I'm having a similar problem after installing the KNB2. So, I triple checked component location and applicable polarity and all solder joints for bad joints or bridged/shorted solder pads; removed, checked and re-installed the 2 bandpass toroid chokes, checked the ID number on the caps. Checked the K2 RF board J12, and checked the mods to R88, R89 & R90.
...and the K2 is still nearly deaf as a post. Next, I jumpered 1 & 6 on J12 and could then hear stations all over 40 meters. Checked WWV @ 10 MHz and I thought it was going to blow the speaker before I could turn down the AF gain. So it looks like I did not screw up the K2 itself. That is a relief. I'm guessing the next thing to do is check U2 for correct voltage output, and if that's OK see what I can measure on the RF amp. It's an SMD and mounted on one of those SMD piggy back things for PCBs made for the old school DIP ICs. Kinda frustrating, but it happens. Larry K5END On Tue, 2011-01-18 at 22:43 -0500, Don Wilhelm wrote: > > Try jumpering (with a piece of bent wire) between pins 1 and 6 of the > J12 header. If receive comes back to life, you have a problem on the > KNB2 board. > > Let us know the results. > > 73, > Don W3FPR > > > On 1/18/2011 10:26 PM, Brian Denley wrote: > > I am beginning to think I may have wacked or damaged the PIN diode for the > > T/R switch while adding the resistor for the KNB2. That might explain no > > receive or transmit that I am getting now. Does that make sense? > > Brian > > KB1VBF ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
