[Heathkit] DX-35 - Again

[Bill Stewart]

I reduced the grid drive close enough and also had to add more capacitance in parallel with the antenna loading capacitor to bring the 80 mtr min. dip down to a ballpark value. I have one other little oddity with the loading...it jumps out of tune by about 20ma some times, but I can work around that. But it works..about 40-45 watts output and a pretty good tone, depending on xtals. 



But NOOOWWW the dreaded power tranny disease may be cropping up. I have an arcing coming from the xfmr when in the standby position. I can hear it on a rcvr plus with the ear. I found a pulsing fil. voltage on the rectifier tube. I raised the tranny above gnd (just temporally) and get a pulsing reading from the case to gnd plus a neon flickers when hooked up between the case and gnd. So I guess its just a matter of time till I smell the aroma of tar. I have it fused so maybe no fire. I do note that there is no arcing when in the cw position, so maybe I can prolong the trans. life by running it in the cw position only. I also had the same problem with my DX-40, but it stopped on its own...just in the waiting mode I expect. I suppose I could heat up the trans. in an oven and move the tar around. 



I wonder if anyone else has had similar problems (arcing). I know that the pwr xfmr is a weak link in the design of the DX-20, 35 & 40 so guess this is nothing new. (My orig. DX-40, after selling it to a friend, smoked up his bedroom and he was banashed to the backyard smoke house..very appropriate).  Anyone know if a tar-filled xfmr can be rewound. 



This is mostly just a progress report but any comments will be appreciated. Thanks.... 



73 de Bill K4JYS