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I made the mistake of watching the construction videos after I'd already started my QMX (V3, high bands) build. Realized that putting the diodes in the right way around isn't enough. The position of the bodies has to leave room for the toroids.?? After checking my parts bin to be sure I had some spare leaded 1N4007s, I cut out D511 and D509, which looked like they'd cause problems. D511 was easy, as there was still plenty of room to get the solder sucker in there. D509 is the problem. The pre-installed inductors on either side mean I can't get a clear shot with the solder sucker. Several attempts with that, and also braid got me nowhere. Complicating things, my bin 1N4007s have thicker leads. No problem if the holes are clear, but they're not. Heating up both leads I managed to get it mostly in there, but that 6-layer board makes it really hard to keep the both sides hot and it's fairly stuck. |
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I have a buncha 1N4007 with leads diam. .0185"/0.47 mm. Where do I send how many if the wire is small enough?
I went through clearing solder holes for T507. Solder sucker so huge to not work....uses solder wick both sides and drilled 'em out with real skinny bits from a #61 - #80 drill set. Held them in a pin vise. Picked drill sizes just bigger than the wire. Measured drills and wire with digital caliper. You can scrape the leads to reduce the size a little. The thing to avoid is drilling too big and breaking any contacts? through-hole plating. I did not find any with T507 but drilled just a smidge over lead diameter, anyway. -- 73 Karl KI4ZUQ |
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Ouch.
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If you had sent this before changing out the diodes I would have said just leave them. I too soldered them with the less than desirable orientation. When I starting test fitting the wound toroids I realized they should have been the other way. But with a little wiggling and living with a little 'tilt' I got them in. Figured I could go back and redo if performance was compromised. Didn't need to. Everything worked fine. Now, as to your questions. And please don't take my suggestions as gospel. Just thinking out loud. 1) You could assemble the display board and the necessary header connectors and stand offs to the main board. He sure to bend over the one large holding tab on the back of the LCD itself.? Plug in the display board and inspect closely for interference with the two higher diodes. If clear, move along. This is of course without power! If the clearance is too close for comfort but there is a little room, perhaps place a piece of insulating tape for insurance.? 2) If there is definitely interference, one or both will probably need to be dealt with. 3) If you only need to get the one lead out of the way on 509, as you hinted at, you might be able to bend it over, ever so gently. Perhaps grab across the top of the base of the diode with a thin hemostat, engaging the lead in two places and then use another small tipped pair of pliers to tease the loop to be a bit more horizontal. 4) Cut the bare lead of the diode diode a few millimeters up from the main PCB. Then pull out the one bare lead and the diode body with the other lead, one at a time, with fine tweezers while applying heat to the pad joints.?? Clean up the pads with solder wick as carefully as you can. Then ... 5) Using a fine pin vise and some really small drill bits, BY HAND, open up the through holes. Start small and work up in size of bits until you can just get the leads of the correctly sized diodes back in.? I had to do the hole opening a couple of times myself on my QMX. Full on operator error. Worked fine. PS In your picture, the one bare lead of diode 508 looks like it could use a bit more solder. Or, could just be a shadow. If it's well soldered on the bottom side of the board, it will probably be OK.? 73 Greg KI4NVX
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Karl