The Yeasu FT-817 would have to be one of the most revered and iconic QRP radios of all time. But this doesn’t mean it doesn’t have its faults.
Take the DC input jack, for instance.
This is a crazy design that is prone to failure, especially if the radio is used as intended: out in hostile environments. The input jack on the DC power chord features a flimsy right-angled input plug that is prone to become problematical due to its unprotected mounting situation at the rear of the rig. What happens, and this happened to mine, is that the 1.5mm annulus of plastic at the end of the plug snaps off and becomes stuck around the input shaft inside the jack. And as long as you continue using the damaged plug all remains well and the radio continues to work. But come the time when you decide to use a different power chord, this is when you run into trouble.
In my case this happened when I ordered an FT817 PowerPole Adapter from Sotabeams (https://www.sotabeams.co.uk/ft817-818-powerpole-adapter/). The thing secured nicely to the back of the radio but I couldn’t start the radio. No power was getting through. So I emailed Sotabeams and Richard replied, explaining that my problem was in all probability the failure of the plug as described above.
It was time to take action and fix the situation.
I started by removing the cover of the radio, unclipping the speaker cable and examining the DC jack. I could see the offending ring with the aid of my trusty Mini Maglite. I decided to take a more drastic approach, and instead of trying to remove the little black ring, I decided to remove the plug and, in its place, solder in a new power cable that is terminated in PowerPole connecters which are housed in the Sotabeams housing.
I then removed five retaining screws from the PCB and the ribbon cable, securing it safely out of the way with sticky tape. I decided not to chance my luck by removing the larger ribbon cable: it wasn’t in the way in any case. The two thick cables were twisted out of their housings okay and pushed out of the way.
Then came the tricky task of unsoldering and removing the DC input jack. I tried to unsolder the connections but found this didn’t work. And I didn’t want to risk overheating the board or damaging some of the minute surface mount components that are absolutely everywhere. So I reached for my side cutters and cut the jack off.
Once the main heatsink strapping was cut loose I prized the thing up and used my soldering iron to assist in loosening the remaining terminals.
With my DMM I determined which terminal was the ground and which the positive. Then I prepared a short length of red and black power chord, connected a pair of PowerPoles and swapped this arrangement with that which came with the Sotabeams adapter. I then fed this chord through the hole in the radio’s chassis and screwed into plase the Sotabeams adapter. All that I needed to do now, before assembling the radio’s enclosure, was to solder the positive and negative leads of the chord to the respecrive tabs on the PCB.
I then screwed the five chassis screws into position again, connected up the two cables and ribbon cable, and sat back to admire my work.
I then connected my SLA battery to the back of the radio and pressed the power button. It fired up beautifully!