Very, Very Small . . . Verrry Smallll!

I have gotten to the point where I am so old I can't remember when I started getting all the physical symptoms of getting old. But somewhere in the last century or so I came down with what the medicos call, among other things, "essential tremor."
     My hands shake. Sometimes real bad. Usually when I have a dangerous tool like a knife or a soldering iron or a drill in my mitt. Makes soldering tiny parts a real pain in the tuchus.
     At any rate, even before I discovered this shaking thing, I had a distinct aversion to surface mount stuff. It was just too damn tiny and, with my propensity to drop things for no apparent reason (also part of the tremor thingie), I just didn't feel all that much good about trying to build stuff using SMD. Surface mount devices.
     Of all the things I've built over the past twenty-odd years of living at this rendition of the estancia, I can't think of but one or two things that had SMD on 'em and all of them, all two of 'em, were a pain in the ass. Stuff that I thought was spiffy would be thought better of if I discovered in the process of research that there was SMD solderin' going on in the process of building.
     Things that had standard, thru-the-hole-on-the-board part placement & construction were preferred.
     And once the shaking started, none of it was fun any more.
     I thus at first limited myself to building things that had no more than 20 parts. Voltage regulators. Charge controllers. SWR bridges. Direct conversion receivers. Stuff like that. Ten, maybe twenty parts max. And no SMD.
     The only time I fell of that wagon was in buying and building up to the part of putting a box together for it a SW40 from Dave Benson. And the PFR-3 that I bought from Doug Hendricks last year at Dayton, which is another story after this one.

So last summer I take the FT817ND that my eldest gave me for Christmas the year before and a bunch of other claptrap down to the beach house for a week of relaxation and Corona-by-the-pool drinking. I took along an Elecraft T1 auto tuner, which I had successfully built and then subsequently blew up. And I took an LDG auto tuner that survived the madness very nicely, thank you very much.
     But I realized almost immediately that I'd have been better off bringing the home-brew Z-match tuner that had served me well for many years prior.
     Only problem was the size of that version of the Z-match. It barely fit in the bag when I had only a K2 and there weren't no room for it in the bag that I had gotten for the '817. (Which bag, by the way – and we're talkin' of the '817 here – is a Maxpedition Sabercat Versipack [$109.99 from Lapolicegear.com].)
     Upon getting home from the beach, I began investigating my options.
     I didn't really want to build another damn tuner, so I sprang the cash for a MiracleAntenna QPack Precision tuner, as noted in a previous and boring entry of this blog.

Upon getting the QPack Precision, I still needed a SWR bridge. And my previous experience with SWR metering had proven many times that a simple LED is a lot more rugged and a damn sight easier to figure out than a mechanical meter movement. Thus I searched up a couple version of the N7VE/Dan Tayloe SWR bridge and found two simpler version of the circuit, the last of which had one part less than the first.
     So I sprung for $60 worth of circuit boards and built a little bridge to fit inside the QPack Precision.
     It woiked great.
     I could sit under the backyard chestnut tree with my '817 back-and-go station and play radio from 75m through 6m. All I had to do was flip the appropriate switches on the tuner and tune the appropriate LED to the appropriate darkness. And there was a lot o' switches, yo.
     
Are you waiting for the "But then . . . "?

Well, then I started thinking about how small the QPack Precision was compared to the Z-match and that got me looking for a box like the QPack box, which led me to the Hammond 1445 series extruded aluminum boxes, which led me to building anew another version of the first Z-match tuner, which led to a discovery.

One of the reasons that QRP loonies can get away with the simple circuits and the low grade components that they often use in very creative ways is the low power levels at which they play. There is a huge difference in building a resistive network for five Watts versus building one for 100 W. In a resistive bridge the usual deal is to run two Watt resistors for a five Watt tuning bridge. Try that with 100 W and you get smoke in da room, yo.
     The streets is real, man.
     Recent technology has led to the availability of what looks like a five Watt non-inductive resistor which in fact is really quite inductive under that pretty twenty-first century covering.
     But recent technology had led to the development of so-called "thick film" resistors, some of which are monstrously sturdy for their size.
     A 100W, non-inductive, thick-film resistor is now available in a TO-247 case.
     Seriously.
     But you need a heat sink.
     In the mean time, there are now SMD, non-inductive resistors that come in 10W and 20W ratings. They're about the size of an unused clump of kitty litter.
     Seriously.
     But you need steady hands to play with 'em.
     I know 'cause I have messed with six of 'em so far and the results have been, well, tiny. And they cost about $6 each. That's a trade-off.

The rebuilt Z-match has a tiny SWR bridge in it using three Bourns SMD chip resistors and a couple thru-hole parts on a board ain't much over .5x.875". The switch solders right to the edge of the board and the LED stands off it a few inches inside the box.
     And it works.

Only thing is, I now have about 30 tiny little circuit boards for which I could take the time and buy enough of the little resistors to build 30 of the little bridges which I could then sell off to recoup the money spent on getting the boards done.
     I could if I was nuts.
     But I have intervention now and they won't let me solder that much crap. Not even stretched out over a couple months, like's been the case with the PRF3.
     Nope. I'm done.
     I have tasted the waters of SMD and I have found them, well, frustrating has hell. Between the hands wandering around in spasms of joy and indelicacy and the family getting tired of my cussin' and the parts flyin' around in all directions with the cats immediately taking interest in them in flight or on the ground, I've had enough.
     I'll leave the SMD work up to younger hands and eyes than mine.
     The next SWR bridge I build will use those big sucker resistors.
     And a meter. A big meter with large numbers that I'll be able to see from across the yard. Yeah, from across the yard. Like a goddamn scoreboard.

That's the ticket!