A repair story from our own Ben EI9IUB.
Today’s repair is on one of my radios – a Yaesu FT-857. While testing a new headset and tuning around the bands, the select knob twisted its last and came out of the front panel and into my hand: disaster!
This encoder is vital to using the radio, so its breaking rendered it a paperweight. The radio itself has been out of production for a number of years now, but unlike most “consumer” devices, amateur radios have very good technical documentation available to end users.
I dug up a PDF copy of the technical supplement, which contains a complete readout of the
internals, block and circuit diagrams and servicing information. Reviewing the parts layout
showed the front panel PCB and revealed the encoder pinout .
Searching for the Yaesu part number returned a number of retailers offering the part for 30 EUR a piece, and further digging revealed that the original part is an ALPS EC12E24244A4, which is appears to be out of production, but thankfully not an issue.
Breaking down the encoder specification – the replacement part needs to be:
- Horizontal Mount
- 24 Detents, 24 Pulses per revolution
- 30mm shaft
- with a push momentary switch.
Mouser to the rescue!
A Bourns PEC12R-4230F-S0024 meets these requirements, and comparing it on the data sheet with the layout shows that it is a drop-in replacement.
I ordered 25 to make the shipping worthwhile, but the satisfaction of paying about a euro for a replacement part made up for it and ensured that I have a good supply for when I break it again!
I zeroed in on the exploded parts diagram and planned the repair; only a few screws were in
the way.
After removing it, you can see the remains of the shaft inside the encoder body.
Unfortunately, I did not take any further photos after this point – I was in a rush to make and test the repair. Thankfully, it worked without a hitch, and I’m now back on air at home.
73 de EI9IUB