IC-736 Part 5: PA Upgrade 10W to 100W

In this video, I upgrade a Japanese IC-736S (10W) to a full IC-736 (100W). The upgrade is pretty simple; the 10W board is removed, and the 100W board is put in. Surprisingly, the PA to Main board wiring is completely compatible. The 736S PSU and Chassis are the same as the 100W 736 as well. During the process, I saw that the dual IRF174 100W PA board is easily capable of over 200W. The video also shows how to remove the LPF board to get to the PA board and how to set the bias levels on the 100W board.

This work took a lot of time and the video shows mostly every step. Sometimes I struggled through routing (or removing) a cable and cut that part out though. But for the most part, everything is shown. The work took approximately three hours, spread out over many nights. I probably spent more time editing the video and trying to straighten out the audio, which was invaded by the sounds of the washer-dryer and the neighbors working on their house. I ended up cutting most of the audio out below 100 Hz.

Some key times:
00:19 New capacitors installed
01:00 Washing machine finishes first load
02:32 LPF Board finally comes out
03:14 10W and 100W board side by side
17:54 10W PA Board removed
20:24 Applying new paste
24:48 100W PA Board inserted
36:58 Bias Adjustment
41:44 Power Read Scaling
42:46 Power Output Test

Overall, the new board is working well. On-air reports are favorable and I am nearly finished messing with this radio.

73,

--E
de W6EL