Monday, October 18, 2010

N-gen

I ordered the N-gen kit last Thursday and it arrived in USPS mail today. It was a very simple kit, with very few parts. I guess I still don't understand Elecraft's pricing on this (a tiny fraction of the parts in the K2 at about 8% of the cost), but it was fun to put together and will be a nice tool in my shack.

Here's the N-gen, ready for running through the filter alignment procedure.
Here's a hi-res closeup of the completed N-gen. The MAR-1 was the only component that I had to puzzle over, but finally decided to install it using the SMT technique I used when I built my PSK-20 last year, i.e., I put some solder on each pad first, placed the part, then soldered down one lead, then gronched down and soldered the rest.

The next step will be to align all the filters using Spectrogram and the very detailed procedure described in this document at N0SS's web site.

Friday, October 8, 2010

Success!

First contact with the new rig: on 20 meters with UA6YH (Alex), east of the Black Sea. My report was 559 ... very satisfying, especially for 10 watts and a not very high dipole!

Thursday, October 7, 2010

"This completes assembly of your K2"

Well, "two or three hours" was a bit optimistic! It actually took quite a while to get through the last four transformers. I was being extra careful about getting the spacing right. T4 turned out to be fairly brutal; getting those two "link" windings into their respective soldering pads right next to T3 was nearly impossible for the size of my fingers.

However, by late afternoon, I completed assembly of the RF board (whew!!) and plugged the three boards together and mounted it all in the case, ready for Integration Test 3 and alignment.
I ran the N6KR method for setting the 4 MHz reference oscillator, which worked really well, and ran through the receiver and transmitter alignment steps a couple of times (last night when I was too darned tired, and then again today when I was fresh and actually read the fine print!!) ... and depicted is the result ... Elecraft K2 S/N 6982.

Actually, I did as much of the alignment as I could. I don't own a noise or signal generator and 10 and 12 meters were so dead there was nothing for me to use to peak the band pass filters. Also, I don't own a dummy load and don't have antennas for all the bands either, so I couldn't peak all the band pass filters by the transmit method either. I plan to build the KPA100 (100 watt module) next (heh ... stay tuned for more blog posts later this year) and will get a dummy load as part of that project. I also will probably get Elecraft's N-GEN noise generator (although I think they charge too much for it!). With noise generator and dummy load in hand, I will be able to complete alignment for the other bands.

Looking forward to getting on 20 meters tomorrow!! Right now ... very satisfied and very tired.

Tuesday, October 5, 2010

Home Stretch

I spent a couple of days just enjoying listening to 40 meters, and had to push myself to disassemble the K2! At that point, I decided to try to push through to finish assembly; there were only a few pages of RF board construction left to go to arrive at Integration Test 3. So, I've put in a lot more daily hours in the past few days and am now close to finishing the RF board.

Having documented my stuffing the first resistor on the Control Board, I thought I would amuse myself by also documenting stuffing the last resistor as well. R44 is the last small component to be stuffed, as well as the last component (except for the PA transistors) to be mounted on the bottom of the board.
So, here's the whole RF board. All that remains to be mounted are 4 transformers, that I still need to wind, and the 2 PA transistors. Although it may not look like that many in the photograph, there were a lot of capacitors to be stuffed, many of which were the tiny ones that needed to have their leads formed to fit the solder pads. The last step in today's construction was really speeded by my having already wound L16 through L24 a week or so ago.

Two or three more hours should see me through to Integration Test and Alignment 3.

Most of the way through page 70 ...

Friday, October 1, 2010

Integration Test 2

I completed RF Board Assembly, Part II. More on that in a moment but first some pics of recent interesting construction:

Here is the engineering change that added D40 and D41, connected on the bottom of the board to pins 3 and 4 of T7. I soldered the leads from the "top" diode to the leads of the "bottom" diode and then only had to deal with the bottom diodes leads to actually solder to the bottom of the board. It took a while to get the leads shaped appropriately.
Here's L33. For a change, I looked at the e-mail reflectors before I started working on this component. Helpful hints were (a) that R116 was only there to hold L33 down and (b) that tweezers were the right tool for forming L33's leads around R116's leads. I just used a little pair of scissors to trim off L33's excess leads after soldering. And you can see the SMTB1 daughter board installed in D36's pads in the upper left corner.
And here is the K2 assembled and ready for Integration Test 2.

I didn't wait an extra day this time; I plugged the K2 in and turned it on as soon as I was done with assembly (actually, did take a break to eat some lunch). I'm very happy to report that all tests and alignment procedures were well within spec and totally successful. I've spent the past day happily listening to CW and SSB on 40 meters, tweaking set up parameters, tweaking filters, and getting to know the rig. I'm planning to take another couple of days off and then get back to construction.

Happy days!