Finished the building yesterday just before we had to leave to go to a concert. Whew! lots of tight space work! Took me a bit longer than it should have, because when I got to the part that says, "OK now power it up and see if your receiver is still working," it wasn't. Many, many passes over the board with the light and magnifier later, I found a solder bridge - I guess I was swinging the iron around a bit too vigorously while trying to hold the iron, the PCB, and the solder sucker all at once. After I cleared that, things went smoothly.
While I was at it, I did the TX power mod (my TX was always a bit low) and the L3 rewind. (Now I'm getting enough power that I need to back off just a hair on R4). Power is a bit lower on 80, and I can't get 20 to be lower than 40 no matter what I do with the L2 green winding - but I think I can be content to live with it. I just came in from the back yard, where I put my old standby 50 ft wire sloping into a tree, with the 50 ft counterpoise lying on the ground ( a 50 ft roll of speaker wire from Radio Shack, split in half) to see how the ATU would handle it - got an indicaed 1.1:1 SWR on 30, 1.0:1 on all other bands. Yea! Now I'm ready for QRP To The Field a week from tomorrow! 73 Ray K2HYD _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I finished the mods to the board and went through the receiver alignment on 20 and 40 to discover that although I was getting some signal, it was way way down from before.
After reviewing the email thread on the other deaf KX1, I checked the resistance to ground from both sides of L6 and found it was shorted. All the joints in the area looked good, and no bridges could be seen, so I started to look at the top of the board and noticed that T2 sits right on top of one on the ends of L6. I lifted T2 off the board slightly so there was no contact, and checked the resistance again - it was good. About 1000 ohms with R1 in the minimum position, and 1.5 - 2.5 ohms at the max, as Ron decribed in the prior email. Connecting the KX1 to a noise source in this condition gave a nice loud noise signal. How should I go about fixing this? I wouldn't think the enameled wire or the core would present an opportunity for a short. The pad of L6 is not near any tinned wire coming from T2. Should I put some insulation there? A bit of tape maybe? Thanks Mike N2HTT KX1 099, currently in surgery _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Mike N2HTT wrote:
T2 sits right on top of one on the ends of L6. I lifted T2 off the board slightly so there was no contact, and checked the resistance again - it was good. About 1000 ohms with R1 in the minimum position, and 1.5 - 2.5 ohms at the max, as Ron decribed in the prior email. Connecting the KX1 to a noise source in this condition gave a nice loud noise signal. How should I go about fixing this? I wouldn't think the enameled wire or the core would present an opportunity for a short. The pad of L6 is not near any tinned wire coming from T2. Should I put some insulation there? A bit of tape maybe? ---------------- That's why L6 had to be moved: T2 sits on the spot where it was originally on the top of the board. Clearly, some enamel on your T2 winding got worn off or punctured. It does come off rather easily! Yes, I'd put a bit of tape under T2 at that spot. That should take care of it FB. Thanks for the heads-up. I sure alerts me and perhaps others should that situation occur again. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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