QCX-mini... smoke
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Finished my QCX mini build (20m) about a week ago and was only getting about 1.38 watts out of it so I decided to try Hans's tune up video from 4 years ago.? I took out 2 turns from L3 and then played with the winds on L1 thru L3 and was able to increase the output to 2.05 watts.? While adjusting the turns on L2 I noticed the first/last turn was crossed with the adjacent wind so I desoldered and removed the cross and its turn, then started adjusting winds to see if the power came up.? Well, the power out came up to 2.5 watts, but while I was fidgeting with the turns the power dropped to 0 watts and smoke erupted from ic TI37A2QDM/CBT3253C.? What did I do wrong?? I am not skilled enough to change the 16 pin IC so I'll probably just have to chock it up as a poor decision to play with the winds, although, did having the cross in L2 cause my low power out in the first place?? Any advice would be appreciated.
Rich, ad?sn |
开云体育?Rich,? Don’t despair. ?Get some low temp ChipQuick and read/watch re the use of that interesting product. ?Beware there are a few different ChipQuick products, each for different kinds of repairs. ChipQuick keeps the solder on all the pins liquid long enough to remove the chip. ?Then clean up the board with solder braid and alcohol to remove the rosin residue. ?Then with the new chip (after you have looked for and found the error) solder two pins down, one on each end. ?Then flood all the pins with solder and then use the solder wick again to remove the excess solder. ?ChipQuick works well for this last step too. ?You may not be able to get a working board in the end but what you learn doing those steps will prepare you for future repairs.? |
rsmith
David Wilcox K8WPE
Dave K8WPE