Sunday, 23 October 2016

Building the Ultimate 3S

Following on from the build of the Synth module yesterday, today ive done the majority of the construction of the QLG-1 GPS receiver module, and the Ultimate 3S Beacon transmitter itself,

First however, I had the faulty Clansman 10m Audio Extension to repair!

This was an absolute pig! The cores are tinsel wire, which gives the cable great flexibility, but makes repair really difficult. In order to rejoin the cores,I had to wire wrap them with solid tinned copper wire, but the size of the cable and the flexibility made it extremely hard to hold everything together while I did this, and then to solder it all together and sleeve the joins. But it is now repaired and tested as usable.

So, onto the Ultimate 3S. Building the QLG1 GPS module is remarkably simple, with very few leaded components to install. Unfortunately, my kit had two components missing. One, a 100nF dipped ceramic, I simply replaced with one from my own stock. But the other missing part is a 0.1uH axial inductor. I havent anything of this value nor even close to it. So ive had to drop the supplier a line asking for a replacement.

As the GPS module is not yet complete, I have deliberately not yet fitted the backup battery. It is just waiting on the inductor now and can then be powered and tested.

Building the 3S itself is a little more complex, as there are more parts to fit, and a higher density on the board, but still quite straightforward. The only thing that complicates it a bit is that the manual covers the controller build for three different projects, which leaves the builder to fathom out which links etc must be installed. I would have preferred the manual to have been more specific to the 3S build. But then again, theres still plenty of optional features in the 3S build to decide, such as whether to have software controlled LCD brightness (in my case yes), whether to soften the contrast control (yes), etc

The module can use its 5v supply to power the BS170 MOSFET PA stage, by adding a link, or the PA can be powered by a higher supply, for instance if fitting extra BS170s, without the link. As I want to use mine with the one installed transistor first and then add more later, and didnt fancy having to unsolder a wire link, ive been clever and fitted header pins and a removable link as used on PC motherboards. Ive also done this for the two links that hard wire the LPF module connections, as these links need to be removed if the relay switched band module is used, which I may wish to add later,

Im hoping alls well, but I wont be powering it up just yet. Im going to build one of the LPF modules first, so its all ready to test fully.

No comments: