antennas

The Casa Easton Antenna Test Range has been busy the past few days. About 2 weeks ago, I discovered KJ6ER, Greg Mihran’s, PERformer (Portable, Elevated, Resonant) antenna. Greg describes the antenna in spectacular detail in a frequently updated document. He has extensively modeled the antenna for 40M through 6M. I built mine for 20M through 10M, especially for use with my QMX transceiver.

Bottom line: This one’s a KEEPER! Advice: Greg has a DONATE button as part of his fine article. I suggest using it to recognize his good work.

My problem with elevated vertical antennas

Several hams, WB3GCK, Craig La Barge, and WK4DS, David Saylors, in particular, talk about using elevated antennas atop poles mounted on the back of their trucks. They use them with tuned raised radials and they have great results at QRP power levels.

I’ve tried elevated antennas and raised radials on my own antenna test range and haven’t yet matched their results. However, I’ve not had good measurements for the various components. Guesswork resulted in functioning antennas, but not in the kind of results Craig and David report.

Until…

The KJ6ER description brought it all home for me. KJ6ER, Greg, describes his modelling, includes several tables showing measurements, and offers construction ideas. All are great starting points.

Results

I measured with a NanoVNA, and then with WSPR. Antenna lengths were tuned for lowest SWR in the CW portions of the bands, usually the QRP hailing frequency. I frequently use WSPR to discover an antenna’s potential, and treat WSPR results as a “possibility,” never a guarantee. Each of these WSPR runs were mid to late afternoon in the US Eastern timezone, with each run for 6 minutes. Solar Ham showed this as a typical propagation day, no solar storms.

These are the lowest SWR results I’ve seen in any of my testing.

Band	Radial lth	Radiator lth	SWR	Impedance
10m	80″	114″	1.031:1	50.7Ω
12m	96″	124.5″	1.045:1	51.1Ω
15m	120″	143.5″	1.027:1	48.7Ω
17m	149″	163″	1.049:1	49.7Ω
20m	198″	207.25″	1.041:1	48.1Ω

Compared to other Casa Easton Test Range antennas

Long ago, I crawled around burying 18 radials in the grass. I use that field with either a Wolf River Coils antenna or with Hamsticks, all sitting atop a low tripod. They’ve produced ~almost~ continental coverage, and always enough capability to reach hundreds upon hundreds of mid-continental POTA activators. SWR with those configurations run between 1.3:1 and 1:7:1, never lower.

My vertical dipole, A DX Engineering Transworld 2010 (TW2010) has also offered reliable mid-continental results, and maybe longer reach than the verticals atop the radial field. It’s advantage is quick setup, even tough it does need more than the usual amount of coax for impedance balance … and SWR in the 1.2:1 to 1.4:1 range. The difference is so slight (in actual listening) as to not be noticeable. Knowing what I know of it now, I shouldn’t have spent that much on it.

DIY-built EFHW and EFRW inverted Vees have almost always performed better than the verticals over the radial field. I’m continually playing with variations and am usually pleased with how well they work, especially the ease of changing bands.

Which brings me to the PERformer. KJ6ER, Greg, shows his models demonstrating efficiency factors about 30% better than most of my other antennas, and some directional front-to-back gain. So far, I’ve had delightfully solid results and at least one contact well beyond the normal range of my other antennas, possibly confirming the directional gain. A too-short session yesterday brought a quick string of POTA QSOs at higher than usual signal reports. I’m not quite gushing yet, but I have thanked Greg and remind you to push his DONATE button when you see the same results I have.

Time will tell. (Hey Alaska, are you hearin’ me?)

Bonus material

KB9VBR, Michael Martens excellently describes details of his build and his results below. Pay particular attention to the last / summary section.

After taming the Hamsticks, I turned my attention to effectiveness. How do these antennas compare to another in my collection?

Contestant 1: Hamstick verticals

Contestant 2: DX Engineering TransWorld 2010

P.S. KA3DRR, Scott Morrison, drags his TW2010 around in a wagon he calls Land Rover One. He’s not one of those strong healthy young males who grumble about the difference between a 9 ounce radio and a 14 ounce radio. 🙂

The competition

Some of the YouTube ham personalities review antennas by describing them in manufacturers’ terms, showing how they are assembled, and usually taking them outside somewhere, hooking up 100w SSB transceiver and making a few calls. “See, it works!”

Of course it does, almost everything does. If K0KLB, Kevin Behn, can loads up his grain auger or hay wagon at QRP power and make contacts, almost any other antenna “works.”

I’m more of a data person. Fifty years in the IT business, and the delight of working many of those years in a research laboratory, does that to a person. I like data to support conclusions. So, I use a ZachTek WSPR Transmitter to check out antennas. WSPR is Weak Signal Propagation Reporter, a network of radio stations that listen for specifically coded signals and file them in a searchable database.

For these tests, I set up 12 minute runs for each antenna in midday on May 27. Midday is not optimal for any particular band, so results don’t indicate the best that can be achieved during peak propagation periods. But, the results do show relative performance of each antenna compared to another. Yes, there are those who say propagation conditions vary constantly, and I agree. Running 6 tests as close together as possible is the best that I can do to mitigate constant change. I collected results using the wspr.rocks site, one of several that collect WSPR data.

There are three rounds of tests, each individual test running for 12 minutes:

• TW2010 set for 20M vs a 20M Hamstick with a radial field in the grass
• TW2010 set for 15M vs a 15M Hamstick with 3 loose radials on the ground
• TW2010 set for 10M vs a 10M Hamstick with 3 loose radials on the ground

	Spots	Avg SNR (dB)	Max KM	Spots @ Max
TW 20M	190	-17	3808	1
HS 20M	121	-18	3808	1
TW 15M	103	-17	6466	4
HS 15M	88	-18	6466	6
TW 10M	72	-18	4251	3
HS 10M	50	-20	4213	4

Counting spots, the TW2010 performed better than each comparable Hamstick. That’s not really a surprise since well tuned dipoles usually outperform 1/4 wavelength verticals. The margins for numbers of spots are 35% better on 20M, 15% better on 15M and 31% better on 10M.

As for reach, the Maximum Kilometer distances are almost identical, with outliers for both antenna versions. At max distance, the Hamsticks have more hits which seems a disparity from the overall spot counts. The SNR averages are only 1 to 2 dB difference, with the Hamsticks showing a stronger average. So, why is it they have a lower number of spots? Tis a puzzlement…

For the graphic record, here are 6 maps corresponding with the 6 runs.

Turning from data to reality, I’ve made 6 QSOs from my Florida QTH to Oregon: 1 with the 20M Hamstick, 2 with the 20M TW2010, 2 with the 20M Wolf River Coils 17’whip, 1 with the 15M Wolf River Coils 17′ whip , most on different days, different times, different RSTs. so, yes all of these antennas “work.” 🙂

In the end, a subjective question remains: Is it worth paying about 6 times more for the TW2010 than for my collection of Hamsticks?

UPDATE 10/20/24: Two recent events happened recently with the TW2010.

• A QSO with Paul Butzi, W7PFB out in the woods in Washington state. I’ve been chasing POTA for a long time, and WA is a LONG way from FL. Paul and I made a faint QSO, via the TW2010 and my QMX on my end and 10W into a a Chelegance MC-750 on his end.
• The next day, frequency agility worked very well on the TW2010 as I made QSOs on all of its bands, 10m, 12m, 15m, 17m, 20m. Yes, I have Hamsticks for each of those bands, but band switching was easier with the TW2010’s “U” plugs, even faster than the Hamstick quick disconnects. Good propagation days and beautiful fall weather brings out POTA activators on all bands.

Neighbors near me in this HOA location are very tolerant of my “backyard portable” vertical antennas. The antennas are not obtrusive in appearance, use little space and work reasonably well considering they are not multi element yagis on a 60′ tower.

For some time, I worked with Wolf River Coils verticals on 40M, 30M, 20M. I use them on a tripod sitting over a radial field of 18 radials, each about 16′ long. While reasonably effective, changing bands is really fussy. Get out the NanoVNA, adjust the coil, adjust the whip length, repeat until good enough for the transmitter to be happy. Wash, rinse, repeat…

Some will suggest a multiband vertical instead. Even though I had a good experience with a fellow ham’s 6BTV, I’m not willing to live with its equally fussy tuning and losses, esp when it’s hidden inside a flagpole and every adjustment is a sequence of: lower the pole, uncover the antenna, adjust, re-cover the antenna and re-raise the pole, quite an ordeal.

So, I had the idea that I could acquire a collection of Hamsticks (40M, 30M, 15M, 10M) tune ’em once, install quick-change adapters on them and have band changes within seconds. BZZZZZZZZZT! A couple of them worked OK above my radial field. The others wouldn’t. We read frequently that more radials are always better, and Callum tells us that up to a certain point that’s true.

More radials: It Ain’t Necessarily So

Gershwin tried to tell us… I spent a lot of time yesterday trying each of these HamSticks in different configurations. My goal was to discover the configuration of each with the lowest SWR, as indicated by a NanoVNA.

Of course, these measures of goodness are simply SWR numbers from a test device. On air performance is the real test. I’ve already made on-air contacts with all of them. My next round of measured testing will be WSPR runs.

Till then, this chart sums up my test results. I’ll be using he bold entries to make band changes fast, easy and tuner-free.

Band	No radials	3 x 11 ft	3 x 33 ft	18 x 16′ field
40M	3.65	n/a	1.718	1.387
20M	3.52	n/a	1.082	1.085
15M	1.718	1.139	1.572	2.132
10M	1.595	1.483	1.583	1.656

If you have been following along with my antenna experiments, you know that I always work with temporary outdoor / field antennas and have been searching for a solution I can make more permanent. It needs to be always available, and frequency resilient.

The idea that I’ve harbored for a long time is a multi-band antenna in the attic. Never mind that certain people don’t want me climbing around in an attic which is likely more complex than the simple one we had “up north.”

The very successful EFHW became the ideal candidate. It performs well, even if its signal strength is about 1/2 an S-unit lower than my best verticals. I remade the original with heavier, more durable, wire and field tested it several days. Like the original, it performed well, with no need of a tuner, on 40M, 20M, 15m, and 10m. All I needed was someone to hang it in the attic.

After a good bit of searching, a good guy known as “The Village Tinker” suggested a certain “low voltage” installation firm (cable TV, ethernet, etc. ) They agreed to do it for the simple price of a one hour service call. A couple of guys came out and I described what I wanted, emphasizing that as high as possible was my desire. I handed them the antenna, complete with the 49:1 transformer in a box, and a simple center hanger that I had been using outdoors. They had the job done in about an hour and we exchanged a check for a receipt.

Results: the 4 band antenna that needed no tuner is now a 4 band antenna that needs a tuner for 3 of those bands, doesn’t hear very well, and has an S-5 noise floor! Sigh!!! I have made a few QSOs with it. The signal reports are lower than with other antennas, and the noise, apparently from other things running through the attic, makes it uncomfortable for listening and decoding CW. It certainly will not be an everyday antenna, maybe an alternative on rainy days.

What happened? I asked one of the installers to show me, on a overhead picture of the house, where the antenna ended up. It wasn’t as high as I expected, nor did it run quite as I expected. By that time, we were out of service call time, and I didn’t ask that he go change anything. What had really happened? He put the center hanger, a simple little plastic triangle with a few holes, as high as he could (not very)… when he came to it … If were installing it, I would have scooted the hanger along until I could get it up to the peak of the roof line. Because he didn’t use some of the distance going up, he had more wire left at the far end, and simply routed it around a corner. The antenna is not the inverted vee I wanted, but a bent horizontal that’s not very high. That speaks to the “doesn’t hear well” aspect. The difference in resonance points and in ambient noise floor is most likely due to the nearness of all the other kinds of wires and ducts in the attic space.

Should I ask for another service call to relocate it up to the top of the roof line? With the unpleasantly high noise floor, I think not.

Bottom line: It is a reasonable 3.5 band antenna. It resonates OK on 40M, very well on 20M, OK on 15M, and can be coerced for 18M, and NO-GO on all other bands.

I launched it in the backyard in the usual inverted vee fashion of some of my other wires. Measurements with a NanoVNA produced these SWR values:

It becomes yet another addition to my antenna graveyard / spare parts bin.

This follows the EFHW Fail article. There are a lot of ways to configure an End Fed Half Wave antenna. The earlier article explored a variant that sort of works, but not as well as expected … and certainly not as well as this one.

This EFHW variant is very common, a 49:1 transformer, bridged with a 100pf capacitor, and about 67 feet of wire. It is designed for 40M and higher. Once assembled, the wire is cut to a length that produces the desired resonance points, and there are several with this design.

About design… There’s a well known chart for Random Wire Antenna Lengths. It shows all sorts of lengths to use for antennas that are (1) random length, (2) are not resident on any band, and (3) always require the use of an antenna tuner. There must be some good rationale for such a thing, but it befuddles me why anyone intentionally always wants to use part of their RF output to warm up coils in a tuner. Aren’t antennas resonant at the desired frequencies a lot more efficient? OK, let’s set that aside… the chart is also, maybe unintentionally, helpful for offering the good lengths for EFHW antennas that have multiple natural resonance points. Just use the parts of the chart marked in red that the chart labels “Lengths to avoid.” They are EXACTLY the ones we want.

That blue oval is my addition to the chart, and the starting point for this antenna’s length. The actual length, trimmed as I like it, is 66 feet, 5 inches.

The design is so popular that a number of hams sell kits for building a 40m version. These are the people willing to gather all the parts, package them nicely for us, and save us the effort of finding each individual piece. Just try buying one BNC connector and paying shipping for it, then the wire, then the capacitor, then the torroid, etc. etc. One of those kit packagers is Jason Oleham, KM4ACK. His kit sells for about $40 and is often out of stock because of its popularity. The KM4ACK EFHW kit was the starting point for my EFHW adventures. It worked better than many other wire antennas I experimented with over the past year. As advertised, it is naturally resonant on 40M, 20M, 15M and 10M. With careful trimming, I made mine happy to work very well in the CW portions of those bands. BTW, it works with NO counterpoise, and is not sensitive to feedline length.

Below are NanoVNA screenshots for 3-20Mhz, 40M, 20M, 15M and 10M. In all the charts, the marker shows the QRP hailing frequency in the CW portion of the band.

Interestingly, the tuner built into the Penntek TR-45L can tune this antenna on 80M and 30M, but definitely not on 17M. I haven’t actually made contacts with the tuned results on 80M and 30M, but have on the other bands. I’m very pleased with the results, a good step toward frequency resilience for this HOA ham. Next, let’s see what it does when placed under roof.

Under roof update: My original idea was to use this successful antenna as an indoors antenna, in the attic space of our home. That didn’t work out so well. Due to a local prohibition against wandering around in the attic, I hired a wiring firm to do the job. With little antenna experience they installed it, but not as high as I wanted, and “folded” into a tortuous path. It’s a failure in any but the last-chance alternative.

Next, let’s look at a couple of WSPR runs for the bands I use most, 20M and 40M. I’ll get to WSPR runs for the other bands soon. In the meantime, I’ll mention that my first contacts on 15M and 10M with this antenna were TX and AZ.