I have been restoring my early model AR88 (the dial is all yellow, no black) , following MR C’s brilliant guide. I started with the tuning gear mechanism and having cleaned and reassembled with regard to getting all the backlash springs under compression during that process, it now has a really smooth action. I then changed the filter caps and the bath tub caps, changing out of spec resistors as MR C advised.
If you look at episode 5 of Mr C’s CR88 restoration at about 15 mins you can see him changing resistors and noisy capacitors which fed the bias voltage from the supply board to the audio output tube, by adding a little solder to encourage flow and then removing solder and flux with a solder sucker as required. I too had to change these components. I completed the change of these components, switched on and then proceeded to check the bias voltages. Each time I touched on my DMM probe I heard a loud pop and the radio went quiet.
My error is the reason for me raising this topic. I believed, I had removed all the solder from the Joints when using my solder sucker. On the top of the board yes I had, but while heating the joints (which were heavy in solder) some had run through tiny gaps in the lug bases and formed a solder stalactite under the board. Each time I touched a joint on the top of the board it depressed a tiny amount shorting the soldertites on the chassis. Reheating the joints and wiping under the board with braid cured the problem. The radio is already sounding good but I have a lot of work to do yet to get near Mr C’s standards.
Work on this is suspended at the moment while my wife and I enjoy a long break in Spain, but when I return in December I will upload photos, showing my progress.