Don, thanks. I understand about the band pass LC section and that is what perplexed me.
Late last night I found and corrected a tiny solder short hidden under the connector on the KNB2 board. Of course it had to be pins 1 & 2 and you know what that would do. Had to call it a night at that point per the whole work/job/employment thing for this morning and will reinstall into the K2 & test it tonight. If this turns out to be the "only" problem I'll be a happy Ham. Thanks & 73. LK -----Original Message----- From: "Don Wilhelm" <w3...@embarqmail.com> To: "Elecraft Reflector" <elecraft@mailman.qth.net> Cc: "L Kendall" <k5...@att.net> Sent: 3/21/2011 8:06 AM Subject: Re: [Elecraft] [K2] Ooof.. Update That last R should have been R9, sorry for the typo (it is still morning - need more tea) 73, Don W3FPR On 3/21/2011 8:59 AM, Don Wilhelm wrote: > Larry, > > You are trying to analyze too much in the KNB2 without looking at the > schematic. The signal always passes through the Bandpass Filter. It > only goes to the amplifier to detect noise. > So check the toroids L1 and L2, C3, C4, C6, C7, R8 and R8. > The RX signal should pass through the KNB2 with only those components in > place and working. > Also check the soldering of P1 and its mating header on the K2 RF Board > = make certain pin 1 has been soldered on both. > > 73, > Don W3FPR > > On 3/21/2011 1:21 AM, L Kendall wrote: >> 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 >> > ______________________________________________________________ > 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 > ______________________________________________________________ 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
