++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From: "Monty Shultes" Subject: [Elecraft] RF Board building strategy I have built 2 K2s. It saves some desoldering of jumpers and parts if you install the interface sockets for the options as you build the K2's RF board. Several jumpers can be installed in these sockets instead of on the RF board. W5 goes in J12 - look at the board to verify which pins W2 goes in J9 W3 goes in J10 There is a cap, C167, near the SSB board large socket that can also be temporarily placed in the socket instead of soldered to the board. It is removed when the SSB adapter is installed. It is wired directly to 2 pins of the socket on the circuit board. R88, R89, and R90 are changed if you install the Noise Blanker. I changed these as I built the RF board. (This changes the overall gain upwards a tad, but not a problem.) However you do it, have a ball! ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 11 Mar 2001 08:03:53 -0700 From: "Ken Lotts" Subject: RE: [Elecraft] New K2 Owner Hi Doug FWIW, Here are my K2 building notes (I have only built one K2 and am not an expert): 1: The first step on page 18 of the manual, Highlight the words "flat against the PC board" *and* "PARALLEL to the board".. Not a good place to make a mistake. 2: Illustration of voltmeter assembly on page 42: Make a note that you can use a radio shack part 278-016 (red lead) here in place of the hookup wire shown in the illustration. The Radio Shack lead (cut to size) gives you a very convenient clip probe at the end of the wire, plus the miniature red probe wire is perfect for the job... This is sort of a "fluff" project but it makes for a much nicer looking internal DVM probe. 3: At the *end* of the last bullet in the first column on page 57, add the words "(see page 98)" 4: On page 61, in the "I.F. Amplifier Alignment section, note that the "Spectrogram" program can be helpful to identify the somewhat shallow peak of L34. 5: Numbered step "9" on page 98, Highlight the words: "This will force the K2 to re-measure the BFO frequency". 6: On page 77, Highlight ALL of the last information bullet. 7: Overall note regarding Toroids: The illustrations regarding the direction of the flow of the wire around the cores are always important. 8: If you have an antenna noise bridge, you can use it as a noise source during alignment. Very handy! (Note that the "spectrogram" program is -probably- the defacto standard method to tune passband filters) I hope this helps.. Please forward what other tricks you receive to me so that I can learn as well.. Good luck! Ken Lotts aa7jc +++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 11 Mar 2001 22:24:28 -0800 From: "Logan R. Zintsmaster" Subject: Re: [Elecraft] New K2 Owner Doug, 1. Don't stay up too late working on your K2, for obvious reasons. All of my problems occurred when the first digit of the time was a zero. 2. Watch out for P1 on the RF board. It goes on the BOTTOM of the board. (The voice of experience.) 3. I second the comment about the toroids. Check the board and note where the leads will go before you start the winding. It makes it easier to get them into place. There are a lot of them but they really go quickly. 4. Use the Builder's Resources on the Elecraft web page. The pictures are especially helpful. 5. Don't be afraid to ask for help, either on the reflector or privately. Elecraft and Elecraft owners provide lots of good support. 6. Follow the recommendations on solder and soldering iron. I used the 2% silver, .022 dia. solder from Radio Shack. The 1.5 oz roll is MORE than enough. 7. Take your time and have fun. Logan, KZ6O #1609 Doug Person wrote: > Greetings all, > > I now own K2 #1920. Just purchased directly from Eric's hands to mine. I'm > really quite excited. I was at Dayton when the dynamic duo first announced > the K2. And I've been dreaming ever since. They came to Charlotte this > weekend for our hamfest and I had the great pleasure to shake each of their > hands and offer my greatest congratulations for doing what I consider to be > an absolutely remarking thing: creating a company that probably many of us > (certainly I do) wish we could do, and, most importantly, apparently being > very successful at it. > I'm a fairly experienced builder having worked my way through a substantial > portion of the HeathKit catalog so many years ago and have recently built > many of the current crop of QRP xcvrs such as the DSW, SST, MFJ Cub, and the > PSK-20. But I'd be happy to listen to anyone's experienced advice before I > begin. So any thoughts anyone has to share to someone just about to warm up > the iron and begin? > > 73 to all from Doug -- W4DXV ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 24 Mar 2001 11:56:14 -0700 From: "James E. Fuller" Subject: Re: [Elecraft] Build order for K2 & accessory boards At 10:36 AM 3/24/01, you wrote: > > "James E. Fuller" wrote: > > > I liked putting the module connectors and stuff on the main boards as I > > went, so that I didn't have to do as much deconstruction when I added the > > modules after building and testing the main unit. > Having read the cautions about Q7 and Q8, metal pieces and so on > in the >module manuals, getting some of the stuff in ahead of time seems a capital >idea. Besides the connectors and standoffs, what other components in the >160m, NB and SSB modules can be installed without messing up testing of the >main K2 unit? It's all in the manuals. I benefited from building the modules before I built the main unit, so I had read through their installation instructions. I did not read carefully enough to realize that I could save some unsoldering operations, but that was not a big thing. This list is not exactly what I did, it is what I would have done if I had studied it sufficiently beforehand. I actually soldered in the Ws, then later removed them. I did install all of the add-on parts on the Front Panel Board and on the RF Board as I was building them, so that I did not have to go back and redo them. This saved the hassle of removing and re-installing the heat sink and connecting it to the PA transistors. After it was built, I did try removing each module and placing jumpers in the connectors as described in place of the Ws, and it all worked perfectly (the NB module required replacing a couple of resistors also...). Since this is my own interpretation, and not Elecraft approved, consider it unreliable and check the manuals and the schematics yourself. Glaring and stupid errors are not my fault,-- the computer did it. In preparation for the 160m module, as you build the RF board, install the RF board parts that come in the 160m module kit: Install C13 and C14 Make sure C68 and C153 are the correct values (see 160m instructions). Mine were. Install connector J14 Omit W1; instead, jumper J14 pins 1 and 7. In preparation for the NB module, as you build the RF board, install the RF board parts that come with the NB kit: Lightly solder R88, R89, and R90. You will remove them later. Install connector J12 Omit W5; instead, jumper J12 pins 1 and 6. In preparation for the ATU module, as you build the RF board, install the RF board parts that come with the ATU kit: Install connector p6 (aux rf). In preparation for the Battery module, as you build the RF board, install the RF board parts that come with the Battery kit: Install P3 (aux 12v). In preparation for the SSB module, as you build the Front Panel Board, install the Front Panel Board parts that come with the SSB kit: Install C4-C8 Install R13 Install RP3 Install Q3 Install P1 (mic configuration connector). (These parts' installation is described in the SSB module manual, pg. 16 and in the basic K2 manual, pg. 27.) Also in preparation for the SSB module, as you build the RF Board, install the RF Board parts that come with the SSB kit: Solder C167 lightly, you're going to remove it later Make sure that you install the grounding jumpers for the filter crystals correctly. See the drawing in the SSB module manual. Install connectors J11, J9, and J10 Omit W2 and W3; instead, jumper J9 pins 1 and 3 and J10 pins 1 and 3. The installation of the parts for the add-on modules is included in the manual for the basic K2 on page 68. When you place the jumpers in the connectors, just use a component lead, one of the regular ones, not one of the big ones. Form it into a U shape the right size and insert the legs into the connector. Enjoy, - -- Jim Fuller +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 02 Jun 2001 23:18:47 -0600 From: Larry East Subject: Re: [Elecraft] K2/1946 At 01:44 PM 6/3/01 +1000, Bill Scovell wrote: >The Voltage/Current display which has worked perfectly to date is now >showing Zero volts accompanied by a periodic 'Lo Battery' message >although the current readout is still present and correct. A regulated >13.8V supply is being used and the set is receiving OK on 7MHz. > >Any ideas? Yep! You flipped the voltmeter switch (S1) into the "external" position! The switch is on the upper edge of the control board next to J5. (Been there, done that... :-) 73, Larry W1HUE ++++++++++++++++++++++++++++++ Date: Fri, 15 Jun 2001 13:43:36 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] (K2) Alignment II, audio problems Daniel >I'm into the Alignment and Test, Part II on my K2. It passed the Ocillator >Calibration, PLL, VCO, and BFO tests. But, there is a problem with the >audio. The audio sounds like a high pitched and muted "buzz" on C and L >modes, but sounds normal when I switch to U. On U, I do hear signals, but >on C and L, the audio is so bad, I can't tell if the signal is getting >through. Don't sweat the small (at the point) stuff, pal. What you're hearing is nothing more than the BFO setting for the various modes being a bit out of whack (a commonly used technical term). This problem will be addressed when you get to the point of performing the CAL FIL adjustments a bit later in the manual. Basically, what you're hearing is the current frequency response of the xtal filter, but because the BFO is not properly adjusted, the passband of the filter is not properly centered, thus the noise coming thru the filter sounds either too high or too low. Tom Hammond N0SS ++++++++++++++++++++++++++++++++++++ Date: Fri, 15 Jun 2001 20:51:37 -0700 From: Daniel Salo Subject: [Elecraft] (K2) Alignment II, audio problems (Solved) Thanks to everyone for your help with this. As many have suggested, it was a filter calibration problem. I recalibrated the filters and the audio now is FB. This really pulls in the signals now. I'll take a night off from building to tune around 40m and start on phase III construction tomorrow. 73, Daniel, KF6QZQ K2 #2100 >I'm into the Alignment and Test, Part II on my K2. It passed the Ocillator Calibration, PLL, VCO, and BFO tests. But, there is a problem with the audio. The audio sounds like a high pitched and muted "buzz" on C and L modes, but sounds normal when I switch to U. On U, I do hear signals, but on C and L, the audio is so bad, I can't tell if the signal is getting through. > >Any ideas where to start looking for this one? > >73, >Daniel, KF6QZQ >K2 #2100 +++++++++++++++++++++++++++++++++++++++ Date: Wed, 15 Aug 2001 17:29:42 -0400 From: "Mark J. Dulcey" Subject: [Elecraft] K2 Un-Modules I wrote an article about some little things I built recently... I'm thinking this could become a Tech Note at Elecraft, but I'd like comments first. Here's the link: http://mail.buttery.org/mark/unmodule/ Let me know what you think... The beginning of the article (to give you an idea what it's about): The K2 modules (KSB2, KNB2, K160RX, KAT2) add useful capabilities to the K2. However, there are times when you might want to remove one or more modules from your K2. Installing many of the modules requires that you remove jumpers and/or components from the RF board of the K2, so you can't remove the modules by simply unplugging them. The usual procedure for removing a module is to unplug the module, and then put back the removed components and jumpers. If you are permanentely removing the module, that's fine, but you might want to take it out temporarily, for any of the following reasons: * Troubleshooting a problem * Comparative performance testing (how does a module affect sensitivity, dynamic range, or ultimate filter rejection?) * Minimizing weight and/or power consumption for field use Enter the Un-Modules! By building these simple circuits on header connectors, you can remove one or more modules from your K2 without any need to modify your RF board. The Un-Modules are simple and inexpensive to build, too! +++++++++++++++++++++++ Date: Sun, 19 Aug 2001 10:03:02 -0700 From: Vic Rosenthal Subject: Re: [Elecraft] K2 Improving QSK Performance? Dave Gingrich wrote: > > Has anyone been successful in improving the QSK performance of the K2? I was slightly disappointed with not being able to hear between the dots at 25 wpm. The release notes for the new firmware suggest changes to control board R17 may improve things. Has anyone played with this? I have not installed the new firmware yet, but at Wayne's suggestion I did try reducing the value of R17. While sending dits with the QSK parameter set to 001, I found that I could go as far as putting a 1 M resistor across the original 3.3 M resistor before I started hearing clicks. This did improve QSK speed, but it still isn't fast enough to hear between dits at 30. Wayne indicated that the new firmware would improve the speed some more. 73, Vic, K2VCO Fresno CA ++++++++++++++++++++++++