Kenwood TH-D74

We first met — I think — in the summer of 2015 during the Hamfest in Friedrichshafen. At that time I had a mobile Kenwood transceiver TM-D710 which was quite nice by its own. However, after several months using the TM-D710 I got increasingly annoyed by some of its shortcomings, most of them purely subjective (but I also had some objective complaints to do). Thus I borrowed it to my friends at YO5KUC ham radio club, indefinitely, to use it for their weekly QTC bulletin because they did not have a decent VHF/UHF transceiver.

Back to the TH-D74. As I was visiting Kenwood’s booth, I noticed this new portable transceiver placed under a protective glass shield and I asked whether I might play a bit with it. What was funny was that it had no product name or whatever written on it so I suspected it was a prototype.

Kenwood TH-D74, Friedrichshafen 2016. Notice that there was no product name or ID.

The guy there was not very happy with my request but he handed me the device, displaying a nauseous “whatever” expression on his dumb face (by the way, Kenwood, you really have to do better in this area: train your personnel to be nicer with your potential customers; take Icom’s example). But the new D74 was impressive in each and every single aspect: nice color display, excellent resolution, GPS included, APRS capable and — what was quite rare for any portable transceiver at that time (if not absent for all of them in general), TH-D74 was provided with bluetooth and USB connectivity. A huge plus !

To understand why is this (BT and USB) so important for me, you have to know that I really love to tweak things and create software that provide some additional functionalities beyond what a particular device provides out of the box. Usually this means that I have to get my hands dirty with low-level programming but this is such a fucking fun that I am kind of addicted to it. Imagine: to decode, discover protocols, sniff, investigate packets and create a piece of software without any help from the vendor. Sex on a stick ! So I need to know if a device is capable of some type of serial communication wirelessly and, indeed, TH-D74 is able to do so:

TH-D74 BT Device Information in Apple’s Bluetooth Explorer app. See Serial Port is listed as supported profile. For bluetooth profile description, see here.

So the adventure begins. I have big plans for this transceiver. First, I need to understand how can I properly communicate with it via BT. I prefer BT because I would like to keep it somewhere with access to satellites for GPS and for proper functioning of APRS and that means that will be at some distance from my computer. I need to get back to the trusty XCode and revisit my C skills (quite rusty these days) and dive into some coding fun. Hopefully, eventually I will be able to provide something useful and functional.

Some photos below taken when I received the transceiver. More to come.