The parts are easy to find in the plastic zipper bags and even the smaller ceramic capacitors can be identified from the values hand written on the paper tape they are supplied on. The parts are not ordered by circuit section but bagged by type (broadly...) like: capacitors, resistors, semiconductors, inductors & mechanical, ICs & sockets.
 
The two shiny areas are solder tin ridges
to assist with manual, slightly elvevated,
mounting of the 330-uH SMD potted inductors
Besides step-by-step and illustrated guidance, the µTracer Manual also has a fine selection of Tips & Tricks applicable to various components and assembly methods. I really liked the tip for mounting the four SMD-style 330-µH inductors which are 12 x 12 mm black “tiles” intended for reflow soldering (nope, no pins). As shown in the photographs here, for each inductor you bend two pieces of stiff wire (clipped off a leaded component) into a bracket shape, insert the ends in the holes provided, and then solder them flush in place with a little extra solder to create a small ridge. This results in two resting points for the solder areas under the inductors, 0.5 mm or so above the board surface and allows easy access with the solder iron tip to establish the solder connection. As you apply heat with the solder tip, with a gentle press on the inductor block, the thing sinks into place beautifully. It’s like doing reflow soldering manually! The method also gives additional creepage distance to the PCB tracks running under the inductors — no kidding as some of them carrying high voltage like 300 VDC. I really like this ‘defeat-the-SMD’ method and prepared all four 330-µH inductor positions on the board in one go using bits of left over component wire.
 
The green area under the inductor is actually
the PCB surface reflected in shiny solder tin.
LED D2 is identified as ‘L2’ on the PCB component overlay which is slightly confusing considering the inductors are also called ‘L’. Realistically though, if you do not know the difference between an LED and a potted inductor in SMD guise then you should not be in the game for a DIY vacuum tube tracer.

My sub-circuit turned out to work okay: applying 19 VDC from a laptop power supply from the local charity shop produced the correct +5-V and +15-V rails on the board. As a small criticism, the 10-µF electrolytic capacitor C4 is too close to IC 2, a type 7815 regulator. The regulator has no heatsink and its dissipated heat may affect the capacitor’s capacitance and/or ESR.


 
Finished and tested +5 V  and +15 V power supply
section on the uTracer board.

Saved by the bell
Just when I wanted to solder the 16-way turned-pin IC socket for the HIN232 RS-232 converter chip, dinner was announced. My next blog on the µTracer should move faster and reach completion of the PCB assembly, as well as all sub-circuit testing. I work slowly but enjoying it. These tubes are old, old, old -- they can wait! So far, so good.

To be continued in Week 19 (8-12 May 2017).