Re: Letting the smoke out
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there's a 5 v regulator-U3 next to Rv1.? Carefully check for output on U3.? Also maybe the Rv1 got fried. If you replace Rv1 put a tick mark where the old one is set or measure for ohms. You need a decent iron re the ground plane is a heat sink. Look at the condition of R150 (47ohm) (at the corner of Rv1 case.
Good luck Larry WA9DOH
My eyes are sore from looking at this SMD Hi.? Need a magnifier/lamp.
On Thu, Mar 16, 2017 at 5:52 PM, KD8CGH <rkayakr@...> wrote: I received my BITX40 kit and wired it up on my workbench. The receiver worked well and I made three QSOs before disassembling it to install in a homemade case. While reassembling the IRF150 tab shorted to the case? with the power on. This blew the 10 amp fuse on my 13.7 volt power source and literally produced smoke from around C157. Fortunately the receiver still functions but I get no transmit power out. It appears that C157 was not damaged and it is not shorted. I checked L8 and T7 for continuity and they seemed OK. I replaced the IRF150. What I see now: 0.17 A draw on receive, rises to 0.29 A when PTT pushed but goes no higher about 9 volts on the drain of the IRF150, drops to 0.0 volts when PTT pushed, speaking into mike causes slight negative voltage (-0.15V) Any suggestions on what (and how) to check next? ??? Thanks
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