Equipment – Page 5 – WB3GCK QRP Amateur Radio

The Splice of Shame

[Disclaimer: Any misadventures I have had with this antenna were purely my fault and, in no way, reflect on LNR and their excellent product.]

I bought the LNR EFT-10/20/40 trail-friendly end-fed halfwave (EFHW) antenna about a year and a half ago, after seeing one at Field Day. It’s a great, portable antenna. It packs up small and weighs hardly anything. I often use non-resonant antennas because I like to work a variety of bands. However, I always carry the LNR end-fed in my pack as a backup antenna. The EFT requires some initial pruning before use. This is where my misadventures start.

I don’t have enough real estate at home for antenna testing. Instead, I did the initial pruning of the antenna while setting up for the Skeeter Hunt QRP contest in August of 2015. Trimming an inch at a time was getting a little tedious for me. I incorrectly estimated how much I needed to cut to have the antenna favor the CW section of 40 meters. As you might guess, I screwed up and cut off too much. Resonance was at about 7.110 MHz and frequencies below 7.023 MHz were outside the 2:1 SWR curve. 20 and 10 meters were fine, however. I operated in the contest with no issues.

I resolved to correct my mistake and added that task to my “job jar,” where it languished for the next year and a half. In the meantime, the antenna was used for numerous outings, including a National Parks on the Air (NPOTA) activation of the Appalachian Trail. I just needed to avoid the bottom end of 40 meters.

Fast-forward to this past weekend. I finally got around to doing something about the tuning of this antenna. I had ordered some #26 Poly-STEALTH™ wire from the good folks at Davis RF. First, I measured the top section of the antenna (from the top of the loading coil to the end of the antenna) in its current state. Then I cut the wire about a foot or more from the end. Since the splice wouldn’t fit through the holes in the end insulator, I wanted to keep the splice away from it. I did this if I would ever want to re-tune the antenna for the phone section of 40 meters. I next spliced on a piece of Poly-STEALTH™ wire that made the overall length about 2.5 inches longer than before. After soldering the splice and applying some shrink tubing, I was ready to give it a test in the field.

The Splice of Shame. This is the splice I had to put onto my LNR EFT-10/20/40 EFHW antenna to correct my pruning error. — The Splice of Shame

I was out in central Pennsylvania over the weekend doing some babysitting for my grandson. As I have done at this location before, I strung the EFT-10/20/40 from a second story window to a Jackite pole strapped to the fence in the backyard. The antenna was roughly horizontal and up about 25 feet or so. I wanted to make sure that the range from 7.000 MHz to 7.125 MHz fell within the 2:1 SWR bandwidth. My antenna analyzer showed that it was just a bit long.

After I lowered the antenna and cut off a half-inch, the SWR was pretty much where I wanted it. Now it was resonant around 7.040 MHz and the 2:1 SWR bandwidth spanned 7.000 to 7.130 MHz. On 20 meters, the SWR was less than 1.5:1 across the band. On 10 meters, the SWR was less than 2:1 across the band. The SWR indicator on my KX3 confirmed the results.

Final 40M SWR plot for my LNR EFT-10/20/40 antenna. The 2:1 SWR curve covers 7.000 through 7.130 MHz.

At one point, my inner obsessive-compulsive perfectionist said I could cut off another half-inch and make it better. Fortunately, my practical side was able to resist and leave well enough alone. As they say, perfect is the enemy of the good. So, I declared victory and went on to make some nice CW and PSK-31 contacts with my properly tuned antenna.

The antenna works great but that splice will be a constant reminder of what happens when you rush things and try to cut corners.

72, Craig WB3GCK

The WB3GCK Downspout Antenna Revisited

[A ham friend of mine recently asked me for the details of how I use my rain gutter and downspout as an antenna. I originally did a write-up on it in 1994. That article found its way into several ham radio publications and newsletters. Most of the original article is still relevant but I have made some changes in the way I feed the “antenna.” So, here’s an updated description of my Downspout Antenna. – WB3GCK]

After years of trying to come up with a good way to get on the HF bands from my little townhouse (without attracting a lot of attention from my neighbors), I started experimenting with using my aluminum rain gutter and downspout for an antenna. The results have been surprisingly good. In fact, it has turned out to be the ultimate low-profile antenna!

The downspout has a vertical run of about 16 feet, connecting the horizontal rain gutter which is about 16 feet long across the front of the house. Including the feed wire into the shack, the total length is in the neighborhood of 42 feet; over a quarter wavelength for 40 meters and almost a half-wave for 30 meters. The house is made of brick, so the entire system is isolated from ground.

Diagram of the WB3GCK Downspout Antenna — WB3GCK Downspout Antenna

I use my downspout like a random wire antenna, using a commercial autotuner (or internal tuner, in the case of my KX3). I feed the antenna through a homebrew 1:1 unun. I use a short run of coax between the unun and the autotuner on my operating table. A length of #22 stranded hookup wire is used to connect the output of the unun to the downspout outside.

To connect the wire to the downspout, I first sanded the downspout and connected the wire using three sheet metal screws. I used multiple screws to help ensure a low resistance connection. After making the connections to the downspout, I sealed them up using an adhesive/sealant called Goop. Goop is available at most hardware stores.

With the downspout behaving essentially like an end-fed wire, it really helps to work this type of antenna against a good ground. Fortunately, my basement operating position is only a few feet away from where the water supply pipe enters the house. I used a piece of 1/2-inch copper pipe as a ground bus between my operating position and the incoming water pipe. A tinned copper braid strap and a couple of ordinary automotive hose clamps were used to connect the bus to the water pipe. A short braid strap connects the ground stud on the unun to the copper ground bus.

For good measure, I attached counterpoise wires to the ground stud of the unun; one each for 40, 30, 20, and 15 meters. The counterpoise wires are made from garden variety stranded hookup wire cut to a quarter-wavelength. I just run these wires around the shack, hiding them under the rug. Operation on the 80 meter band has been successful using just the ground bus.

How well does it work? During the first few months of operation, I worked 49 states; all with 5 watts or less. I’ve also worked a bunch of DX stations (though I’m more of a casual rag chewer than a DX-chaser). The length of the “antenna” is somewhat short for 80 meters, but performance on that band has been a big surprise. Signal reports on 30 and 40 meters, my primary bands, have been consistently good. In fact, the downspout has been my main antenna at home for more than 20 years.

While this arrangement has served me well, it is not without an issue or two. I find that it helps to clean up and re-do the connections at the downspout periodically. Typically, I do this maintenance every other year or so. Also, I have noticed that my local noise levels on 80 and 40 meters have steadily increased over the years. I attribute this to the proliferation of electronic gadgets both in my house as well as my neighbors’ houses. Those bands are still usable, though.

Some words of caution are in order, however, if you plan to use your rainspout as an antenna:

Make sure your gutter and downspout are isolated from ground.
Make sure there is solid electrical continuity between the various sections of your downspout and gutter. Mine are fastened with pop rivets (not the greatest for RF work, but they appear to be doing the job.)
Watch your power. I wouldn’t recommend running a kilowatt into your rainspout. Ham radio is fun, but not worth burning down your house.
Make sure people and pets won’t come in contact with the “antenna” while you’re transmitting. This isn’t too much of a problem at QRP power levels, but be careful.

So, if you find your HF antenna options are limited by either space or legal restrictions, take a look at the outside of your house. There just might be a free multi-band antenna hanging out there!

72, Craig WB3GCK

Late to the (KX3) Party

I’ve toyed with the idea of picking up an Elecraft KX3 for the past year or so. I came close to buying one a few times but always talked myself out of it. I know there are many satisfied KX3 owners out there and I’ve used the KX3 several times myself so I was familiar with its excellent capabilities. It was just that my current stable of rigs was working fine and I felt no urgent need to replace them.

That all changed last week. I decided that a rig that has everything built-in (ATU, keyer with memories, etc.) was more suited to the kind of portable operating I typically do. Since ham radio has been my main pastime since I retired, I figured I was deserving of a new toy. So, I fired off an order to Elecraft and two days later it arrived.

KX3

While I was waiting for the radio to arrive, I spent some time reading through the user’s manual. I wanted to gain some familiarity with the KX3’s mind-boggling array of features before I got my hands on it. The basic operations were fairly intuitive but it will be a while until I feel like I have mastered this thing.

Barely out of the box, I had the KX3 set up and connected to my infamous rain gutter antenna. The KX3 tuned it up nicely on all bands. The filtering and noise reduction really did a nice job with my local noise problems on 40 and 80 meters. While I was tuning around on 20 meters, I had an SKCC QSO with Andy, EA5IIK. A DX QSO while running 5 watts into my rain gutter? For the rig’s first QSO, that’s some good mojo!

It took me a while to join the ranks of KX3 users but I’m finally here and looking forward to many QRP outings with this great rig.

UPDATE (5/19/2016):

It figures… A week after I get my KX3, Elecraft announces the smaller and less-expensive KX2. I guess I’ll need to start saving my pennies again!

72, Craig WB3GCK

New AlexLoop Tripod

As mentioned in a earlier post, I have been using the Vivitar VPT-1250 tripod with my AlexLoop, as suggested by the vendor, Alex PY1AHD. The Vivitar tripod has a few advantages. It’s very light, fits in the AlexLoop carrying case and it’s inexpensive. On the downside, it’s not particularly rugged. It’s a great solution for casual operating but I wanted something a bit more robust for operating in the field.

UltraMaxx Model# UM-TR60BK tripod. The camera mount and carrying handle have been removed.

After doing some searching, I came across the UltraMaxx UM-TR60BK. It’s 60-inch tripod that is much sturdier than the Vivitar tripod. In particular, the very bottom sections of the legs are thicker than those of the Vivitar tripod. The bottom sections of the UltraMaxx are about 19/32″ (13.7mm) compared to 5/16″ (7.85mm) for the Vivitar. It also wasn’t very expensive. I found a source on eBay for less than $20 shipped.

Comparing the diameter of the bottom leg sections of the UltraMaxx Model# UM-TR60BK tripod (top) and the Vivitar VPT-1250 (bottom).

One nice feature of the UltraMaxx is the accessory hook at the bottom of the center post. This can be used to suspend some weight to help stabilize the tripod in windy conditions. I envision using a bungee cord between the accessory hook and my backpack on the ground beneath the tripod.

UltraMaxx UM-TR60BK accessory hook on the bottom of the center post.

Adapting the UltraMaxx tripod for use with the AlexLoop was a snap. I easily removed the pan head/camera mount, leaving just the bare center post. The center post is just slightly smaller than the opening of the AlexLoop tubing. So, I took a velcro cable tie, doubled it over and placed it on the center post as I placed the AlexLoop over the post. This gave a nice, snug fit. I also removed the handle attached to the underside of the tripod; I don’t envision a scenario where I would use it.

This is how I arrange the Velcro strap before placing the AlexLoop on the tripod. This gives a nice, snug fit.

The sturdiness of the UltraMaxx tripod does come at a price. With the head removed, it only collapses down to 19 inches (48cm) compared to 14.5 inches (37cm) for the Vivitar. The UltraMaxx doesn’t fit inside the AlexLoop bag but it does attach neatly to the outside of my backpack. Also, the UltraMaxx weighs in at 1.3 lbs (584g) compared to 12 ounces (341g) for the Vivitar. For my purposes, this isn’t a huge trade-off.

I don’t plan to retire the Vivitar tripod anytime soon. It will keep its permanent spot inside the AlexLoop bag. It’s still a good solution for quick excursions to the local park. But when I’m out in more rugged conditions, I think the new UltraMaxx tripod will suit my needs a little better.

Now, all I need is some spare time to do some field testing the with the new tripod.

72, Craig WB3GCK

More Jackite Pole Hacks

Here are a few more things I have learned, based on my experience using Jackite telescopic poles. Although some of this might be fairly obvious stuff, hopefully, this will be helpful to some.

Dealing with Stuck Sections

About four months ago, I had the top two sections of my 31-foot pole become hopelessly stuck. After trying several things, I stumbled across a solution (at least for me).

My wife came home from the store one day with one of those rubber pads that are intended to help you grip and remove the lids from stubborn jars. A light went off in my head. I bought a couple of them at the local dollar store and by using them to help me get a grip on each of the two stuck sections, I was able to twist them enough to get them unstuck. A few months later, I again had two sections that became stuck. I went right for the grip pads and was able to instantly get them unstuck. I now keep a pair of these pads in my backpack for when I run into this problem again in the field. As a bonus, these pads work great under your paddles or straight keys to keep them from sliding around on the table.

This is one of the jar lid grippers my XYL found at our local dollar store.

Just a piece of advice. Don’t try to use pliers to get fiberglass mast sections unstuck. You’ll create a bigger problem for yourself. Don’t ask me how I know this. Just trust me on this one.

When wrapped around the two stuck sections of a pole as shown, these jar lid grippers help you twist the sections to get them apart.

Maintenance

This is sort of related to the stuck section problem. I use my Jackite poles quite a bit and they can sometimes take a beating when camping or at the beach in a salty environment. Dirt and debris might be contributing factors in getting sections stuck together. Just a theory on my part. I found that regular cleaning of the pole sections seems to minimize sticking problems.

Every other month or so (if I’m being diligent), I completely disassemble the poles. Then, I spray a little WD-40 on a clean rag and wipe down each piece of tubing. I wipe off any excess WD-40 with another clean rag and re-assemble the pole. It seems to work for me. After spending a week at the beach, this procedure is mandatory for me.

Bottom Cap Shock Absorber

When collapsing a 28-foot or 31-foot pole, the lower sections can sometimes come down so hard that they knock the bottom cap loose. To counter this, you can cut a thin piece of sponge and place it inside the bottom cap. I actually used two layers of that dollar store jar lid gripper material in mine. Just make sure whatever you use doesn’t interfere with the threads in the cap. This should help absorb some of the impact if you collapse the pole too quickly or if it comes down by itself in a strong wind.

This is two layers of material cut from the dollar store lid gripping pads placed inside the bottom cap of a Jackite 31-foot pole. The intent is to absorb some of the impact when collapsing the pole.

I hope some of this is useful to someone out there.

72, Craig WB3GCK

American Morse MS2 Straight Key

For many years after I first learned the code in the Navy, I was a die-hard straight key user. Unfortunately, back in the 90s, I started to experience some wrist pain and switched to using iambic paddles. Recently, after working one of the Straight Key Century Club (SKCC) K3Y special event stations, I was inspired to sign up with SKCC and dust off my straight keys. Hopefully, I will be able to get my old straight key fist back in short order.

Since I do most of my operating while portable, I wanted a straight key that was easy to pack and use while sitting on the ground along some trail somewhere. I was looking for something small that I could add some magnets to for use with my little clipboard.

After doing some research, I decided on the American Morse MS2 miniature straight key. I built a set of Doug Hauff’s (W6AME) NorCal paddles from a kit many years ago and they are still in regular use. Doug’s machine shop produces some precision stuff.

The kit arrived a few days after I placed my order. Following the manual’s precautions, I emptied the parts into a baking pan. Some of the parts are pretty small and would disappear forever if dropped on the carpet. Even with my aging eyes, it only took about 45 minutes to assemble the kit. (A younger person with better eyes and steadier hands could have done it faster, I’m sure.) You need to supply your own cable and connector, so I dug an old audio patch cable out of my junk box and cut it in half.

American Morse MS2 straight key after initial assembly

The key is 2 inches long by 1 inch wide and is made from machine aluminum. The contact gap and spring tension are fully adjustable. The key (with my cable attached) only weighs about 2.7 ounces (76 grams).

The finished MS2 straight key with cable attached. The cable is one half of an 1/8-inch diameter audio patch I had in the junk box.

After adjusting the contact spacing and the spring tension, I was surprised at how great this little key feels. The knob is a little different from most keys, but I was able to easily adapt to it. As expected, the overall quality of the key is outstanding.

My next project will be to attach some sort of base to it with magnets spaced to line up with the washers on the clipboard I use while portable. More on that in another post. I’m looking forward to making some SKCC contacts from out in the field.

72, Craig WB3GCK

Jackite Pole Repairs

As you can tell from other posts, I’m a big fan of Jackite fiberglass poles. My 31-foot pole sees heavy use as the main component of my Pop-up Vertical antenna. I also use it a variety of other portable situations, including my Bike Rack Vertical antenna.

Recently, I was in a wooded area and had the pole strapped to a signpost. While packing up to leave, the tip section got stuck. It refused to slide back into the next larger section. I noticed that the split ring I have attached to the top eyelet (see my Jackite Hacks post) had some damage. I’m guessing it got hung up in a tree branch when I was collapsing the pole. My downward pulling most likely caused the top two sections to become jammed.

Damaged split ring. (Click for full-size image.) — Damaged split ring. A possible clue as to how two sections of my Jackite pole became hopelessly jammed.

I have had these two sections become stuck once or twice before. I guess I’m sometimes a bit too aggressive when I extend the sections. Usually, a little WD-40 does the trick. Not this time.

I worked on it when I got home and wound up cracking the tip section. The two sections were still stuck together. After few minutes on the Jackite website, a new tip section and the next larger section were on order. I received a shipping notice the next day. The cost was reasonable. It was definitely less expensive than replacing the entire pole. A couple of days later, the parts arrived and the pole is ready to head out into the field again.

Thanks to the good folks at Jackite, I’m back in business. I’ll try to be more careful next time.

72, Craig WB3GCK

Disclaimer: I have no interests, financial or otherwise, in Jackite. I’m just a happy customer.

Jackite Pole Hacks

I’m a big fan of the Jackite fiberglass poles for portable antenna supports. I have two of them have have seen a lot of use over the years. Here are a couple of quick and simple hacks that improve (in my opinion) on an already great product.

Keeping the Cap From Falling Off

While the overall quality of Jackite’s products is excellent, there is one thing that I find annoying — the caps have a tendency to fall off when transporting the pole. To overcome this, I attached a velcro strap to the cap (Figure 1). The Velcro is something I had on hand in my junkbox. It’s about 8 inches long by 1 inch wide. I used a #4 machine screw with some flat washers, a lock washer and a nut (Figure 2). I used an awl and a small phillips screw driver to make the hole in the cap. I then attached two Velcro strips (the fuzzy part) on either side of the pole (Figure 3). When transporting the pole, just secure the Velcro straps (Figure 4) and you’re good-to-go.

Easy Extension

This quick mod might seem kinda pointless to some users. In fact, I hesitated about writing it up. Anyway, you be the judge:

In cases when I need to bungee or strap the pole to a fixed support, I would first need to extend the top-most section first. This is because the top section sits down inside the other sections when collapsed. What I did was attach a key ring (aka split ring) to the eyelet on the top section (Figure 5). The ring I used is approximately 7/8-inch in diameter. So, I can strap the collapsed pole to a support, remove the cap, reach in and use the ring to pull the top section out (Figure 6).

Again, you might not see the value in this one, but I find it helpful.

73, Craig WB3GCK