was built using FR4 PCB cut using tin snips. Holes were drilled using a step drill, a very useful tool.

The final transistor, a 2N2219A, provides an output power of approx. 800mW @ 12V DC.

I hope this project will have a side effect ... learning to copy cw :)

FET Regenerative Receiver

This week I built a regenerative receiver. The schematic is based on W1FB QRP notebook and the construction ugly style, with all the components soldered in a PCB ground plane board. This was another exercise of going back to the basics, but, as always with the simple things, it was lots of fun.

The tuning is range is from 4 to 11Mhz. It was possible to ear some short wave stations. The frequency range was measured by inserting the frequency counter in the antenna input! Weird? No! When the FET is oscillating some energy is radiated by the antenna. This is a nasty side effect. Be very careful when listening, because you can also be interfering with a nearby listener.

The regeneration control is very sensitive. You must very careful adjusting it before the thing goes into oscillation. The maximum sensitivity point is just before the start of oscillation.

The audio amplifier is a LM386. The sound quality is good but the volume is somewhat low.