Wednesday, March 20, 2019

Restoration of CAP Memories

The radios below belonged to a collection owned by Jopseph E. Headman. During the 1980s, Joseph and his wife and their son were, at one time or another, commanders of Civil Air Patrol Squadron 68 of Group 7 in the California Wing.

I had undertaken a restoration project in recognition of their service and hope to see that they will occupy a place where new senior members and cadets can get an idea of what CAP communications was like 35 years ago.

The pictures below are preliminary for review and editing.

Sunday, March 3, 2019

Testing the new tuner Too (two..whatevs)..

After assembling the 4 States antenna tuner kit, my overall impression was very favorable. Not 100 percent a fan of the kit aspect but about 98.7 percent. My only complaints are trivial: the pictures are somewhat ambiguous on some points and they trail the written instructions so you either pin up 3 sheets of pictures on your work area or leaf back and forth from instructions to the picture pages. Another complaint is that winding of the coil from the instructions is a tad confusing -- even including the pictures. And, thirdly, the polyvaricon caps received in the kit were festooned with connection tabs and it was not clear which tabs should be soldered where.

But these are truly petty gripes when offset by the final result. First, let me share what was learned.

One suspects the coil/switch assembly will be a toughie going in so it is well to prepare and study and prepare some more. Having a spare T106-2 on hand as well as a similar switch, I chose to wind a "practice" switch/inductor assembly for another tuner I am making. After a little struggle, it turned out pretty decently. However, the windings were the same for all twelve positions without the inductive "front loading" or "back loading" single-turn loops on the 4S tuner version. When I have some time, I shall ask why they do that.

Also, David, NM0S, points out that all but the three main tabs are not soldered to the board and can be cut off. In the hopes of clearing up a possible assembly ambiguity, here is the best picture from my build process that shows this.

That said, when I set out to test this, at first I had some difficulty getting it to tune my station antenna. It is a fan dipole for 40, 30, 20, 15, and 10 meters that somehow came together magically in the attic with decent SWRs on all of those bands. It's properties are that it presents a bitch of a time for the autotuners I possess on 17 and 12 meters. The internal K-2 tuner as well as the two LDG Z-11s on 17 or 12 meters have absolute fits! There have been a couple of manual MFJs and the QRPGuys tuner that were unable to obtain a match as well.

So that's the acid test. However, the 4State tuner handled it without breaking a sweat.

Once I got the hang of it, the unit was quite easy to obtain a decent match. The internal SWR bar graph on my FT-817 indicated that the radio was joyous over what it was seeing -- as did an inline Swan dual SWR meter. So, the little tuner will most likely accompany me across the way to the adjacent park and serve well with random long wires thrown up in the towering eucalyptus that abound there.

Anyway, here's some more shots of the resting process:

I just would like to add that it works wonderfully with my NorCal 40A radio. In the course of testing, I hooked up with a couple of folks using that rig and the tuner and got decent reports -- only to discover that I had left the VSWR bridge in line -- probably diminishing the output 990 mW a bit!

Friday, March 1, 2019

Yet another tuner..

Being an inveterate kit/project builder, I embarked on a line of tasks designed to familiarize myself with the practical aspects of tuners. You know, not the Smith Chart and algebraic type of analysis that are the underpinnings of devices but rather the "hands on" efforts that cement the dry prose and formulae into real items.

Such are tuners.

I have walked back from the concept of EFHW transformers and their ilk to the devices that will resonate anything -- from a long piece of wire to a mayonnaise jar -- on bands as low as 160 meters. Though, to be honest, I see little value in any tuner being used above 20 MHz. I mean, six feet of wire on the side of a loop or as one half of a dipole is perfectly manageable -- even on my small patch of ground.

Anyway, I dealt the QRPGuys tuner off to a gentleman on the other coast (as I recall) and was casting about where to turn next. Rummaging through my vast heap of stuff, I discovered that I had the makings of some really, really world class antenna matching devices. These consisted of a robust pile of the old AirDux coils garnered from an old Tuthill swap many years ago, a king's ransom in air variable caps, and God's own assortment of toroids -- including the common "-2" and "-6" types to to the more exotic "-37" and "-61" guys. Also, I had laid in a goodly supply of cardboard tubes from my bride's outgassing of Saran Wrap which are handsomely suitable for coil forms. But I blather. I will do more as I embark on a home-built device further down the road.

The QRPGuys' tuner was a nice unit but it's case was "too open" and I feared any outdoor operation would have been set upon by dirt, insects, bird poop and errant pine cones. Looking around, I caught site of the 4States 4S Tuner kit and thought to build one of those up.

I will provide more background and my opinion of the kit in a subsequent post but, for the time being, here is a small collection of my build photos.

Basic "outboxing" of the parts and a partially built case..

Intermediate build photos..

..and a few snaps of the pre-test results..

Back in a jiffy with a build-and-test report.