Favorite Things–Part 2

OK, this time, more things and fewer words. Very unlike me, I know. Let’s declare a theme for most of these items–soldering. If that’s not interesting to you, I’ve saved you some reading! Do at least have a look at the office chair wheels towards the end of the list, though, if you have a wheeled chair in your shack or home office. There, more reading avoided if not!

  • Organizer boxes for small parts. I have lots of small electronic parts. For some, I use the slide-out drawer-type storage compartments that mount on a wall. And I have quite a few of these, but for certain items like small SMD surface-mount “chip” parts, I need smaller compartments that I can move around, and that do not spill the little parts if dropped or turned upside down. I bought a couple of these recently, and they fit the bill nicely. They won’t spill things, can be easily re-configured for larger or smaller compartments, and generally look to be good quality for the price, which is $10.99 each. By the way, they are the soft-feeling plastic, not the hard, brittle type. Since they are “just” plastic, I would avoid putting anything in them that could be damaged by static electricity.
  • If you do much soldering or building, or need to repair soldered pc boards on occasion, here is a very inexpensive hot-air soldering and rework station. Price is an unbeatable $75.99 for everything, including various sizes of hot air tips. If you’ve never used hot air for de-soldering an SMD part, you’re in for a treat. Hot air can also be used to solder, if you’re careful. Be sure to keep the temperature high, the air tip small, and the airflow low. You don’t want to blow other components out of place. Been there, done that. It’s not rocket science, though. Just be aware of that little issue. Doing SMD repairs with this gadget (along with the liquid flux mentioned next) will save your sanity.
  • If you’ve ever done any soldering, this may not be something you’ve had any experience with before. That’s because many people don’t understand the need for soldering flux, but I swear by this little bottle. It’s helped me do so many otherwise difficult (or semi-impossible) soldering jobs with SMD components. Without going into a chemistry lecture, let me simply say that it makes the parts you want to solder together more attractive to solder. It gets rid of the surface tension or oxide that sometimes causes the solder you’re applying to ball up or just drop off the part, rather than melting nicely to it. For SMD parts, I literally drown the little chips in this flux (you can drown them with a single drop), and they just magically adhere to whatever you’re trying to get them to stick to. It does this by its mildly-acidic nature, stripping oxide off of copper or tin pads or wires, and then keeping oxide-causing air away while you solder the parts. Another bit of goodness is that this is genuine Kester soldering flux. Kester has always been a big name in solder and soldering chemicals. This little 2 oz bottle is $13.18 with the usual free shipping, and it will likely last you the rest of your life, unless you do as much soldering as I do. I’m on my second bottle. Highly recommended for soldering even big parts together, and the little needle-like applicator helps you by doling it out at just a drop at a time. Many times you’ll only need one drop.
  • After you’ve soldered something, especially if you used flux, this next item is a nice-to-have near your soldering station. It’s an alcohol pump dispenser for $9.90. You grab a cotton swab or Q-Tip, tap the top of the dispenser with it, and a little bit of alcohol soaks it. You can then swab the solder joint or pc board to get rid of flux or just for general cleaning. This is almost mandatory to do if you are using high-impedance (and static-sensitive) devices, such as MOSFET’s, CMOS microprocessors, etc. The left-over flux can attract dirt and dust, and eventually form a low-resistance short between two points you didn’t intended to have shorted to each other. This scenario is most likely when you are working on a printed circuit board, rather than freehand soldering of, say, two wires together. At work, we have one of these pumps and some cotton-tipped sticks at each soldering station. Good stuff, and you avoid having a constant alcohol-ish smell in the lab.
  • Keeping with the soldering theme, you should clean the tip of your soldering iron often, ideally each time you solder a single joint or part. If that seems excessive or OCD to you, let me assure you that it’s not. As soon as you finish soldering a connection, the remaining solder or metal on the tip of your iron starts to oxidize. That layer of oxide will act as an insulator when you go to solder your next part, making it seem like your iron temperature has gone down, often significantly. It also makes it very hard to tin your tip with a little solder, which you should do before soldering a new connection. To keep oxidation of the tip from happening, many people, including me sometimes, use a wet sponge. Wiping the tip with a damp sponge helps keep the tip nice and shiny, but also wipes away any solder still remaining, and that isn’t always what you want. This next item solves the tip preparation problem by giving you a small, bottlecap-sized container of tin and ammonia for only $6.35. I hot-melt glued mine to my soldering iron holder, and I just rub the tip on it briefly before starting a new solder joint. It’s texture is hard, but just a bit of it melts on to your iron with each application. It cleans the tip of oxide, and adds back a little tin to “tin” your iron each time. As you probably know, solder is mostly made of tin, lead, and a little flux. At least, it used to be that solder was tin/lead. Now we have lead-free solder, which I can tell you from experience is mostly horrible stuff. It has a wetting (adhesion) problem. Thank goodness you can still buy the good ol’ 60/40 or 63/37 tin/lead solder. The link is for a one-pound roll of the best solder on the planet for just $27.28. A pound will last you a long time. Regarding the worldwide lead-free rules, it’s true that we have to use it in electronics manufacturing, yes, but not for hobby or lab use, thankfully. Wash your hands after a soldering session, though.

  • Speaking of soldering, there are other ways to hold things in place. In the past I’ve used the white foam double-stick tape for mounting various small objects, as I’m sure you probably have. I’ve always thought that there should be something better. Something with more grip. Something permanent. And then I noticed that our little WiFi modules were mounted to some TV chassis with this interesting black tape that really stuck them in place. They were definitely not going anywhere with this tape on them. Trust 3M to have developed Scotch VHB tape for this purpose. VHB stands for Very High Bond, I think. You can stick just about anything to just about anything else! Here is a 1 inch by 15 foot roll of it for $17.99. Very good stuff. It has some thickness to it like the white foam stuff. Just make sure you really want to stick something in place before you, well, stick it in place. Makes the white foam tape look sad and anemic.
  • You might find this next one a bit strange, considering the electronics theme we’re on, but let’s say that this might improve your soldering by giving you better mobility and keeping static electricity down a bit. I’m talking about replacing the little plastic casters on your wheeled office chair with these very useful replacement urethane wheels made for office chairs. They are $38.95 and worth it. They work way better on many carpets than those little hard plastic casters, and eliminate the need for those awful plastic carpet protectors. Here in the mountains of Utah, carpet protectors are HUGE static electricity generators. I can sit down on one, move a foot or roll the chair a bit, and draw a 1/4″ spark off of anything I touch. You can actually get anti-static carpet mats, but they cost 2X-3X or more. Anyway, these wheels roll way easier, don’t get fouled up in things as much, and have way less rolling resistance. They are made to fit the (almost) universal rod and lock ring found on most office chairs. And there are 5 of them, which I didn’t realize is a very common number of legs on wheeled office chairs. I popped out my old ones and put these in with no tools in under 5 minutes. Whee! Now I can really roll–I love them! The only downside, and it’s minor, is that they make the chair seat about 1″ taller. If you have your chair lowered all the way down like I do, that might be an issue. It actually is for me. I’m 6’1″ tall, but I’m about 6’7″ from the waist up (and I’m only a 31″ inseam–I think they call it being over-square or something). So I sit tall, so to speak. People in my office who occupy a conference room after me always know where Dave sat–their eyes are sometimes level with the tabletop! Anyway…try these on your next chair–you’ll be surprised.
  • Since my theme seems to be soldering-related, and I’ve just mentioned static electricity, here’s one that tries to help one by eliminating the other. It’s an 18 by 30 inch anti-static mat that is made specifically to withstand direct assaults by soldering irons and hot solder. It sells for $57.50. I have several of these, and they work quite well. They also give you a consistently-colored, flat surface to look for small SMD parts you might have just dropped. At my work, even though it’s in Northern California, we make extensive use of anti-static mats, wrist straps, and even anti-static floors, and chairs with little metal chains that droop down to make constant contact with the floor. Even if you don’t feel a jolt, static electricity can and does pass between you and anything you touch. I seem to recall that we have a threshold of feeling that’s somewhere around 5 thousand volts. Anything less may go unnoticed by people, and at the same time, blow out the junction on a MOSFET. We also practice the “touch me before you hand me the pc board” protocol to dissipate these lower-level jolts (much harder to do now with social distancing). Anyway, these are good mats. Remember to ground them to the screw on your AC wall plate or a similar electrical ground spot.

OK, so that’s it for now. I’ll try and add more soon. The young lady in the Prime van said to tell you hi, and that she misses her family.

Dave – K7DAA

Winter Field Day 2020

Come join us January 25th for the 2020 Winter Field Day. We will be at Christmas Hill Park in Gilroy all that way at the back of the park where we usually set up for the June Field Day. It will be a fairly relaxed day. – No towers, trailers, mostly go-boxes and portable HF antennas. Come as you are. Ask as many questions as you want. Stay as long as you like. Set-up begins around 9AM. Transmission begins at 11 AM PST. We will stay as long as we feel like it. See the link below for details and operating rules.

https://www.winterfieldday.com/

Gilroy Maker Faire 2020

So how cool would this be? An opportunity to highlight our hobby, and its roots in making, in our own back yard! Be prepared to be peppered with suggestions of our local clubs getting a booth together. Maybe we can even do a balloon launch, some on-the-air demos, DMR, some remote control, how repeaters work, and even drum up some folks for a ham-cram.

Polar Explorer

Here is an interesting find from 2019 Dayton Hamvention, the Polar Explorer. It is a 500 watt transmitter that mates with your existing radio. It is not an amplifier. It is a self contained 160-10m transmitter. It is currently still a work in progress, and the developer has been working on the design for the past 6 years. There is no receiver in this design. You use your existing transceiver. There is a short survey you can take on the page, and even sign up to be a beta tester. Check out the deets on www.polex-tech.com

Monthly Electronics Flea Market @ Fry’s

Some of you I’m sure know about the Bay Area Electronics Flea Market. It used to be every month, starting in the spring, through the end of summer, in the De Anza College parking lot.

In 2018 the market moved to the Fry’s in Sunnyvale. A wide assortment of all matter of electronic doo-dads, thingamabobs, and widgets of all shape and size are often present. If you ever want to see a walking history of electronics in Silicon Valley, that alone is worth the visit.

Check it out some time. For times and dates check out their website!

YT-450 Upgrade? Yup!

My first HF radio was a Yaesu FT-450D. Like many radios with an internal tuner, it was limited to 3:1 SWR matching. Since I was using a G5RV Jr for an antenna at the time, this was not quite enough to properly tune across 40 meters. 80 meters was out of the question. A local ham had some gear from an SK that was needing a new home and one of the items was an LDG YT-450 external tuner, made to be paired with the 450D. It was also made to be used with the FT-950 which is how it was being used. It was the right time at the right price, so I purchased it. It worked great with the 450D. But, about a year later I sold the FT-450D and upgraded to the newer FT-991. The YT-450 did work with the 991! For a while…

A Yaesu firmware upgrade put an end to that, and it stopped working. And that is where I was stuck for a while. I had changed to a fan dipole, and later to an OCF dipole. So 3:1 matching was again within my reach, although on 40 or 80 meters I would get weird SWR sometimes.

I was getting ready to move some things around in my go-box and was staring a the YT-450 thinking of just removing it, selling it, and purchasing a YT-1200 which is compatible with the FT-991. It is nice to have the wider range tuner because we sometimes want to use an end-fed, or random wire, and so a good external tuner can really come in handy. So I hit the Interwebs to find a deal and ‘lo and behold…

I came across a chip upgrade on CheapHams.com that replaces the ROM with a new ROM that makes the YT-450 essentially a YT-1200, which restores compatibility with the FT-991! For $20, they send you chip and a sheet of instructions for installing the chip, and the parameters to set on the FT-991. 4 small screws and 10 minutes later and… Done! I have a working tuner again… for $20!