OK, folks.? This is going to be the most stupid thing you've heard all day.? Maybe all week.? Or maybe in your lifetime.? Bear with me.? I have some 'splaining to do.? This will be a long read.? And I need some advice.?
I found a great little inexpensive plastic enclosure that the QCX fits nicely in.? That will be the subject of a future post, however.?
Once I had the QCX CCA mounted in the enclosure, I found that the tab of the 7805 regulator was too tall and the enclosure lid would not fit.? I removed the regulator from the CCA and looked at the leads.? They are thicker near the body of the regulator, necking down into a smaller diameter about 3/16 inch away from the body.? I took an emery board and carefully filed the leads down so that they were a uniform thickness all the way along their length.? This allowed the regulator to slip into place flush with the CCA, which gave me enough headroom to close the lid on my enclosure.? Neato!? Just what I was hoping for!? So I soldered the regulator into place on the CCA...? BACKWARDS.? Yep.? I actually did this.? And I didn't notice it.? Now, I'm no noob.? This ain't my first rodeo.? I'm a Senior RF/Microwave Test Engineer with 38 years of experience at a major aerospace company and I've been a ham for over 40 years.? I was a bit distracted due to non-radio related matters.? Still, this kind of thing just doesn't happen to me.? I'm usually very, very thorough!? Well, as I said, I didn't notice the mistake.? I powered up the QCX.? The display lit up for an instant, then the 1 A fuse in my power lead failed (note to everyone -- ALWAYS use a fuse in your power lead because you never know when something unexpected will occur).? I started looking for a cause, and I almost immediately noticed the incorrectly installed regulator.? DUH!!!? I removed it again.? Unfortunately, the plated-through vias pulled out of the board.? Damn!? I looked over the board and it looked like it should still work, so I went ahead and soldered the regulator back into place, correctly this time, and powered up the QCX again.? The display lit up.? I had audio in the headset.? I hit the key, and I had full transmit power.? The VFO was right on frequency.? The CW note sounded clean in my K3's receiver.? I was overjoyed!? That is, until I realized that I didn't hear any signals coming in on the QCX.? I switched the antenna over to the K3, and the pan scope showed strong signals all across the band.? The QCX wasn't hearing any of them.? I switched K3 into my dummy load, dialed the K3's transmitter down to 0.1 Watts, and hit the key.? The QCX did not hear the K3's signal.? CRAP!? I set up the QCX to allow me to run through the alignment checks again.? It ain't hearing itself.? No 700 Hz tone.? No received signal at all.? I get good audio, and it has the characteristic sound of the 200 Hz filter.? Everything seems to be functioning correctly.? But the receiver is not hearing a bloody thing.? What the devil did I kill?? I can't believe this!? I was sooooo close to being all finished with this project, and now it's broken!?
Anyone have a suggestion as to where to look for the failure?? This one has me stumped.?
73/72,
Dean K5DH? --? very depressed!
20m QCX msn 612
