The ZM-2 Emtech Antenna Tuning Unit

I ordered this kit from the USA to go with my YouKits HB-1B QRP CW Transceiver. It has a good reputation for tuning both unbalanced and balanced antennas and has appropriate connections for both. The ZM-2 can be built with either BNC or SO-239 sockets. I ordered mine with BNC, as these seem to be standard amongst QRP equipment. As a QRP tuner, it is limited to a maximum of 15 Watts throughput.

The ZM-2 has no inductance tuning. Just two polyvaricon capacitors, two toroids and a few other minor components. It is a basic but enjoyable kit to build, and most times it enables a 1:1 SWR to be achieved. Bands covered are 80m to 10m. If you’re not comfortable winding toroids, these are available pre-wound for a small additional cost.

My build photos follow to assist a potential builder. The photos start with the completed ATU. Click on any of the images and then scroll down to see them all. Photo 01 shows the front panel assembly. This front panel first requires the attachment of a self-adhesive decal (you get supplied with two as they can be tricky to fit with correct alignment) and then removing the decal from the component holes – best done with a half-round pointed needle file. This is then lacquered several times for protection. Then you fit the major components and connect up. Photos are in order and self-explanatory. I built mine over a couple of evenings.

Emtech has further details with current prices, plus both videos and build photos.

73

Mick M0GWD