Most hams go through cycles of days or weeks or months where they operate more intensely or take a more relaxed approach. Those “lulls” might look like doing more listening, or working on projects, or making cables, or any of the maintenance things that need to get done. In my current situation I am balancing work, family, friends, and other interests against being on the air. A lazy Sunday walking the beach with a surf rod hoping to annoy some fish is not a time poorly spent. Neither is spending quality time with my wife. We have both been working from home for over 16 months and I think it has made it more important that we do fun things together now. Being stuck in the house together all day is not a substitute for real time spent together. Since I set up an antenna each time I want to operate there is a hurdle to getting on the air. That time is often during peak family time, and family often wins. Even then I am still practicing morse code, reading up on antenna designs, planning my next portable operation, and fine-tuning my VHF Rover setup.
In a way it is not unlike being a surfer in a lineup. You can never catch every wave. Some of the best time you spend might be sitting on your board enjoying the setting, watching the fish, or cheering on your fellow surfers. Here in Rhode Island we are in the heart of the summer beach season. It brings with it many opportunities for recreation, gatherings with friends, and even some solitude if you know what beach to be at and when. It’s hard to choose sitting at a desk (again) over watching the daylight fade while up to my neck in the Atlantic.
Every person has their own circumstances, and I can’t deny being a little jealous of hams who are active every day with permanent installations. I look forward to having that chance as my life balance changes. So, I wish I had a technical topic or an operating tip, but this post is about finding balance and making the most of time on the air when we get it.
OK, I lied! Here is a cool tool for JS8Call, written in Python by Groups.io user basho1600. It scrapes calls, grids, and QSO information from the JS8Call receive window and maps out the station grids with lines connecting stations in QSO. It’s a great example of how you don’t need to be developing executables to make something useful. Being open-source it can also be a starting point for another developer. This is the kind of feature that JS8 needs, and a user stepped in to get the ball rolling. BRAVO
When I was a kid my grandfather gave me a Hallicrafters S38-C, starting me down the road to radio madness. I had already been listening to AM Broadcast DX, though all I knew was I could hear the Red Sox games from other cities, like Chicago and Kansas City, late at night with my AM transistor radio under my pillow. Shortwave just blew my mind. I started to learn the bands, and some of the fixtures on those bands.
Shortwave in 2021 isn’t what it used to be. Most people comment on the decline in stations on the bands. That’s true, but I believe what they really mean is “big English-language international broadcasters” are fewer and weaker. Stations like BBC and Deutsche Welle no longer aim powerful signals to North America. We now hear a greater proportion of religious broadcasters, Latin American and Asian broadcasters, if we bother to listen at all.
Over the past year I found out about a program called Shortwave Radiogram. They broadcast a 30-minute MFSK program of text and images every week. Their programming runs on WRMI Radio Miami International and WINB in Pennsylvania. Check out their website for times and frequencies. It’s definitely worth your time.
The hardware required to participate is extremely simple. You can, and I have, decoded it via the microphone on the computer. No wiring or fancy interfaces needed. You can also just run a 3.5mm stereo patch from your radio to the computer soundcard. You aren’t transmitting so isolation shouldn’t be necessary. I use the same laptop rig I use for all my digital ham radio work because I usually have it set up and ready to go. I set FLDigi to RXID and it will switch modes based on the RXID header sent before each text block or image. The copy today was flawless. My rig was a Yaesu FT-991A with a DX Commander Expedition Vertical. I have done this with a Sony IC-7600G and the built in whip. You don’t need a monster SWL setup, just a receiver and a computer.
First, they play a spectrogram header which I never get around to screengrabbing. Then they have a few text articles of interest. Today I copied (most of) the broadcast. I made a mistake on my soundcard setting so I missed the beginning but captured this:
“…32 m (105ft) long, featuring the company’s own proprietary “Inductrack” mag-lev technology and sensor-embedded “Vibranium” carbon fiber skin.
It’s laid out some 320-odd m (1,050 ft) of fully functional test track in France, vacuumed down to hundred-pascal pressure levels lower than what you’d get at altitudes over 38,000 m (125,000 ft). It’s long enough to do some initial tests, but obviously not to approach the 1,220+ km/h (760 mph) top speed the passenger system is projected to hit when it’s got some room. The company has signed some exciting-looking deals in India, China, the USA and the United Arab Emirates over the last six or so years, but no full-scale implementation seems to be under construction yet.
Fair enough; the World Bank estimated in 2014 that even a regular high-speed train track costs somewhere between US$17 million (in China) and $56 million (in California) per kilometer of track. And that’s without putting the whole thing in a huge, airtight tube with vacuum pumps and some of the largest, strongest mechanical pressure valves ever built dotted along its length. The up-front capital cost of a cross-continental supersonic hyperloop system would be epic – but once up and running, HyperloopTT says it could deliver “airplane speeds at freight costs.”
The HyperPort development proposes to plug container shipping logistics into the mix, with freight capsules designed to open at the top and accept either two standard 6-meter (20-ft) shipping containers or one double-length 12 to 13.7-m (40 to 45-ft) unit, dropped in and picked up by the same sorts of gantry cranes that already load and unload container ships. Freight speeds would be limited to around 965 km/h (600 mph), so either the passenger pods would have to slow down to this speed as well, or separate tracks would be needed.
It’s all very pretty and futuristic-looking, and HyperloopTT says it’s designed everything to meet current industry standards. The HyperPort is now being submitted for certification design review, and the company says the next step will be a VR demonstration, to be presented at the ITS World Congress in Hamburg this October.
It’s a long and winding road from concept to reality, obviously. And while a solution like this would indeed be much faster and greener than the battalions of trucks that get the job done today, battery and fuel cell trucks are on the way, ready to haul containers to anywhere roads can take them, with zero local emissions.
The crazy speeds promised by the HyperPort will come at a hefty cost, but they could cut down a lot of road miles and get things moving even faster in a world whose patience grows ever shorter. I wonder if we’ll see this kind of thing get done – vacuum tube transport seemed just years away back in the 1800s too. Between Virgin Hyperloop, HyperloopTT, TransPod and other companies, it seems investors feel this kind of thing is ready for prime time.”
After this they broadcast a selection of images. Here are the images of the day, with the captions broadcast with them:
Check out the SWRadiogram website and give it a try. The ability to set this up for unattended decoding/recording makes it very convenient. Can you think of any other services (ARRL Maybe?) that could benefit, or act to the benefit of listeners with digital capabilities in this way?
When I was running mobile HF in the 1990’s and early 2000’s I accumulated a bunch of 3/8-24 mount antennas. There were hamsticks, Hustler coil-loaded whips, an Outbacker Perth, plain whips… Outbacker sold a metal tripod that was marketed as a ground plane and antenna mount in one. I didn’t spring for that. I just bolted a 3/8″ coupler to a cut-down surveyor’s tripod, made a quick and dirty radial plate, and gave it a go. It worked. It wasn’t great but it gave me a different way to deploy those mobile-mount setups. At that time these “stationary mobile” solutions were a novelty setup among the hams and publications I interacted with. A simple dipole was always going to crush that mobile antenna, and did.
FFW to the vaguely 2020-ish period and somehow ultra-portable field antennas, mainly for QRP use, are flying off the shelves. In the depths of a solar minimum, no less. The effectiveness of these systems is a tribute to the radio arts in general. Getting a signal onto the air is still job #1. The vagaries of propagation and the system on the other end of the QSO take care of the rest.
Three of the most popular categories today are end-fed wires, linked dipole/monopole, and coil-loaded verticals. Some designs hybridize these approaches. I’m leaving the brilliant DX Commander line out of this because I think they are portable with an * in that it isn’t a trivial thing to set up. I own one and will be giving it the treatment it deserves soon.
I currently maintain a small armada of portable antennas and they all have their strengths and weaknesses. Today I’m going to examine two designs that have some similarities, some differences, and I feel they fill a similar niche:
The Chameleon MPAS Lite is an end-fed design based on a CHA Hybrid-Micro (roughly 5:1 un-un), a very nice 17′ stainless steel telescoping whip, and a burly stainless steel ground spike to mount them on. It also comes with 50′ of medium duty feedline RG-58-looking coax with a ferrite-bead common mode choke installed, and 60′ of tacti-cool PTFE insulated he-man wire on a heavy duty winder. A supplied stainless steel D-ring on a 3/8 stud allows the CHA Micro to feed a wire (The supplied wire or your own) for NVIS and other “mo’ radiator mo’ betta” setups. Not coincidentally it has the look and feel of the Jeep of portable antennas. I would not want to be on the receiving end of that ground spike wielded in anger.
The Wolf River Coils SB1000 TIA, Mega Pod is a self-supporting HF vertical antenna system. The SB1000 is a sliding-contact adjustable coil. This design is immediately familiar to any mobile HF op. In fact many users deploy the Silver Bullet series coils in HF mobile setups and their reviews indicate satisfied customers. Think of a screwdriver coil without the screwdriver. It feeds a stainless 102″ (8.5 foot) whip, and the coil is designed to load that whip from 80-12m. The kit comes with three 35′ wire radials, and the Mega-Pod. The pod is a machined aluminum hub with three 3/8″ tapped holes at 120 degree intervals, and a standard SO-239 to 3/8″ stud mount adapter mounted through the center. Three aluminum rods with threaded ends form the legs, which also act as radial attachment points thanks to the provided lock nuts. It’s a good, reliable design and the use of aluminum in the Mega-Pod helps keep the overall weight down.
Portability and Ease of Operation
Both antenna systems are light, portable, set up and break down easily. The Chameleon has a smaller footprint due to only using one (or zero) radials. The WRC needs a larger area to spread out the radials, which are key to both tuning and performance. The CHA Spike is quicker to set up and less fiddly than the Mega-Pod. The Mega-Pod can be a little springy and while not unstable is not rock solid stable. I don’t think it needs to be overbuilt. The threaded rods and lock nuts let you set the nut at a point before the rod bottoms out, and then tighten the rod against the radial lug. Don’t hesitate to put all three radials on one leg. It will work the same and it’s easier to set up that way. If you really needed it to be easier you could make lugs with extensions terminated in your choice of quick connector and then terminate your radials to match. I think that is overkill. The spirit of the WRC TIA is to have a working setup without a lot of fuss. The TIA Mega-Pod is more of a casual, less “tacti-cool” piece of gear, but it still effective.
With either setup you can be on the air in about 5-10 minutes. The CHA will set up faster, but neither is a chore. It hasn’t escaped my imagination that the CHA Spike is a really nice way to mount the WRC. In fact you could also imagine running the 17′ CHA Whip on the SB1000 and having a 80/40 setup with a better radiator.
The user can get the WRC tuning very close by listening for peak noise on the band of interest. Once the user gets close it can be a bit of a chess match to get it zeroed in. The TIA is easiest to tune if you have an antenna analyzer or other SWR sweep device. I first used this antenna with a Xiegu G90 and the internal SWR sweep/analyzer was a big help. My old MFJ-259 makes it easier still. The key is being able to sweep around the band to determine if your current tuning is low or high. Once you are close it only takes small tweaks to move the resonant point. Without much fuss I was able to tune it on 80m through 12m. You can get it on 10m by shortening the whip, or just using the whip alone.
The tuning reference points in the WRC instructions will get you in the ballpark, but all kinds of external factors can change the amount of loading you will need. Tuning the stock setup with the three radials over average ground is what the instructions are based on. YMMV. As discussed in a previous blog post I consider a base-loaded whip to be in the “tuned circuit” family. The whip isn’t resonant, but the coil is making a resonant circuit for the frequency of interest. The apparent Q of the design is “moderate”. Not razor sharp, not super broad, but it can be touchy once you get the coil contact close to your tuning point. You probably won’t need a common-mode choke, but I always bring one because… RFI Happens.
The MPAS Lite is a whole different concept. It is not designed to show a low SWR on any band. The design assumes you have a matching device between your rig and the Hybrid-Micro. You might get lucky and see a sub-2:1 one one band and it might be fine. I typically see SWR values between 1.5:1 and 5:1 without a tuner. My 991A has a built in tuner and matches it with no complaints. I use a LDG Z817 with my IC705 and that matches it easily as well. With a manual tuner you are back to peaking band noise then fine tuning. My MFJ 901 will tune a watermelon, so it’s no news that it was great with the MPAS.
The three 35′ radials supplied with the TIA are both the bare minimum, and also seem to be enough. I tried adding three bundles of three 20′ radials in addition to the supplied ones and it didn’t seem to help much. If I was trying to improve on the system I would try three 20m radials marked off at the 1/4 wave points for each band of interest. Just unroll the radials to the band marker. Of course this means you need over 60′ in each direction on 80m. Tuned radials have the potential to improve the performance of this system. It could be an interesting project. It also might not matter too much.
As for using a counterpoise or radials on the MPAS… one, zero, five, nine? In my experience the performance of these systems is unpredictable in the literal sense. If it gets you on the air it is working as advertised. Counterpoises in an untuned system are a funny business. When the radiator is not a resonant length I think you can do more harm than good trying to run tuned radials. I typically attach the CHA Radial and lay out about 25-35 feet of it in a convenient direction. If you are having tuning issues just change the counterpoise length/config or remove it entirely. Like a 9:1 end-fed the function of the counterpoise is debatable. It also might not have the same function in every deployment.
In a related topic, the MPAS isn’t limited to using the 17′ whip. You can attach whatever radiator you want and it will probably work. I believe the best to approach to sizing a wire radiator is to keep the suggested lengths for 9:1 un-un operation in mind. The transformer ratio might be different, but you still don’t want resonant lengths if band flexibility is on the menu.
Both matching units have loss issues that result in heat buildup. The WRC SB1000 is rated at 100W SSB, 50W CW, and 20W Digital. Similarly the CHA Hybrid-Micro is rated at 100W SSB and 50W continuous. I think a conservative approach to power output is wise here. You can smoke either device if you get too aggressive with the power. On the TIA the coil is trying to load a 102″ CB whip on 80m or 40m. This is a lot to ask and there are plenty of examples available on forums like eHam attesting to either deformation of the coil former, or outright failure when pushing the power ratings. On the Hybrid-Micro I would just assume the match at the feedpoint is bad, and that will make a lossy system worse, and that makes more heat. Heat Bad. I won’t run more than 35w in digital mode on either, and no more than 50w in SSB/CW.
I will be running a side-by-side test of the two systems soon. For now I will just give my impressions of them based on using them in the field using the same radios under similar conditions. I’ll get the bad news out of the way first: Neither is a fantastic antenna system when compared to almost anything else. Short radiators and lossy base loading are not a recipe for great antenna performance. However these antennas are not marketed as high-performance DX machines. Their calling card is portability and ease of deployment. In that respect they are both very good systems. Perceptions of on-the-air performance will have a lot to do with expectations, operating style, location, and whether making a specific contact at a specific time is essential. I have used both on POTA and POTA-style outings and they both hear much better than they get out. That’s normal. I felt like I was taking advantage of my “always loud somewhere” approach on every contact. I would be unable to work a solid 4-lander from RI (normally a given) but I might be getting 59+ reports from Kansas or Idaho. You will make contacts on either. You will make a mix of stateside and DX contacts. And no, these are not just pricey dummy loads.
The TIA got my initial performance nod based on my preference for tuned circuits over broadband transformers. But the TIA uses a whip that is half the length of the MPAS, giving up some if not all of that advantage. Also, if you run those TIA radials out to full length (recommended) you will need something like a 60-square-foot area to lay it all out in. The design is a little quirky and the user needs to be more involved with those quirks. It’s built out of hardware store parts and stainless wire. That isn’t a knock. Any ham will look at it and know that WRC puts a lot of care into their product and they are getting good value.
If you are intending to do a lot of band-hopping you will be much happier with the MPAS. Hitting “TUNE” and being ready on a new band is certainly seductive. It comes at the cost of additional system losses, but if you are making the contacts you want to make it doesn’t matter too much.
Aside from being a snap to set up in the field these antennas are providing regular HF capability to hams who may have given up on running a “real” HF antenna on their property. That’s great and the easy setup, small footprint, and low visibility are big selling factors. A concern I have expressed here and in other places is that there seems to be some confirmation bias among hams who haven’t worked with better antennas. I’ve seen excited reports of working monster Slovenian contest stations with one of these antennas and 10W, and I hate to tell you that is not a measure of *your* antenna’s performance. I’d also point out the fine work of Thomas Witherspoon, K4SWL, on his YouTube channel. He has many great real-time videos of an array of QRP rigs with different portable antenna solutions including the MPAS line. Note that he is almost exclusively calling CQ, hence pre-selecting stations that can hear him. If he was chasing stations with the MPAS he would need to take a very different approach. I don’t mention this as a negative on these antennas or the users. I mention it as a point that might be of help interpreting on-line reviews including this one.
Bugs and Observations
None of these issues are “deal-breaker” serious, but each antenna has some quirks and design issues:
I found that I needed to keep wrenches in my kit for the WRC because the 3/8″ hardware gets stuck together. It was a little annoying and I think a couple of inexpensive adjustable wrenches are a good accessory to keep with the WRC kit. Disassembly might also result in the SO-239 to 3/8 adapter coming loose on the Mega-Pod hub. I have a spare Hustler quick release that I am thinking of using to knock these issues down.
As I mentioned, the WRC Mega-Pod can be a little springy. Some care is required when deploying it, especially making sure you have slack in case of a trip or snag. The WRC whip isn’t going to take too many flops before it needs serious attention.
The MPAS Lite has fewer parts and doesn’t have much to go wrong. Still, I feel like the knob used to secure the counterpoise feels tacked on. It’s has red plastic knob and a small threaded rod which will only grab the eyelet on the CHA Radial by a corner. It doesn’t seem like it will make solid, reliable, electrical contact. It stands out mostly because everything else is so burly. Note: Unlike the SB1000 coil, the CHA Hybrid-Micro is not rated for mobile use.
As you can tell I want to review these systems for what they are. They both work as designed to allow quick setup in tight spaces and allow operation across the HF bands. They both use standard 3/8-24 hardware allowing the user to mix, match, modify, and experiment with the provided building blocks. I haven’t touched on cost but the MPAS costs more than twice the tag on the WRC. Value is so subjective that I will just say that both feel like they are priced right. Also, I don’t feel like one is a big performance winner over the other.
If I was looking for an affordable portable setup to use around the campsite, for instance, The WRC TIA is a great option. I’ve covered the setup and tuning procedures. The result is being able to work on many HF bands with no additional tuner needed.
If I had to deploy something as fast as possible, with the least hassle, the winner is the MPAS by a large margin. You will draw very little attention, take up very little space, and get on the air. Even though a transmatch is required it doesn’t seem to be much of a hurdle. I used several matching units, including the MFJ-901, and they all worked just fine. You can also load a long wire, end-fed inverted vee, vertical wire… so the system is more flexible than the WRC.
I hope this post has been helpful. I have enjoyed using these systems, and can see why they maintain their popularity. As long as your expectations aren’t for some miracle system that gets big antenna performance in a small package then you can expect to get a lot of enjoyment out of either.
The reason why I would bother with this topic is twofold: One: I think better antenna systems are actually better; and Two: Technical concepts are central to amateur radio and should be understood and employed as often as possible. I’m discussing these antenna concepts in simple terms in the interest of keeping it accessible. Hopefully it leads to some further investigation and a different way to think about antenna systems.
WHAT IS RESONANT?
In the Venn Diagram world it can be said: Not all 50 Ohm feedpoints are resonant, and not all resonant radiators present 50 Ohm feedpoints. I have seen much confusion between “resonance” and “impedance match” on internet forums/platforms/videos. This what drove me to churn out this post.
Resonance in an RF radiator actually does make a difference. I’m a fan of Hemholtz and resonance is a real thing. When I assess a antenna design I start at the radiating element or elements. If that element is not a known and desirable harmonic relation to the fundamental frequency of interest I consider it a non-resonant design. If there is a matching unit connected to a non-resonant radiator I consider it a tuned circuit. When the goal is efficient and predictable RF radiation you have resonant radiators, and then everything else.
Recently there has been an explosion in the use of end-fed wire antennas. I use a few of them and they are an easy way to get on the air, usually on multiple bands. I have made plenty of contacts on these antennas, but at no point was I under an illusion that I was using an efficient antenna system. The now ubiquitous End Fed Half Wave is a strange bird, It utilizes a half wave radiator with a feedpoint impedance of about 3000 ohms, and is operated without a traditional ground plane or counterpoise. The high impedance feedpoint is matched to somewhere near 50 ohms with a 49:1 or similar toroidal un-un transformer. That is not a recipe for efficiency. The power ratings on the matching transformers tell you all you need to know: These matching units get hot, and that heat is your RF not making it out into the world.
That’s not to say it’s a bad design. It solves a few of the issues that keep many hams from being able to get on HF. You can hang it from a single support, as opposed to needing two or three for a horizontal dipole. It’s also easy to erect on demand, which is great for hams who want to operate portable stations or if they have a compromised (small, HOA, etc…) QTH. I use a 12m Spiderpole and a PAR Trail Friendly when Inwant to get on the air quickly. Also, thanks to the magic of harmonic resonance, it is common to find a match on more than just the fundamental frequency.
Another common design is the random length end fed, usually known by the 9:1 un-un transformer used to feed the non-resonant radiator. The trick here is to find a radiator length that is not resonant on any band you want to work. The hope, and I do mean hope, is that the feedpoint impedance will be somewhere in the 200-800 ohm range, where it can be matched to 50 ohms using a second matching device. Again it has the advantages of ease of setup and multiband capability. The tradeoff is even steeper than the HWEF. This design is force-feeding a non-resonant radiator, has an even lossier (IMO) un-un, and requires a second matching device to get all the way to 50-ohms.
A problem both designs share is the difficulty in modeling a radiation pattern. Even with many analyses and many users over many years nobody seems to be able to say much beyond “omnidirectional”. That’s not too helpful. The main issue in modeling these systems is properly representing the ground/counterpoise. Most installations (mine included) require a common mode choke (CMC) near the radio end of the coax to keep RF from energizing the radio’s earth ground. How efficient does that sound? Do we have any idea what these antennas are actually doing wit the RF that makes it out into the world? Empirically I think we do. Scientifically, predictably, I don’t think we have a good handle on it.
So, how important is the efficiency of a transmitting antenna?
Hams with even some basic experience on HF know that you can make contacts on almost anything. Take a simple transmatch design like the MFJ-901, hook it to a rain gutter, and make a contact. Do we know anything about the radiation pattern, efficiency, or bandwidth? No. We are just interested in forcing something conductive to radiate RF, and hope for the best. The magic of radio waves takes care of the rest. If enough of your RF makes it out in the correct direction you will make a contact. Your signal might even be strong! But this is where it helps to be aware of confirmation bias. The science of radio communications involves being able to control where your signal is going, and control the system design to connect you with the intended destination. Having made some contacts is almost inevitable. Making the contacts you want to make when you want to make them is where the game gets interesting.
In the food-chain of antenna designs these lossy designs are somewhere in the “krill zone”. A good efficient design, properly installed is somewhere in the “cordata zone”, and a very efficient directional design mounted high and in the clear with directional control is “blue whale” territory. At some point the operator is limited by their Effective Radiated Power (ERP) and the weakening of the transmitted signal with the square of the distance from the antenna. Using 10-30% of your RF to warm a toroid is cutting in to your effective range. Every system has limitations, but when running 10, 30, 50 watts at the finals, I feel that making the most of it is important. Every improvement in efficiency and pattern control brings you up another link in the radio food chain.
Certainly the parallel popularity of end-fed wires and weak-signal digital modes, best represented by FT8, are not coincidental. FT8 allows working at lower signal to noise ratios which is like getting that lost RF back when compared to working SSB or RTTY. More efficient antennas are always an improvement, but an entry-level HF rig, a HWEF, and WSJT-X is a great path of entry to the HF bands. I’ve gone on about this earlier, but there is nothing in-stone about needing to start with CW or SSB. Hams can get on the air, interact with DX, and get some good contacts in the log. I see nothing wrong with that.
Compact, Broadband, Efficient: Pick Two
In the HWEF and 9:1 design cases the user is giving up efficiency for a more compact, more broad-banded (lower Q) device.
The HWEF, thanks to its resonant radiator, is somewhat more efficient, but the price is being paid for getting wide frequency coverage on a single radiator. Some designs find ways to better balance the equation by sacrificing some bandwidth and band flexibility to increase efficiency. One QRP design I use is the PAR 102040 Trail Friendly. This design uses three techniques to get a three-band end-fed vertical into a single 41′ wire radiator package. Trick 1: It uses a trap to isolate the 20m half wave element from the 40M extension. Trick 2: It uses the characteristic electrical lengthening effect of the trap to keep the 40m extension (and overall length) shorter than a simple 40m half wave radiator. Trick 3: using the second harmonic of 20m to realize some usable bandwidth on 10m. The transformer is pretty much handling the design goal of representing a 3000 ohm feedpoint as a 50 ohm load to the rig. No additional trans match is needed if you have trimmed the 40m extension properly and are ok with the tuning points. It isn’t brilliantly efficient, but it’s not horrible.
Chameleon MPAS Lite – Mini Review:
In early 2021 I picked up that Chameleon MPAS Lite and wanted to give it a run as a portable antenna system for POTA. This unit is extremely compact and is comprised of a ground spike, a un-un, a heavy duty stainless whip and 65’ of wire to use as a counterpoise. With the engineering triangle in mind I knew I was giving up a lot of efficiency for a very compact, very broadband system. And that’s what I got. It works well enough, especially if you are calling CQ and self-selecting stations who can hear you. I found that replying to anything but the loudest stations was a bad recipe for success. In a Chameleon forum I made the comment that these antennas aren’t good DX setups. I stand by that. It isn’t that you won’t work any DX, you would just work more DX more easily with a better DX design. For mid-range and NVIS work I think it is a solid solution. That assumes you are able to make the contacts you need to make. Also, watch the power rating because the un-un will get warm, and will fail under excessive power and duty cycle.
The MPAS system uses a 5:1 un-un design to feed anything from their very nice stainless whip, MIL Whip system, a longwire, or whatever conductive item you decide to use. The 5:1 takes a conservative approach to the non-resonant radiator problem, and a second transmatch (internal or external unit) is required unless you get lucky and dial in a 250 Ohm (or 10!) feedpoint impedance for the Un-Un. Chameleon publishes a perfect omnidirectional pattern for their antennas. That’s a good assumption for the operator since non-resonant systems are difficult to model accurately. Just assume your RF is going in all directions equally. Might as well! In practice I have made contacts and successfully activated a few parks using the MPAS Lite. Chameleon builds a beautiful and rugged product, and supports their users well. II feel like it is a good system and the user will get the best out of it by realizing it’s strengths and weaknesses.
One concern I have from following a few antenna forums, including a Chameleon product support forum, is the number of users claiming to have “resonant” solutions. An actual resonant radiator would provide a terrible match with a 5:1 un-un. What users are doing is finding a radiator length that presents a 1:5 feedpoint impedance to the CHA transformer so the radio sees 50 ohms(ish). That approach may be usable on that band with no additional matching, but is likely to be worse on other bands.
Another constant question on these forums regards radials and counterpoises. Strangely the solutions discussed are often none, one, or several short radials. All of these are poor solutions. However, when the central design concept is to never be resonant, not require radials, and use almost anything as a radiator, I don’t know what a good solution looks like. The Chameleon counterpoise kit is 65′ of very hunky insulated wire and can help you play with the counterpoise dimensions/layout and maybe help in finding a match. That said I feel like users are trying resonant counterpoise lengths and I think that does more harm than good. With a single counterpoise, stick to the game plan. Why make the two impedances different?
The Chameleon 50′ RG-58-ish feedline with a ferrite bead choke on one end is a decent way to control the stray RF. And it is necessary. Every time I have used it I had to control RF that wanted to energize the radio’s earth ground.
The best application I have seen for these matching units is Chameleon’s own Tactical Delta Loop which uses the CHA as the feedpoint in a system where 5:1 isn’t a bad design value. I will be cobbling a test setup soon out of various Chameleon and Wolf River parts.
If it sounds like I am down on end-fed designs, I’m not. They have a proven track record and get hams on the air. What I would like to get across is that I hope ops get some time on other designs. Building a nice 1/4 wave vertical over a good set of radials is very easy and cheap. Think of a it as a single-band DX Commander style build. I think it is worth the time and small expense to see how a resonant design works and maybe make a few on-air comparisons.
If you stuck with this post I owe you a pint. I don’t write these to be concise blurbs. I like to compose my thoughts on these topics and I figure sharing it is part of the experience. Let me know what you think! Reply on the blog, or look me up on QRZ and drop me an email.
Get on the air, and always have fun. 73, Pete N1QDQ
When I was first licensed in the early 1990’s I traveled a fairly standard ham radio pathway. I bought a Kenwood TH-78a (There were no ‘Fengs) and I already owned a few decent SWL rigs. I had access to all the test equipment I grew up with, and had my dad as a tutor on some electronics concepts. I needed that because I went from Tech to Extra in about 8 months. That also involved learning code. I passed the then-maximum 13wpm, but was able to pass a 20wpm for fun a few months later. The basics of VHF repeater operation and HF SSB/CW are still a large part of my ham radio experience. I also had interests like hiking, camping, road trips, and I liked to build antennas. It wasn’t long before I found out about VHF contesting, and the Rover classification. I worked with another ham, N1QVE, to assemble a rolling station and we did some good work in VHF contests in the 90’s.
I have been in and out of active ham radio operating for about a decade. It wasn’t until 2019 that I started thinking about improving my equipment and getting something better than my attic dipole for HF. I also had one eye on VHF all mode operation. I owned a Ten Tec Scout for HF mobile, and few of the Icom single-band VHF rigs like the IC-202/402/502 for VHF SSB/CW. Then I splurged and bought a “shack-in-a-box” Icom IC706, soon upgraded to the IC706-mkII, and that was my main radio for a few years. I’ve since owned a few of the Yaesu FT-857/817 family, and found them to be great radios. Looking around the catalogs in 2019 there were not many V/U All Mode options. I was running a Xiegu G90 (great rig) but it had no VHF+ capability. I decided on a Yaesu FT-919A and have been very happy with that radio.
2020 ARRL September VHF – Initial Low Drag Rover Concept:
In the summer of 2020, COVID-fever was at a max and any reason to get outside was a good reason. I used my free time to scout a few hilltop locations and figured I would give the ARRL September VHF Contest a go. The design restrictions were pretty simple:
Single Op setup, so everything had to be riggable by me, alone, quickly, in whatever conditions I dared operate in.
I ruled out operating on the road. I would only operate fixed. My days of running a recorder in the car and reviewing audio logs were well behind me.
No major gear purchases. I only do it for fun, so why shell out for an extra few DB here or there
Keep the rove manageable and fun. No slogging through vast stretches of highway in the dark of night for a possible grid activation.
I packed my 991A, my ELK LPDA, and a PVC mast on top of a PA speaker stand, and hit the road. I had a good time and actually racked up a respectable 2,325 points on SSB only, logging by hand, and only having a 5/8-wave 2m whip for 6m. This is how I learned to do it over 20 years ago, so why add more complexity for my first outing?
2021 ARRL June VHF – Lessons Learned
Over the nine months since the September contest I have put together a better portable setup for both POTA-style HF ops as well as VHF hill-topping and contesting. I built a wire Moxon for 6m and tried it out in the January VHF contest (a wind-driven washout), and liked it so much I purchased a PAR SM-50 Stressed Moxon and have been running it for a few months. I also upgraded my homebrew “tesla cell” LiFePO4 battery to a Bioenno 20A unit. As for my antenna rigging, some time in a hardware store with calipers netted me a 12-foot painter’s pole that is a slip fit to the ID of my speaker stand tubing. It also has an aluminum hex shaft which is perfect for the SM-50 mounting clamp.
I am still running RG-8X feedlines, and am not running any preamps, or power amps. This means I am making 50W max on 6m and 25W max on 144/432 with the 991A. It really is enough for the kind of operating I am doing. There is a huge spectrum between “stay home” and mega-rover. Even if the scoring system has no way to identify the details, I know my score came from single-handed barefoot operation with simple and affordable antennas.
I also made the switch to computer logging. While it *almost* violated my “no new gear on contest day” mantra, I picked up N3FJP’s VHF Contest logger and had enough time for a brief dry run before contest weekend. I knew I would have to work out the fine points under contest conditions, but I also brought a pad and pen JIC. I also ran WSJT-X to get me on FT8. I wish I had success with employing the multicast protocol because I missed having GridTracker, but maybe next time. TIP: Let N3FJP handle rig control. I lost mode tracking when I let WSJT-X control the rig.
VHF Digital Lessons/Issues:
I have been lucky enough to operate FT8 during some good 6M Es openings during May and June 2021. My experiences on HF FT8 translated very well. I was able to use the same techniques of moving my transmit frequency, strategic CQ calls, and so on. I expected things to work just as smoothly during the contest. Yes, there is one born every minute.
I had never operated WSJT-X in contest mode before and hadn’t really thought that through prior to the start of the contest. As I set up and started making a few pre-contest trial contacts it hit me that something was different. For one, the QSY on left pane double-click acts differently. As well I was having bad luck when replying to CQs while transmitting in a “clear spot”. I often had to reply on the calling station’s TX frequency. So while the potential for digging out more QSOs by working weaker stations was there, the reality was not so simple. I could have worked SSB stations much quicker, and “run the bands” much easier… if so many stations weren’t ditching SSB for FT8!
I put in a fair amount of time, at least 25%, working non-digital modes. There were times when I was making good contacts, and others where the CW/SSB was dead and FT8 was the only thing where a contact was possible. I was able to work W1AW and W1AN on 6M CW from Mowhawk Mtn. That was pretty cool. As much as I enjoy digital modes I do think the CW/SSB action is more enjoyable.
I decided to activate FN41,42,31,32 this year. The 1800Z start time for Saturday of the contest is a real style-cramper. I get it, but really? For a rover it leaves about seven total hours of daylight on Day 1. With many parks closing at sunset the decision to move locations cuts into a lot of operating time. My memories of driving through the night and only making a few new contacts, while hearing the same big-gun stations made the decision simple: Start on time, wrap it up at dark, get home, get some sleep, and put in a good shift in FN41 on Sunday.
Now that I live in coastal Rhode Island it makes the route-logistics a little more complicated. I started the contest in FN42 at a hilltop in Charlton, MA. That spot is great but they are all only as good as conditions (foreshadowing) allow. If I had just stayed there until dark I would have had a better overall contact/points total, but I was up for a drive and wanted to try a new spot for FN32.
After many different ops operating from hilltops in the NW Connecticut and Western MA area (FN31,32) it is hard to break that habit. They are good locations, but not perfect. That spot was the parking lot at Haystack Mountain in Norfolk, CT. It’s got a lot of trees blocking the RF/View, and the entire northern half of the azimuth is blocked by a mountain, but it isn’t terrible. Not great either. You get about 100 degrees of actual azimuth to play with from maybe 120-240 degrees.. Next was Mowhawk Mountain in Cornwall, CT. Mowhawk is a great location, but there is a lot of RF equipment up there and noise/intermod levels can by nasty. Bring your bandpass filters! Neither location “popped” but I did activate the grids and get a few new worked grids in the log. All in all not worth the drive (points-wise), but on this beautiful June day the drive was spectacular.
I had a nice time operating on Sunday from FN41. A local high-ish spot at a local farm field gave me plenty of elbow room and a safe off the road location to operate from. The RF conditions were not super. Normally I’d be ok with hearing some distant grids but not being able to work them. I wasn’t even hearing that! It was a grind. I did manage to get some good runs on 6m and 2m, add a few worked-grids, and even snag some DX with a VP8 and an EA7. What we had here in the northeastern US was a nice opening to Europe! Even then I wasn’t hearing too many Europeans. It was just a soft day on the bands. After about 5 hours I worked a nice run of locals on 2M FT8 and called it a day.
It wasn’t a terrible contest. For the type of operation I describe here it was a success. It looks like I tallied just north of 3,500pts, activated four grids, and put on about 300mi. Those are Southern New England Miles. It’s like dog years compared to other parts of the US. I think it’s fair to say conditions for this contest didn’t favor my low power setup. I was counting on a strong opening to the mid-west or southeast and it never materialized. Fun was had. I’m looking forward to the next one.
Rovering is a great way to wring out your mobile/portable setups. I feel like my POTA setup got better, and I have a few ideas for improvements.
Something was very odd with beam headings. I felt like I was way off heading on a few contacts where I set the beam heading by ear.
Also, setting the beam heading on FT8 while armstrong-ing the mast with one hand and reading the screen and running a mouse is not easy. Ideally I would watch the waterfall and try to peak a station visually. Easier said than done.
I ran my 20A LiFePO4 DEEP into the cycle and it held up beautifully. I have a Bioenno 1503CAR for charging on the go. It helps to recover charge but won’t fully recover the charge on a short drive. The way to go is probably switching between 2x20Ah, or just a 50Ah cell.
It’s a fun way to get out and play on the high bands. Give it a shot even if all you have is a FM rig and a small beam. If nothing else use an all mode receiver (SDR is a great way to go) and monitor the high bands during a contest. It’s a good way to hear HF-band levels of activity on VHF+ and you might get motivated to join in.
The current explosion of HF weak signal mode users, coalescing primarily around FT8/FT4, has caused a bit of a rift in the ham community. I don’t think the rift is that big, but the rifters are pretty vocal in telling other hams how much they don’t belong on the air.
I intended to formulate a Pro/Con list, but I don’t want this to be a contest (or con-test). I also don’t want to explore the negatives. Plenty of people are doing that 24/7 and somehow seem to enjoy (?) it. This is a list of things that make each type of communication interesting and unique (for me). I’d rather look at it that way because that is how I feel about it. I want to enjoy all that ham radio has to offer. That requires being open to what is positive about every opportunity.
So here’s what I find attractive about FT8-style* operation:
The Analog Internet Nexus. In conjunction with PSKReporter, RBN, and tools like GridTracker, it provides a near-real-time propagation indicator. I can set up for a few CQs, check PSKReporter, and see where I am being heard, with my relative S/N. Along with showing me where I might expect a reply, it gives me an idea of the difference between what I am hearing and who might be hearing me.
Instant and visual split operation.WSJT-X makes setting split very easy, but only if you use the waterfall display. (I believe many users don’t, causing that crowding between 1300-1800hz). Shift-Click to position your transmit frequency in a different spot, and get out of the pileup of stations calling on the CQing station’s transmit frequency. Since WSJT-X decodes the entire bandpass, you can test this at will. 10 minutes with the WSJT-X manual will improve the experience 100x.
Constant Global Activity. It’s pretty shocking, actually. Day after day if I just looked at the CW or Phone sections of the HF bands they may look dead, or occupied mostly by big signals. Often there is a big hump on say 20m at 14.074MHz. In my experience it is unprecedented to have this type of activity acting as a global beacon. These digital segments are in use at all hours of the day and when the band opens those ops will be there.
Built for Low Power Ops. Being able to work down to -24dB is a great equalizer for lower power stations on less-than-spectacular antennas. I see all kinds of amazed reactions from mostly newer hams on QRP-focused boards like the Icom IC705 FB group, and I can only imagine how amazed they will be when actual good band conditions start arriving. I’ve worked 10,000km on 10W into a basic vertical antenna on FT8, during conditions like SF=75, SSN=15! No solar tailwind there. For reasons I will get into somewhere else, a non-directional antenna is really only sending a tiny slice of its output toward the other station. Being able to work deep into the noise floor makes the most of that tiny slice.
Perfect for casual operating. Letting WSJT-X decode while I am making dinner, or doing other chores, lets me come back and see what stations are in play at my station, on my gear, at what strength. I can take 15 minutes, scan the waterfall, and either chase a few stations or find a spot to call CQ. Obviously I can also do this for hours, but if I only have small gaps to focus on the radio I can still make contacts this way.
Good operating practices are rewarded. Far from being a “robot mode” FT8 gives the operator a lot of information if they are willing to look for it. It allows you to scan for momentary openings, dig out weaker signals, find opportunities to use split, and otherwise be creative with the information presented by the waterfall and the decode window. I recently made a few contacts to JA from Rhode Island with stations that showed up for less than 5 minutes, and then faded out. Tools like GridTracker and JTAlert let you watch for those stations in real time. I’ve come close to working deep into northern Canada (VE8) in this same manner. I’ve also seen the big Saudi or Kenyan stations about 20 times and never made the contact. Surfing the waves of fading/swelling conditions is a technique I learned on CW over 25 years ago.
*FT8-style means computer-assisted digital modes, like RTTY, even. 2FSK is still FSK, folks. Get over yourselves.
OK, that was a rollercoaster of unbridled optimism. I’ll now make similar points for analog modes:
The experience of listening to radio is one of life’s great joys. The key word is listening. I like quality in a QSO. Rarity and quantity have never been my game. I enjoy finding and working DX, but have never applied for or sought any awards. Listening to a quiet band for a weak but copyable signal (usually CW) just above the noise, replying to a CQ, and having a QSO (no matter how short or perfunctory) is a real pleasure. I’m not too hung up on where that other station is.
The Social Component. I have worked plenty of stations, mostly SSB, where the QSO is call, report, name, QTH, and 73. Nothing wrong with that. It’s not much more of a proof of concept than a FT8 contact, but you are making verbal/code contact. Neat. Occasionally though I end up in a real rag chew, with a personable operator, and it is a great experience. I have to make sure I am in no hurry, because I have had a few that ran for a long time. That is ham radio delivering on what I would call the classic roots: Two or more operators having a chat. Lovely.
A true leisure activity. My process of slowly scanning a section of a band, giving even the weakest signal a chance, tweaking my rig’s controls in an attempt to pull that signal out of the noise… it takes time. I might make one contact in an hour. I might make none. I have done some salmon fishing, and it is similar. My salmon fishing mantra is “it’s fishing, not shopping”. If you don’t enjoy the process of fishing you will be having a lot of bad days. If you have a catch, that’s great, but you are still fishing.
Skill Development. The skills necessary to operate successfully on the ham bands are still best, IMO, cultivated with analog operation. Just the habits of ensuring your frequency is clear, or listening to and identifying neighboring stations, or learning the band plan and using it… they pay off whether you are talking to someone on 2M simplex 500 yards away, or making an APRS contact through the ISS, or bouncing a signal off the moon. It might be analogous to driving stick shift. I think you get a better learning experience when you engage the fundamentals as completely as possible.
So that’s a quick, stream of thought run through of how I see the allure of both “new school” and “old school” ham radio. It’s all out there to be done, and it’s all good. I hope to see or hear you on the bands. Pete N1QDQ
This post is an attempt to bring my thoughts on the future of ham radio into focus through the lens of computerized digital modes. Last week I poured out a lengthy brain dump regarding digital modes, specifically FT8 and it’s associates. Three posts ago I went on about the evolution of communication modes. What I am focused on today is how radio hobbyists have embraced (or fought) the march of technology.
When radio was born the primary technologies being leveraged for more reliable communications were output power, antenna design, and modulation modes. That this is a fair description of the challenges faced by radio operators today is a testament to how strong the foundations of radio communications are. Just over 120 years ago Marconi was giddy at sending a coarse unmodulated signal across the English Channel. About 2 years later he sent a Morse Code “S” over the North Atlantic and it was received. From that primordial ooze advances in radio technology have been a succession of technological refinement and hybridization. Better tubes led to early solid state devices, led to (begat!) better solid state devices, led to the microprocessor and so on.
And that is how it should be. Most hams today use high tech in at least some part of their signal chain. The lack of enthusiasm for drifty VFOs and heavy transformers bears this out. Some of what I see in the commentary from today’s “old guard” is essentially a semantics debate, without the debate. Some want the technology used only inside their transceiver, but not “over the air”. Some are fine with one digital mode such as RTTY, but not another like FT8. Both employ a form of Frequency Shift Keying (FSK) and both rely on a machine to encode and decode text messages. This concept of using machines to do what the human body can’t is as old as the Stock Ticker. In the case of Radio Teletype (RTTY), could you learn to decode a two-tone encoding scheme by ear? Yep. Could you do it at RTTY speeds? Nope. We utilize a machine. That machine is now primarily a computer.
RTTY was first an analog process which gradually became computerized. Over the years the mechanical devices became museum pieces. One reason is electromechanical devices are entropy attractors. The wear out and break down and require mechanical repairs. Maintaining them means ready access to parts and service documentation. Certainly there are operators of mechanical RTTY terminals on the air, but they are in the minority (and I’m being generous). The era of “no serviceable parts inside” has mostly won the day here in the 21st Century. That’s a fact. I saw the transition from analog to digital firsthand as my father and grandfather both made their livings in electronics.
From the 1950s through the 1970s my grandfather owned and operated a TV and Appliance shop. He sold and repaired TV sets and radio consoles. His world was one of SAMS Photofact and a tube caddy and kept those TVs humming with his experience and some simple test equipment. The day the new TVs came with no service manuals he started to close his shop. That was almost 50 years ago. He saw the writing on the wall, and his mentality was fixed on keeping those sets in service. He was a product of the immigrant experience during a global depression and great scarcity. You did not throw things away. You repaired them until they were more valuable as parts, which you used to repair another set. The era of disposable consumer technology was his exit ramp from the business. He never changed. The world did. Far from being a luddite, he was an early adopter during the birth of technologies we take mostly for granted today. From the 1930’s onward he was right there jumping in on the birth of electrification, radio, television, and photography. He was my ur-geek.
As a child of a very different time I have been free to live in a world of unbridled futurism. I came of age during a great social awakening with social and technological changes happening at a blinding pace. I wasn’t so much dreaming of the future as I was living it. The space race fascinated me the way kids today get into dinosaurs or pokemon or whatever. I’ve been using actual computers since 1978. Before that I learned to do four function math on a Heath-Kit Hex Programming Trainer with NIXIE tube display. All I have seen is a steady drumbeat of miniaturization, automation, and leaps in electrical efficiency. I type this on an ultrabook weighing about two pounds and it the performance is fantastic. It draws about 1/50th of the power of my first PC-XT. The USB chip has more processing power than that 8088 had.
See, I’m digressing. I think you get the point. I will now focus!
My concern about the future of the technical evolution of ham radio has to do with the resistance to technical advances by some of the loudest voices in ham radio. And I do mean loudest. I like big antennas and I can not lie. You other ops can’t deny... But there are other ways to get the job done. In the case of FT8 we implement commodity computer hardware to expand the usable dynamic range down below what can be done with the human ear. This is not even all that high-tech. It is actually an extension of rather old tech, adapted to low cost CPU hardware.
Today’s hams largely operate in an early 20th Century manner, using 21st Century devices. We are often using a computer to emulate discrete component technology or even pure analog technology. That computer is often a “black box” running code we don’t understand on devices we can’t physically interact with. Most of this computerization isn’t a breakthrough, it is “re-platforming” of existing tech. While a boon to the operator it doesn’t seem to be equating into higher tech knowledge among the ham community. A survey of our publications, chat forums, and social media platforms show a continued focus on what should be Radio 101 topics: basic antennas, basic tuned circuits, basic inductors, the trans-match, the audio signal path… Yet I continue to see new hams struggling with the difference between rig control and audio, AC and DC, the concept of an IF, simple voltage/current concepts, and so on. One reason may be our teaching tools haven’t caught up with the pace of technology. Three-inch thick manuals in an age where bookstores are extinct might not be the way to get it done. #jussayin
At some point the practices and frameworks need to advance. We are doing ok, but we need to do better.
The Finale: I understand this is bordering on TABOO, but I’ll close this post with questions that I hope sum up my outlook on Amateur Radio as it waddles into the 21st Century:
Do our current band plans look like what we would draw up based on the technology we have at our disposal today?
As well, do our current band plans create a chilling effect on the adoption and implementation of new technologies?
Are we so anchored to the past that we have limited our ability to reach forward?
Can we create better technical standards, better education materials, and move toward better informed hams who can help move the pursuit forward and step beyond appliance operation?
I’m not pointing fingers (maybe a little). Those are questions I often ask about myself. I am largely an appliance operator. I build a few kits when I have time, make my own cables, build basic antenna systems, and am dedicated to self-education. I lean on a foundation of electronics basics and I want to learn more. But I also want to learn better.
I am using the FT8 discussion as a backdrop because we should be able to conceptualize how important decreasing the power and antenna requirements for ham radio is to the survival of the hobby. It is democratizing, and allows the ham radio experience to be enjoyed by the many. It also leans on tech that a 21st century ham takes completely for granted. If anything the challenge for today’s hams is adapting to the use of older tech that is used virtually nowhere else. The RS232 Serial Port is a great device, but try finding one on a modern computer. The urge to learn the technology is as strong as ever in the next generation of hams, we just need to lay a functional understanding of radio tech over that urge. That is difficult if the tech we are teaching and using is not current.
PostScript: I don’t see modes like FT8/JS8 as an end. I hope they are the foundation for more versatile and robust modes to come. We will always have SSB and CW and modes like RTTY. But unless we can get behind what the future holds we run the risk of being a bunch of radio-wielding Civil War reenactors. And one day we might show up to the battlefield and see a big CLOSED sign. Nobody wants that.
My first HF transceiver was a Ten Tec Triton IV with analog dial, followed by a TT Argo, A Yaesu FT101, and then one of the original, “shack in a box” radios, the ICOM IC706 (and later a MKIIG). For reasons mentioned in the previous post on this blog I moved on to running a Yaesu FT-857D, a FT-817ND, and an original FT-817. That gear, along with an assortment of V/U/SHF equipment for VHF contesting, and various FM HTs, was the basis of my experience with transceivers. I got to know what I liked and what I didn’t. The Triton IV was the most fun CW rig I have ever used. The receiver was easy on the ears, the QSK was fantastic (like listening to yourself on receive), and it was fairly portable. The IC706 rigs were more versatile, covered more bands, had more power, and included at 20/70cm all mode. And it wasn’t a bad all-mode. After seeing my gear pile dwindle to almost nothing I started putting together a new station. I was looking for something fun and portable and found myself looking at the uBitx. I worked up one kit but just felt like it was not going to handle what I wanted to do. Then Xiegu released their G90 and that radio got me back on the air for over a year. It’s a great rig, but it came with the question of what antenna to pair it with?
Having used wire dipoles and a few commercial multiband verticals for fixed operation, and hamsticks, base loaded whips and other compact designs for mobile use, I had something to refer back to. My experiences with those mobile antennas was not great. Yes they work. But no, they are no comparison to a full size antenna. I used those in both fixed and mobile setups and I was happy for any contact I could make. To be honest hey were not good performers on either transmit or receive. Once band conditions improve you will be able to regularly work some sweet DX at 20W into a 20M hamstick on a mag mount. Now is not that time. If you can’t put up a perfect antenna, at least try for the least-bad antenna you can manage.
It turns out that while I was off not paying attention to ham radio equipment there has been an explosion in “compromise” designs like end fed wire antennas and they can be built/purchased to suit anything from an altoids-tin rig to a legal limit linear. The development of these antennas revolves around two fundamental designs: A half-wave radiator with a 49:1 un-un at the feedpoint; or a 9:1 balun feeding a non-resonant wire. In practice the use of a counterpoise is either unnecessary or misunderstood. From an optimal antenna standpoint these designs leave much to be desired. The matching unit is being asked to make a large impedance transformation into a rather blunt radiator, without the typical array of ground radials or even a counterpoise of any kind. However, from a real-world standpoint these designs are proving to be both effective and easily erected while also being cheap to build. That is rare.
After perusing many different designs I purchased the PAR 402010 Trail Friendly. It is advertised as covering three popular bands with no ATU, and it is light enough to be supported by just about any support. This is a design antenna with a history of being made by several builders and Vibroplex now markets them with the PAR branding. It features a 41′ lightweight insulated/stranded wire radiator with a 40M trap to make it resonate on both 40m and 20m, and it will also load on parts of the 10m band. The lightweight build still feels sturdy, and has proven durable over a year of regular use. The tip of the radiator can get mashed up a bit, especially if you have a mast collapse. Note my use of a heavy wrap of electrical tape at the tip of the mast. It helps with setup and fits in the collapsed tube.
About that mast… (12M Spiderpole Mini-Review Alert) At the same time I was searching for antennas I found another member of the Vibroplex line, Spiderbeam, and their 12-Meter Spiderpole. Often nicknamed “the beast” It’s built like a tank and can hold up much more than this little low-power wire vertical. Interestingly they do fit like they were made for each other. “The Beast” isn’t a backpacker pole unless you are a glutton for punishment or take your Cross-Fit habits onto the trails. It isn’t terribly compact, and it isn’t light. What it is is a borderline overbuilt 41 foot weatherproof antenna support.
The Spiderpole is overkill, a luxury, though a versatile luxury at that. It is a big, heavy telescoping mast and needs to be well secured at the base. It has more wind load than I guessed and exerts a lot of leverage on that base section, so you want it to be well secured while avoiding hard points where the fiberglass tube wall could fail under a sudden or heavy wind load. The upside is you get a 41′ vertical skyhook. Nice. It also shrinks the footprint compared to what you need for a sloper or inverted vee and allows you to work where there is no overhead support. I am surrounded by beaches, so something like this lets me operate from more locations and not be limited by the presence/absence of a large tree(s) and I create less of an attractive hazard for lookie-loos. It appears to be a law of physics that as soon as you put up an antenna some random mammal will walk directly into it within 5 minutes. All you can do is pad the odds in your favor.
I was curious how this antenna would perform, especially compared to a 9:1 unit I had built and used on this same Spiderpole support. Mine is the basic trifilar design over a T200 core. The 9:1 works, but I always feel like I am working “up-hill” with it. That perception is based on ability to work stations I hear, and the signal reports I receive. There are worse options than a 9:1 into a chunk of wire sized to a convenient non-resonant length, but it feels very lossy in operation. When I first rigged the PAR I had my doubts. Rated at 25W SSB it isn’t much to look at. The matching unit is smaller than a fun-sized candy bar, the wire looks like overbuilt dental floss. Once I attached it to the Spiderpole and got it fully extended the ultralight wire It seemed out of balance being supported by “the beast”. Happily I was more than surprised at how well it performed. I observed much more parity with the stations I was hearing and working and logged several nice stretches of contacts on both FT8 and SSB. I was using it with both a Xiegu G90 and a Yaesu FT-991A, and aside from needing to watch the power output it did what it says on the tin. Three bands, no waiting. I don’t hesitate to set this up for a quick evening of casual operation since setup and take down require about 10 minutes each.
Here it is lashed to a deck railing in my back yard (or “garden”. You know who you are). If I was expecting gusty conditions I would have a 4-way support at the top rail and the base. In calm conditions the bongo ties hold up just fine. Just use as many as you dare. This thing puts a lot of stress on the support system.
Technical Aside: These end-fed matching devices are indeed lossy. You don’t need to break out a calculator to know this. All you have to do is look at the designs for different power ratings. The size and number of the ferrite toroids (typically 43-Mix) need to be increased to withstand the increased field density of each higher power rating, and the heat that comes with it. A good portion, perhaps as much as 30%, of the power making it to the matching device gets siphoned off as resistive/heat losses. [tl/dr YOU ARE MAKING HEAT NOT ERP] But hey, you know the setup is a compromise going in. That compromise is lower overall efficiency in exchange for ease of setup and portability. I found that going from 5W to 10W output caused a sizeable step change in the contacts I was able to make, but that is to be expected, since my ERP was probably going from 3W to 7W. Certainly you can make a lot of contacts with this antenna, but you will probably be be several dB down from where you *might* be on a more efficient antenna system. The upside is that you can get on the air quickly with not much fuss, which translates to more time operating and less time reading long winded blog posts. But I digress.
One big question with “the beast” is how to support it, and one of those lightweight drive-on flagpole mounts is not likely to get it done. I currently use a phalanx of bongo ties, woodworker clamps, ratchet straps, and U-Bolts. None of them are perfect but I can lash it to a variety of improvised bases. I’m thinking a 36″ tubular support welded to a 2″ trailer hitch is about what it would take to have real peace of mind with this thing while operating car-portable.
Wrap Up: My feeling about this antenna has done nothing but improved each time I deploy it. I feel like this particular design gets overlooked. That’s a shame because it is a solid performer. It hears very well, is easy to tune, and I am always surprised at how well it works. We can hope all we want to have a low loss resonant radiator over a dense field of copper radials, or a big dipole/doublet/windom/curtain a half wave up on solid supports, but it seems that what many/most hams typically need is a way to get on the air under sub-optimal conditions. We also want to be able to actually operate once we get set up. What I would love to see is a 200W CW Rated version with the same 41′ design. Right now I guess I have to build one. Vibroplex has a potential two-fer on their hands if they can match a 41′ triband wire vertical to their affordable heavy-duty 12m Spiderpole. That opens it up to running CW or digital/RTTY at a full 100W and having a solid safety margin at the feedpoint.
I hope this was informative, or at least I hope you had a good nap. 73, N1QDQ
Posted onApril 16, 2021|Comments Off on A quick note about my shack, and why..
I’ve been licensed since about 1992 and never had a “real” ham shack. My home shack was usually an extension of my desk area, and never a classic, photogenic, radio room with awards on the walls. As well, I have never owned a tower and have used either wire antennas or trap verticals. I had a good sized lot but I was losing trees to various blights and my spouse is…. antenna adverse? She has not problem with radio activity, but having a nest of wires on display is not her idea of a good time. We lived in a valley surrounded on three sides by basalt bedrock and till. If you want a RF absorbent QTH, move to the bottom of a valley surrounded by iron ore. Good times. That lays the basis for my choices, and as a result I did a lot of mobile and portable operating.
As I am closing in on 30 years as a ham I have had burst of activity and have been active sporadically for the past 15 years. I was living between two QTHs for the past 10 years and didn’t have a good spot for a permanent antenna at either. Plus, I was planning on selling a house and didn’t want to put something up and then have to break it all down again in short order. That property had too many scars from previous antennas already!
Even though I didn’t always find time to operate I always had at least one transceiver and an assortment of shortwave receivers. At the new QTH on the Rhode Island coast I have a smaller lot, and am planning some landscaping and construction. That is a bad time to start putting up permanent antennas. Thanks to a host of portable antenna options that didn’t stop me from finding a way to get on the air. Previously I had been operating on an Alpha-Delta DX-EE multiband dipole mounted in an attic space. Aside from being a bear to tune to resonance, It came with a host of RFI issues, and attic spaces make for poor antenna locations. I ran a Bencher Low Pass Filter which knocked down the worst of the RFI I was generating. It worked, and I made some good contacts on it, but overall I consider it a last-option solution. Again, an antenna surrounded by a RF absorber.
As I rebooted my shack setup and started researching gear I saw that a forest of QRP/Portable/Packable antennas and antenna supports had sprung up over the past decade. That piqued my interest in a major way. The idea that I could operate portable and not have to make huge compromises in antenna performance, or be limited by the ability to string dipoles in a forest canopy, was and is very attractive. I jumped in and built or purchased several pieces that allowed me to get on the air with a better signal, even if I was still operating out of Pelican cases at home. My plan is to cover a few of these choices with an eye on how I planned to deploy them, What I learned from deploying them, and my impressions of their performance. To say I am not being paid is an understatement. If I was ever to be endorsed or get a product to review it would be in boldface at the top of the post/video.
Here’s a partial list of the gear I am hoping to cover, in no particular order, except that I am reviewing the PAR 402010 TF first…
PAR Trail Friendly 402010 (Vibroplex)
PackTenna Mini EFHW
Homebrew 9:1 End Fed Wire System
Homebrew 49:1-ish EFHW System
Spiderbeams 12M Spiderpole HD
DX Commander Expedition
Wolf River TIA Max
Chameleon MPAS Lite
Thanks for looking, and I hope I’m able to add something useful to the conversation around these popular antenna systems. My goal is to try and knock one out each week, and we will see how that goes.
Best 73, Pete Brunelli N1QDQ
Comments Off on A quick note about my shack, and why..