Which Coax Did I Want Again?

How many ways is this question asked and answered? There are a gazillion articles on the topic. I have been reading. A lot. And here is what I have come to find…

Most of my coax has been RG8X, across the board. I didn’t really know much better, it is exceptionally cheap, and as far as I can tell, my signal is leaving my radio and exiting out through the antenna. So what have I learned…

For the average home amateur radio operator there are more options than just RG8x and LMR400. I know! Blasphemy! Like 90% of the conversations revolve around those 2, unless you are doing repeater work with the club and someone mentions Heliax or hardline. Well guess what. You should add a couple more.

RG-213 – Sort of the little brother of LMR-400 for HF. About 1/3 less loss than RG8X. But… if you are even remotely thinking about any kind of amplifier in the future, then RG-213 may be the cable you are looking for. Where RG8X is only good for around 400 watts in the HF bands, RG-213 can handle over 1,200 watts, easily. Is not as large and bulky as LMR-400, but is certainly larger than RG8X.

LMR-240 – Never heard of this before? If you are running portable, or insist on running RG8X, then you should also be considering LMR-240 and LMR240-UF. The “UF” is for ultra-flexible. With a 35% or better loss advantage over RG8X, in nearly the same diameter and flexibility, with almost 3 times the power handling, LMR-240 is a drop in, high quality replacement to RG8X. LMR-240 is also sort of in a sweet spot where for shorter runs, it also works well enough for UHF/VHF. For your Go-Kit cables, or field day setup, LMR-240 is a great option. I just used ABR Industries to order several LMR-240 cables and can’t wait to try them out. I will do a review in the near future.

Check out the stats here: https://www.universal-radio.com/catalog/cable/coaxperf.html

Spider Antenna – Circa 1985

On the heels of the Wolf River Coil DIY tripod rebuild, comes the Spider Antenna. Invented and patented at the time by Fred Smitka, K6AQI, out of California, the Spider Antenna was created and sold in the early 80’s. It is by design a mobile antenna designed to take advantage of the ground plane a vehicle can provide. But since I had just reworked my tripod for the WRC, I made a few adjustments so that I could also connect the Spider Antenna and take advantage of the radials I had already created for the WRC. And it works! Sort of. More on that in a moment…

Where the WRC is a bottom loaded vertical, the Spider Antenna is a top loaded vertical. This blast from the past was picked up in a Craigslist buy several years ago. I was looking to upgrade a dipole from my then G5RV Jr. When I arrived to purchase a DC-CC fan dipole I was greeted with a pile of various antennas. There were a couple of wire dipoles, a rigid Cushcraft D3 20-15-10 rotatable dipole, what looked like at least a pair of “chimney sweep” MFJ antennas with all manner of missing parts, and maybe one other antenna worth of parts I never did figure out. But, there was also a cardboard tube that contained this odd looking antenna system that is known as a Spider Antenna. The seller was more than happy to see the entire pile leave. Their trash became my treasure.

So what is this thing? In simple terms, the Spider antenna is a top loaded vertical. Unlike the coil antennas we are accustomed to seeing, where you have 1 coil, and then you tap the coil for the band you wish to operate on, the Spider Antenna has a 5′ metal mast, with a fitting at the top for up to 4 individual coils. There is a separate coil for each band. The coils come in bands 80-10. The one catch is that 80, and 40, can only go on top. So you cannot for instance have 40 and 80 on at the same time. But you could do 40, 20, 17, and 15 if you like, or whatever combo you wish. What was really cool about this find was that it was a complete set of coils for 80-10 meters. bands!

To tune the antenna, over each coil is a ferrite that you slide up or down the coil until it is resonant where you want it within the band. As the bandwidth can be a bit narrow on 40/80, you will have to adjust to which end of the band. What is also remarkable is that after 36 years, this antenna still seems just fine. The antenna is rated to easily be able to handle 200 watts. And I even found a review online from Gordan West that claims he ran a Magnus 800 watt amplifier through the Spider Antenna and it worked just fine.

The entire antenna is of quite high quality construction. Normally, as we have experienced, plastic coatings break down over time. The materials on the Spider Antenna have held up very well. Each coil is of rigid fiberglass construction.

Setting it up in the back yard and using my Nano VNA, I was able to bring adjust each coil in just a few minutes. I hooked up my KX3, but was only on battery so output power was quite low, but I was able to receive quite well. I will have to connect to the TS-440 and do an A/B test and post an update.

QRZ.COM New Logging!

Have you checked out QRZ.Com’s logging features lately? They have come a long way in the past year or so. Did you know you already have an account as an amateur radio licensee on QRZ.com? Well you do! You should check it out. Create your logon, and there are all kinds of goodies there from current news, forums for sharing tips, discussing new hardware, and even a swap meet for selling new and used equipment. There are always interesting things to read.

But what has truly improved over the past about 18 months is their logging feature. I now pretty much do all my logging directly into QRZ. Even with things like FT8, I have the software set up to directly send the log update into my QRZ log. I also have my LOTW set up so with 3 clicks of the mouse, I can upload all my current session QSO’s to LOTW, and then a couple days later, with 3 more mouse clicks, retrieve all my LOTW confirmed contacts. You should really check it out!

Look Ma! I’m on Facebook!

I finally took some time to straighten out the social media plugins and made some changes on the Facebook accounts. The interaction systems are kind of convoluted. For instance, you cannot just syndicate to Facebook groups. There are “steps” and they typically are not free. But you can syndicate to a page. So the After the Net Facebook group is being retired. And there is now an After the Net page instead. So be sure to stop by and hit the “Liked” button so you get updates in your feed. Articles written and published here will also automatically now be posted to the FB page. So we can use this format for longer how-to’s, reviews, and other technical discussions, but still promote to a wider audience on Facebook.

I will try to keep things here more up to date, and also to take advantage of the scheduling capabilities to space things out a bit. But If you would like to contribute to our local amateur radio community and write articles or share other information, please contact me. We can get you set up with authoring access!

Ray – N6DZK

Son of “LancePod”

A couple years ago now, our local craft person, Jonathon, W6BID put together a club build for a tripod for the Wolf River Coils SB1000. The WRC TIA (Take It Along) kit t is an excellent, economical, portable, base loaded, vertical for pretty much any band. The community around this antenna has spawned all manner of modifications, whip options, radial options, and in this case a DIY tripod. The “out of the box” tripod, while mostly adequate, was tippy in windy conditions. Several of us have also adopted either the MFJ-1979 or Chameleon SS-17 stainless steel whips for better performance on the lower bands. The problem being with the longer, larger whip, the base needs more stability. Enter W6BID…

For a club meet, W6BID organized kits for us to assemble in a weekend garage project. Each of us taking turns drilling holes, and assembling our new WRC tripods. The original kit consisted of a piece of plate steel, a 3/8″ thru-hole, stainless steel antenna mount, 6 L brackets that Jonathon had welded to the plate ahead of time, 3 sections of 1/2″ steel square tubing, and some bolts here and there. All that and a quick coat of spray paint resulted in one stout tripod base. It has served us well!

But some issues crept in over time and after multiple uses. For starters, this thing is chonky! And secondarily, since the plate is steel, oxidation formed in between the plate and the stainless steel antenna mount creating resistance with the radials. This was finally identified as to why SWR readings were so out of whack from when the last time it was used.

So back in the shop it went for an update.

To address the chonk, I drilled holes down each of the 3 legs at 3/4″ intervals, and then turned the leg 90 degrees, and repeated at offset 3/4″ intervals. The end caps which had fallen off long ago, were replaced, but this time filled with hot glue before being re-attached. The base metal plate also had large holes drilled where I could safely remove material. This reduced the weight considerably, but still providing a solid stable base for the antenna.

To solve the oxidation issue I used a product called DeoxIT L260Cp that is a lithium grease that is infused with copper particles. Once the steel surface was cleaned back down to bare metal, a dap was applied to the surface and everything reassembled. Other changes made along the way…

  • Much experimentation with radials
    • Out of the box are 3 33′ radials made of black silicone coated wire.
      • Pro – Fairly quick to roll out.
      • Con – Performance was “Ok”.
    • Doubled to 6 33′ radials
      • Pro – Increased performance significantly
      • Con – When out in the field, you are taking up a circle nearly 70′ across. When camping this is valuable site space. The black wire was hard to see in the grass. Gopher/ground hogs actually tried to drag radials down one of their holes one night at a camp site.
    • Swapped out wire radials for 33′ tape measures
      • Pro – Fast to deploy. Easy to change the length if you want to “tune” the length for the band. Super fast to roll back up. Bright yellow tape is easy to see when deployed so people are less likely to walk through your radials.
      • Con – They rust. They are heavy. They are bulky.
    • Swapped out tape measures for 9 8′ radials constructed from a bright yellow silicone wire, and added quick disconnects.
      • Pro – Very fast to deploy. Bright yellow for visibility when camping or portable. Shorter length is way way less prone to tangling. Very lightweight. Compact. Works just as well as the 6 33′ radials.
      • Con – Not quite as efficient on 40 or 80 meters, but is still below 2:1.

Overall this has been a great project that has now gone through a couple iterations resulting in a very portable HF antenna solution that has performed exceptionally well. I just recently also picked up a padded tripod bag to store it in, and have a 50′ length of ABR Industies ABR240-UF (Ultra Flexible), with 5 ferrite beads shrink wrapped to the end. This entire solution can be in place in moments, is easy to tune, and with the larger SS17 whip is an efficient antenna system.

The Quality Triangle…

The axiom is that you can only ever pick one of 3 sides. Which means you can only achieve 2 of the 3 choices. I’m okay with that. But an interesting facet of amateur radio (and probably many hobbies) is the quality triangle does not apply. You can can spend a lot of money, on low quality hardware, over an extended period of time. You can also very quickly get quality hardware, on a decent budget, at swap meets, through club swaps, and sites like QRZ, Craigslist, and what seems to be the new king is Facebook Marketplace. Bend the quality triangle to your own will.

Just When You Thought Things Couldn’t Get Any More Weird…


The Radioddity GA-510, dual band, 3 power level, handheld receiver, manufactured by Baofeng, was just reviewed in QST magazine. A Baofeng! In QST! I know! Hell hath truly frozen over.

The QST, December, 2020, review (ARRL logon required to view) gave details about performance, features, and price point, which were all given high marks. Listed as an 8 / 4 / 1.1 watt selectable HT, the radio reportedly has a solid front end, good sensitivity, and harmonic suppression apparently suitable to warrant a QST review! And at $65, it is very competitive with many of the other “lessor” models in the lower end of the amateur radio market. The programming is typical Baofeng, but it does come with the programming cable, in the box, as well as belt clip, wrist strap (Does anyone use these?), and an earpiece/mic combo unit. The radio is also bundled with 2 – 2,200 mAh batteries that should provide significant run time. The number of memory channels is still restricted to 128, per Baofeng tradition.

Overall, it was a solid review and worth taking a look?

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