Component identification - Panasonic RF-537 power/volume board

Beginner here! Thanks in advance! (Limited to 3 pics)

I’m attempting a restoration of a late 70’s early 80’s portable Panasonic radio (RF-537). :slight_smile:

Specifically, there’s a small board (pic 1) that handles
–power switching between battery (red+black wire pair) and AC (blue+blue+black wire set), and
– a volume slider for the single 3" speaker (blue+white wire pair)

On the board, 2 of the blue leads from the AC transformer are each connected to their own set of
– a small green ceramic cap? (Labeled 103Z; 6mm diameter)
– a small black barrel diode (pics 2&3 ; markings of 10E and 1B on each side; 5.3mm x 2.8mm)

Hoping to get some help with an appropriate replacement for the diodes?


The diodes/caps are very likely intact and in working condition; they’re the sort of parts that can last almost indefinitely if not mistreated, and this configuration (likely schematic below) was a cheap & sloppy one with much room for variance. Most any 1N400x device would likely do the job, and any halfways respectable 10nF through hole cap likewise. But again, no point in replacing those if they’re not demonstrably broken.

The slide pot could be a trick, as they’ve become much less popular over the years. Get out the ruler & see if you can find anything even close mechanically; measure resistance value and look for something similar as a next step.

Slide switches aren’t quite as unfashionable as slide pots yet, and what you’ve got there is likely an ON-OFF-ON function (double throw) with one or two poles. Again, mechanicals are a big thing to start narrowing down the options, dont’ fix what 'aint broke, and have a replacement in hand before ripping stuff out.

The electrolytic cap on that unit is perhaps the only item that might warrant replacement as a matter of routine, since those do have a decidedly finite useful life.