This GPS receiver module kit includes an extremely sensitive patch antenna, with factory pre-soldered Mediatek chipset RF module. It has three onboard LEDs for visual status indication, 3.3V regulator and power supply filtering, and 5V logic level conversion. It’s easy to build and directly compatible with all QRP Labs kits.
The RF module uses the MediaTek chipset and it is essentially comparable to the QRP Labs supplied <a href=”https://www.qrp-labs.com/skm61″ target=”_blank”>SKM61 GPS</a> module. The board size is relatively large (91 x 64mm), this is to provide additional patch antenna gain. Most GPS receiver modules with built-in patch antenna are a compromise between small physical size and sensitivity. If we drop the size constraint, it appears that the antenna sensitivity is optimum with a large patch antenna (25 x 25 x 4mm size is the largest available) and a large 6 x 6 cm PCB ground plane. According to the antenna datasheet the gain is 7.5dBic over that of a 30 x 30mm ground plane. Most small GPS modules are of course smaller than 30 x 30mm. </p><p>The board also includes supply filtering, 3.3V voltage regulator, and level converters to provide 5V input/outputs. The connectors are 0.1-inch pitch so they are easy to solder to. The 4-way connector pads section can be connected DIRECTLY to the <a href=”https://www.qrp-labs.com/ultimate3″ target=”_blank”>Ultimate 3/3S QRSS/WSPR TX kit</a>, with no pullups or decoupling capacitors. There are three 3mm LEDs on board, that give a visual indication of what is happening. They are:</p><p>Red: Power (always on)<br />Yellow: Serial data (flashes when the serial data burst is active)<br />Green: 1pps (flashes on for 0.1s once per second, when the 1pps signal is present)</p><p><strong>Advantages</strong> of this module, compared to the <a href=”https://www.qrp-labs.com/skm61″ target=”_blank”>SKM61</a> (and other comparable small GPS receiver modules), are:</p><p>1) higher sensitivity of built-in patch antenna, due to large ground plane<br />2) Provices facility for SMA connector and components for external active antenna if you prefer<br />3) Has onboard power / data / 1pps LEDs for an immediate visual indication of what is going on<br />4) Proper level conversion for use with 5V systems, not just pull-up resistors like on the <a href=”https://www.qrp-labs.com/skm61″ target=”_blank”>SKM61</a><br />5) Larger connection pads with 0.1-inch pitch, suitable for easy wire soldering or pin headers<br />6) Voltage regulation and all components already on-board, no need for anything other than wire, for <a href=”https://www.qrp-labs.com/ultimate3″ target=”_blank”>U3</a> connection<br />7) Low cost<br />8) A kit – fun and educational to build!</p><p>The kit contains the PCB with pre-soldered Mediatek chipset RF module, and all other through-hole leaded components for easy assembly. It also includes four nylon 12mm M3 hex spacers and four M3 screws, for mounting the PCB in an enclosure. The kit is supplied with a 25 x 25 x 4mm custom-manufactured tuned patch antenna. This is installed on the opposite side of the board to the other components. An SMA connector (not supplied) may be fitted if you prefer to use an external active antenna. A 3V rechargeable battery is included, which backs up ephermeris data and can ensure faster satellite lock after short-term loss of power. </p>