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QCX 20 T1 WOE

Lloyd K3ESE All Messages By This Member #33693 I really thought I'd be taking my time and doing everything right. but then I noticed that I installed the three smaller windings on T1 wrong. After ripping it out and redoing it, I've wrecked pads on the bottom of the board. Primary 1, the center small winding, is shorted, somewhere, to S3, the large winding. Argh. Can someone tell me some spots to check for continuity with various places on this transformer that I can use to try and salvage this, maybe by adding some jumpers? oy red arrows point to P1. orange is S2, blue is S1, yellow is S3
Peter GM0EUL All Messages By This Member #33697 Hi Lloyd I may have misunderstood what's happened but looking at your picture I think the bottom yellow dot (S3)? and the left hand red arrow (P1) are both connected to the ground plate.? I've also looked at the schematic and that is how it is supposed to be.? So it is correct to see continuity between P1 and S3.? Its likely that all is well. 73 Peter
Curt wb8yyy All Messages By This Member #33698 Lloyd Likewise I don't see any board damage. I myself might be tempted not to remove those wire stubs, but back them up toward the top and use them to attach to. Proceed with least risk to the board. You can later stake appropriately. This coil is a work of art to cancel the unwanted sideband, inspect carefully before soldering it. Use the picture book that Hans gave us. Uh ohs happen. Did one yesterday to an accessory homebrew item for my ubitx, trying to add a S meter (for next time you ask me for RST when you give me less than a watt) 73 from dude across the lake
ohwenzelph All Messages By This Member #33700 First get some q tips and 90+% alcohol and clean the crud up so you can see what’s what. Firm but gentle. You will not be able to get rid of all the black but should be able to make it much easier to inspect closely. Mine looked similar, it was surprisingly difficult to get the wires out of those plated thru holes without lifting and destroying the pads. If I had it to do again I might leave a toroids thickness length (or more) of wire extending from the top of the board and then figure out how to snuggly solder the new winding to that. Too late now. I did remove a bit of solder mask from the trace coming from hole that no longer has a pad on the bottom side, having the wire come thru that hole & then fold down on top of that trace and solder the wire to the trace. No where near as pretty but I completed the rest and the radio works well.?
James Daldry W4JED All Messages By This Member #33702 开云体育 Hi, Lloyd Step 1 - Take 2 full size paper towels and fold them into a pad maybe 6 inches on a side. Step 2 - Rubbing / Denatured / Isopropyl / Gin / Vodka and an old toothbrush - Give the area with the appearance of a battlefield a good scrubbing. Hold the board on its side and allow the alcohol to run down into the towel pad. Follow while still wet with a dry towel, patting it down. Now that you can see the board, inspect thoroughly and double-check that you have the right wire in the right hole. Once you are sure you have repaired all visible opens and shorts, give the board a few minutes with a hair dryer on high, both sides. 73 Jim W4JED On 4/20/19 12:35 PM, Lloyd K3ESE wrote: toggle quoted message Show quoted text I really thought I'd be taking my time and doing everything right. but then I noticed that I installed the three smaller windings on T1 wrong. After ripping it out and redoing it, I've wrecked pads on the bottom of the board. Primary 1, the center small winding, is shorted, somewhere, to S3, the large winding. Argh. Can someone tell me some spots to check for continuity with various places on this transformer that I can use to try and salvage this, maybe by adding some jumpers? oy red arrows point to P1. orange is S2, blue is S1, yellow is S3
George Beeler All Messages By This Member #33703 开云体育 I have found that a hard toothbrush instead of q-tips makes board cleanup much easier as the cotton wants to shred on any solder/lead/wire standing up and the base of the solder joints don’t get as thoroughly cleaned. ? 73 George N8AHT ? Sent from for Windows 10 ? toggle quoted message Show quoted text From: James Daldry W4JED Sent: Saturday, April 20, 2019 4:35 PM To: [email protected] Subject: Re: [QRPLabs] QCX 20 T1 WOE ? Hi, Lloyd Step 1 - Take 2 full size paper towels and fold them into a pad maybe 6 inches on a side. Step 2 - Rubbing / Denatured / Isopropyl / Gin / Vodka and an old toothbrush - Give the area with the appearance of a battlefield a good scrubbing. Hold the board on its side and allow the alcohol to run down into the towel pad. Follow while still wet with a dry towel, patting it down. Now that you can see the board, inspect thoroughly and double-check that you have the right wire in the right hole. Once you are sure you have repaired all visible opens and shorts, give the board a few minutes with a hair dryer on high, both sides. 73 Jim W4JED On 4/20/19 12:35 PM, Lloyd K3ESE wrote: I really thought I'd be taking my time and doing everything right. but then I noticed that I installed the three smaller windings on T1 wrong. After ripping it out and redoing it, I've wrecked pads on the bottom of the board. Primary 1, the center small winding, is shorted, somewhere, to S3, the large winding. Argh. Can someone tell me some spots to check for continuity with various places on this transformer that I can use to try and salvage this, maybe by adding some jumpers? oy red arrows point to P1. orange is S2, blue is S1, yellow is S3 ?

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