WB4SON

I’d say this is about 1/6 of the work (2/6 for the Front Panel, and 3/6 for the RF board remaining).  It took a total of 255 minutes to complete the installation of 64 component, or about 4 minutes per part (that would put the total assembly time for the K1 at about 25 hours).  That includes all of the final assembly tests (resistance, shorts, opens, correct placement, etc.) as well as quite a bit of time spent with the toroids (especially the incorrect diameter parts).

Things were going swimmingly with the K1 Filter Board assembly, still at a rate of 1 component per 3 minutes (I follow a 7-step process:  check value, check value, install, check value, solder, check value, check solder).  Then I hit a snag…

When you order the K1, you select which two bands you would like.  I picked 30m and 20m, two of my favorite CW bands.  I had done a careful inventory of all parts and found them all there.  However, the Bill of Material didn’t specify the toroid size, just the color.  I had two T50-6 cores with the 30m kit, and two T37-6 cores with the 20m kit.

When I got to the assembly instructions for the 30m L9 and L10 toroids, I found they should have been on a T37-6 core too — the cores I had were a bit larger.  The desired inductance (1 uH) was known, specified at 18 turns on a T37-6 core.  I verified that, then reran the calculations using a T50-6 core, and found it would require 16 turns to maintain the 1 uH value.  I then called Richard at Elecraft and asked his opinion — “no problem, use the T50 cores and just take a turn off”, was his advice — so 17 Turns it will be.

The only down-side I see is that the T50 cores, being a bit larger, put L9/L10 a bit closer, and it is possible there might be an issue with the automatic antenna tuner since the toroid stands tall.  However it is exactly the same height as the slug-tuned inductors in their metal cans, so surely the board spacing will be adequate to clear both.  Besides, at the moment I have no plan on using the internal tunger since I have several external ones.

Needless to say, I verified the diameter of every other toroid in the kit.  Fortunately they appear to be correct.

Putting together a Doppler antenna switch for fox hunting (Handi-Finder) reminded me how fun making things can be.  It’s been many years since I’ve built a radio kit, and I’ve been itching to feel that “glow” you get when you make something yourself.

I decided to purchase an Elecraft K1 Kit for 30 and 20 meters (sadly the four band module is no longer available, so I was forced to pick only two CW bands — I’m going to miss 40 and 17 for sure).  Unlike current Elecraft “kits” which are nothing more than a mechanical assembly of pre-fabricated and tested circuit boards, the K1 is a “full kit”.  The user needs to solder all the components, fabricate the toroids, do alignment, and complete the mechanical assembly.  I’ve read that it takes about 24 hours to complete.

I spent about 3.5 hours inventorying every part and found everything there, including a few spare fasteners in case some got lost.  My only frustration with the inventory process was that some of the capacitors are almost impossible to read due to nearly invisible laser etching/printing.  As you can see from the photo below, there is quite a collection of parts (302 electrical, 127 mechanical, and 10 toroids to be wound) that will eventually find themselves onto three PCBs (Front Panel, RF, and Filter Board).

Those nasty caps came into play immediately as the first board to be assembled was the Filter Board.  So far, I’ve spent about 1.25 hours assembling the 30 meter band parts (less toroids, which are installed later).  So far that’s 24 parts in 75 minutes, or just about 3 min. a part.  At that rate I’ll need 900 minutes or 15 hours for the electronics and another 6 hours for the mechanical stuff — just about 24 hours total with the inventory time. Hopefully winding the toroids won’t skew that number too much.  My progress so far is shown in the photo below.

I must be a real New England Patriots fan as I’m going to watch their game against Denver rather than doing more assembly tonight.