K1 - Really looking like a radio

After some more work on the RF Board, including winding a couple of transformers, I got to the point where I could attach the case sides, and plug in the front panel. Then I only needed to add a coax cable link on the back of the RF Board and it was time to power on and carry out initial testing and configuration. Everything went smoothly; sidetone works, the keyer works, I can change band! Next step is completing the VFO.

A bit of a break - CW keyer

I took some time out from the K1 to build a keyer interface cable, so that I can generate CW from my PC. The simple design (from Ralph WB8DQT) worked first time. I used a BF199 transistor and a 1N4001 diode instead of the components shown on Ralph's website.

After some off-air tests, I made my first 2-way-computer-assisted-CW QSO with 4N0NS, a special event station in Serbia.

K1 - Power applied and no smoke!

A few more short sessions on the RF Board and I reached the point where you apply power and test the voltage at a few points points on the board. Slight panic when the 12V bus tested OK but I couldn't get any of the lower voltage busses. I tried tracing the supply around the board with the help of the circuit diagram, and I came to a place where a link is supposed to be fitted but not yet. Then I noticed that I had marked up the manual with a pointer to the erratum sheet. Guess what, this added the step of adding the link before making the voltage tests :-) With the link in, everything was spot on. And no hot, smoking components, I'm glad to say.

K1 - First steps on the RF Board

It's been busy at work over the past week, so not much time for the K1. I have made a start on the RF Board. No problems so far, but lots of capacitors with very small markings. I'm glad that I have a digital meter for measuring capacitance and inductance (the L/C Meter IIB from AADE) as well as my old multimeter for resistance. It makes it quick to double check each component before I install it.


One of the early steps in making the RF Board is to check that the physical connections to the Front Panel and the Filter Board are OK. It was satisfying to have them plugged together, even if only briefly.

K1 - Looking like a radio

Today, I completed the Front Panel board and installed it behind the front panel. All went pretty smoothly. It was good to fit the control knobs and push button tops; no "life" in the K1 yet, but at least it looks like a radio :-)

I was left with three spare resistors. One was an alternative component from the backlight kit which I didn't need. But I'm not sure why I have the other two. I've checked twice and there are no unfilled component positions on the Front Panel board. One of the two resistors has a value that doesn't appear at all in the components list in the manual. And the other has the same value as four resistors that I'm sure I did fit correctly. Oh well, fingers crossed.

K1 - Filter Board finished and Front Panel started

Two or three sessions of toroid winding and the Filter Board is finished. I messed up one of the transformers with the interleaved windings; I had not pulled the first winding tight enough and I couldn't get the second one to sit properly. So I decided to strip off the wire and start afresh. Second time lucky!

The initial tests were all OK, so the board is now going back in its bag to wait for a later stage in the project.

I've made a start on the Front Panel PCB and the (optional) backlight kit for the LCD display. The Front Panel itself is the usual well designed (and well explained) Elecraft stuff. The backlight well explained but a bit fiddly to assemble, involving card, double-sided sticky foam and components soldered in mid air. I was glad when I installed the LCD and it fitted neatly over the backlight.

I have been combining K1 assembly with dabbling in the BARTG RTTY contest. More of both tomorrow, I hope.

K1 - Filter Board well underway

I have taken the plunge and, in three or four sittings, fitted the capacitors, crystals, relays, and first six (easiest) toroids. Instruction manual is very clear and well laid out. All going to plan, except that the recommended technique of melting the insulation off the toroid wire is just not working for me. So I have reverted to my usual technique of (very) gently scraping it off with a scalpel under a good light. Painful reminder, though, of the effect of passing years; reading glasses definitely essential for this kit :-)

Next step is the remainder of the toroids and a few other components, then fingers crossed for the initial test.

Starting on the K1

Way back in my first blog entry (now in the April 2006 archives) I mentioned that one of the projects on my to do list was an Elecraft K1 kit. Well, this weekend I made a start. It was the weekend of the Commonwealth Contest and I managed QSOs with two new countries, New Zealand and Antigua. So working CW for a few hours got me thinking about the K1 and I pulled the box off the shelf.

When the kit first arrived, I had checked the parts against the inventory. So "making a start" this weekend really just meant looking through the instruction manual again, realising that I was two capacitors short for the first module (the 4 Band Filter Board), discovering that I didn't have them in stock, and deciding that it was too late to go to my local Maplin to buy them :-) So I have cleared some space on my shack desk and dug out my antistatic mat and wrist strap. The real work will beging during the week once I have the missing parts.