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I finished the KXB3080 adapter today. Receive seems OK, but transmit power
into a dummy load is only about 0.2 watts on all bands. (It was about 3 watts with the KXB30.) I suspect a short somewhere because Q6 gets hot and TX current drain is above normal at 850 mA, but I'll be darned if I can find it. The voltages at Q1, Q4, Q4, Q5, and Q are normal. I;ve also done the mod to increase the L3 windings. I'll have a fresh look in the morning, but meanwhile, has anybody else seen this problem? Thanks es 73, Bruce N7CEE _______________________________________________ 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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Bruce, N7CEE, asked:
I finished the KXB3080 adapter today. Receive seems OK, but transmit power into a dummy load is only about 0.2 watts on all bands. (It was about 3 watts with the KXB30.) I suspect a short somewhere because Q6 gets hot and TX current drain is above normal at 850 mA, but I'll be darned if I can find it. The voltages at Q1, Q4, Q4, Q5, and Q are normal. I;ve also done the mod to increase the L3 windings. I'll have a fresh look in the morning, but meanwhile, has anybody else seen this problem? --------------------- On the LPF1 board, did you check lead L2-1 on the LPF1 board to see if it's shorted against the solder pad for lead L2-4? L2-1 is the lead that runs around the end of the LPF1 board to a solder pad right behind it. If you left the 1/8" on insulation on that lead the instructions called for, you shouldn't have any trouble there, but if you tinned it up too high and then pulled the wire tight against the LPF1 board, it can short against that pad. Just pull it away a bit. One builder who tinned the wire too high took a very tiny bit of the green wire insulation and threaded it over the L2-1 lead and positioned where it'd prevent the L2-1 lead from being pushed against that solder pad 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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In reply to this post by Bruce Grubbs
I found the problem- a solder bridge between pads A and B on the KXB3080
board. Thanks for all the suggestions. 73, Bruce N7CEE _______________________________________________ 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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