TH-D72A/E - N3UJJ

1 DEVELOPMENT CONCEPTFollowing is the designing and development concept for TH-D72A/E.• A genuine tool for communications via voice and data that is based on the TH-D7A/E.• An out-of-the-box transceiver with an internal GPS unit (turn-key solution)• Equipped with a USB interface• Emphasis on ease of operation (with multifunction keys; keys may not be minimized.)• Full-size dot matrix LCD display that enhances visibility for the user• User-updateable firmware• Large-capacity lithium ion battery• Compatibility with APRS inherited from the TM-D710A/EIn order to understand customer requirements, we did surveys at various ham shows, such as theDayton Hamvention, ARRL and TAPR Digital Communications Conference (DCC), JARL Ham Fair(Japan), Ham Radio in Friedrichshafen (Germany), etc.The many ideas gathered coalesced into the above development concept as the Product Planningstaff and Development staff virtually merged during the conception phase to come up with thepresent development program.1.1 GPS UnitWhen we developed TH-D7A/E series in 1997, it was difficult to incorporate an internal GPS unit in ahandheld transceiver. This was because, at that time, the GPS antenna and receive module weretoo large. The advancement of technology has enabled the miniaturization of these components andtoday they are mounted in a wide array of a mobile device such as a cellular phone, a GPS loggerand a digital camera, and is almost taken for granted.If an external GPS unit was required for a successor to TH-D7A/E, i.e. a handheld transceiver, itwould have been very cumbersome for a user to carry around more than one device as well asmultiple batteries and cables connecting them. Therefore, we started the development of theTH-D72A/E with the concept of an out-of-the-box product that delivers higher user convenience andwith the basic premise of incorporating an internal GPS unit.The internal GPS unit consists of a GPS receive module and a GPS antenna. After repeateddiscussions, to ensure enough GPS receive sensitivity and reliability, we have finally adopted a GPSunit that integrates a receive module using a SiRFstar III chipset, which is highly accepted in themarket, and a microstrip patch antenna. Also, we have separated the transceiver circuit and the GPSunit with an aluminum die cast frame to prevent mutual interference.During the development, we have conducted endless sessions of testing and experiment to comparethe performance of the product in actual operational applications such as ease of transportation andof mobile operation with competing products or GPS receivers on the market. Consequently, the newtransceiver ensures good positioning performance and satisfactory operation.Although TH-D72A/E comes with an internal GPS unit, your GPS receiver can be connected asbefore.TH-D72A/E CONTENTS 1From The N3UJJ.COM Document Library