From my inbox: CQ Burger King, BPL, solderless PL-259

Amateur radio plays a big part in this new Burger King ad.

 

FCC Denies ARRL BPL Petition. As this commentary from TV Technology notes, the FCC denied the ARRL’s that BPL systems include full time notching of amateur radio frequencies and an increase in the required notch depth from 25 dB to 35 dB. They also say, “While the Second MO&O isn’t good news for amateur radio operators, utilities seem to have lost their interest in using BPL to provide residential Internet access…and smart meters so it may have little real impact.” Let’s hope it stays that way.

Solderless PL-259. On the AMRAD mailing list, one ham writes:

Shakespeare has been in the marine antenna business since shortly before the discovery of oceans and they have a couple of bits of kit which you might consider for your ARES or Field Day bug-out box. They make a PL259 and a coax cable spice which go together with nothing but a knife sharp enough to cut the plastics and a pair of pliers. I wouldn’t try running the legal limit through these (the coax they fit wouldn’t like it either) but i have used the PL259 for up to 100-watt service and they have performed admirably.

They are kind of expensive at around $15 a pop, but they do look like quality parts and that they’d work pretty good in a pinch.

Putting up another antenna

When I got home from the Ann Arbor Hands-On Museum on Saturday, I called up my friend Mark, W8MP. I wanted to tell him about my contact with OG3077F, a Finn who has successfully worked all 3,077 U.S. counties. As it turned out, Mark has worked him several times. I should have suspected this. Mark seems to know everyone.

As we continued our conversation, he mentioned that one of his son’s friends had put up an antenna and that they were going over there to help him tune it up that afternoon, and he asked if I’d like to join them. Mark’s son, Brian, is KD8EEH, and his friend, Alec, is KD8RGP. To be honest, I was a little hesitant. I was kind of tired after walking home from the museum, but Mark twisted my arm a little, so I agreed to head over there.

On the phone, Mark suggested that I might want to bring over some coax and some other kinds of antenna-making stuff, so that if we needed to make modifications, we’d have the wherewithal to do it. So, I loaded my crate of antenna parts, my toolbox, my 100-ft. tape measure, and a spool of coax into my Mini.

When I got there, I found that Alec was way ahead of us. He actually had already set up a 20m dipole. One end was suspended from an old, now unused power pole at the back of Alec’s backyard. The other was suspended by a rope draped over a downspout.

The construction was actually quite ingenious. For the center insulator, Alec had drilled some holes in a small block of wood that provided both strain relief for the wires and a way to mount an SO-239 connector. I wish I’d taken a picture of it. The end insulators were made from some scrap plastic.

The Budwig HQ-1 center insulator is a great way to build a dipole

The Budwig HQ-1 center insulator is a great way to build a dipole

Ingenious though it was, I suggested that we might wan to rebuild the antenna with an HQ-1 center insulator (right) to make it more reliable. While we were at it, I also suggested that we use a set of HQ-2 insulators for the ends. Mark got the boys working on disassembling the current antenna and rebuilding it with the new insulators, and in a short time, it was back up in the air.

Because Alec had already routed the coax down to the basement, we all tromped down there to see how well it tuned. Yipes! It looked to be way long. So, we lowered it, shortened each side by six inches and tromped back down stairs. We were closer this time, but it still needed to be shorter, especially since we were tuning this for the phone portion of the band. We shortened it by another six inches, and bingo, this time we got a nice dip right around 14.25 MHz.

Flush with success, someone suggested that we might want to add 40m elements to the dipole. This sounded like a good idea to me, and I told them about the 30m/40m dipole that I have. After a little discussion about whether to use feet or meters to calculate antenna length (we decided on inches as my tape measure is ruled in feet and inches), Alec started scrounging around for some wire.

At first this looked like it was going to be a problem. There was one 28-ft. length, and a couple of other odd lengths, but it wasn’t clear that we were going to be able to make two, 33.5-ft. lengths from the pieces we had. We finally did figure it out, though, and the antenna was lowered, and Alec attached these elements to the center insulator.

As it turned out, there were some convenient supports for these elements that allowed this dipole to be oriented nearly perpendicular to the 20m dipole. On one end, the boys used a tree, and at the other end, the wire was draped over another a downspout on the opposite side of the house.

We again tromped downstairs to check the resonance. Again, we were quite long. We lowered the antenna and shortened it by six inches on each end, then measured again. This time, the resonant point was just below 7 MHz. This time, we shortened the antenna by nine inches on each side, and the resonant point was just about in the middle of the General Class portion of the 40m phone band.

Of course, the proof of the pudding is in the eating, so we told Alec to get on the radio and see if we could make any contacts. Tuning around, Alec found a few stations working the Missouri QSO Party. He called a couple of them, and worked them on the first call.

At that, we called our efforts a success, and went upstairs to eat some take-out curry that Alec’s parents had gotten for us. Over dinner, we all patted ourselves on the back. I’m sure that Alec is in for a lot of fun on 20m and 40m.

Ads of note from the April 2013 QST

I couldn’t sleep this morning, so rather than just lie in bed, looking at the ceiling, I got up and made myself a (very) early breakfast. Whilst eating my eggs and cantaloupe, I scanned the ads from the latest QST. Here’s what caught my eye:

The TT1A costs $129, and that doesn’t include the 200 V power supply. Yipes!

  • YouKits (page 128). YouKits is offering a new kit this month – the TT1A two-band, two-tube CW transmitter. It’s very cute, but according to the YouKit website, it costs $129 (plus $29 shipping), and even at that, you have to buy or build a 250V supply to power the thing. Call me crazy, but I think that’s a bit much for a 4W transmitter, don’t you? I think I’d rather spend that money on the Funk Amateur SDR kit (see below). TenTec is YouKits U.S. distributor, but I don’t find this kit on the TenTec website yet.
  • Mosley Electronics (page 132, 153). Mosley has been making quality antennas for many years. In the April 2013 QST, they are running a very small ad on pages 132 and 153. I guess they have such a good reputation that they really don’t need a big ad. You’d think that I’d be more familiar with their products (since I’ve been a ham for many years), but I’m not really. Their ad prompted me to go to the Mosley website, where I found out that they not only made beam antennas, but verticals and dipoles as well. In addition to information about their products, there is information about antennas in general. I particularly liked the short article on “SWR-itis.”
  • Funk Amateur (page 147). A lot of amateur radio operators are funky, but “funk” in this case is German for radio. This German company is offering two kits: the FiFi SDR kit, which is a 0.1 – 30 MHz SDR receiver for $169, and a voice keyer kit for $55. Both prices include shipping to the U.S. I’m going to contact them and see if they’re going to be at Dayton. If not, I might just pop for one or both of the kits.

U-M ARC needs antenna ideas

W8UM

The University of Michigan Amateur Radio Club is celebrating their 100th anniversary this year. The recently reinvigorated club has a great station, W8UM, in the Electrical Engineering and Computer Science (EECS) Building on U-M’s North Campus.

The University of Michigan Amateur Radio Club is celebrating their 100th anniversary this year. To celebrate, they’re planning to operate a special event station from the Diag, an open space in the heart of the campus.

The problem they’re having are all the rules for such an event. For example, the event can’t be too noisy, even though it’s outside.

The biggest problem they’re having though is trying to come up with an antenna setup that the powers that be will approve. They can’t, for example, drive any stakes into the ground. Supposedly, that will damage the lawns. That rules out the 40m/20m inverted-V setup supported by the surplus fiberglass masts that we often use for these kind of temporary operations.

There’s also a rule that whatever structure is erected be no higher than eight feet tall. That also rules out the use of the fiberglass mast.

There are some trees near where they want to set up the station, but the grounds department have concerns about ropes in trees. That kind of rules out dipoles.

This morning, it occurred to me that we probably could use BuddiPoles and/or BuddiSticks. We could easily keep them under eight feet, and if operated vertically, they could be decent antennas. Using an insulated wire for the counterpoise should be safe enough.

I’d like to hear what you think, though. What kind of antennas have you used for this type of operation? Do they meet the restrictions these guys must meet?

Found my 20m noise source

About three months ago, I finally put up another 20m antenna—an end-fed, half-wave antenna. Right off the bat, I was flummoxed (I love that word) by the high noise level. It was nearly S9, obliterating all but the strongest signals.

I thought it had to be something to do with the antenna. I was not experiencing any noise on any of the other bands, after all.

As it turns out, though, the source of the noise is the laptop power supply. I had taken the laptop somewhere on Wednesday, and when I returned it to the shack that evening, I switched the rig over to 20m before connecting the power supply back to the laptop. No noise! When I plugged the power supply into the laptop, the noise jumped up to S9 again.

What’s really confusing about all this is that I don’t hear this noise on any other band. They’re all completely quiet. Like I’ve said before, sometimes 40m is so quiet that I wonder if the antenna is even connected.

At any rate, the last couple of days, I’ve been working 20m with the power supply disconnected, running the laptop off the battery, and the results have been quite good. This evening, for example, I worked several DX stations, including 6W/HA0NAR in Senegal.

Amateur Radio Videos: Velveeta, soldering PL259s, antenna polarization

Here’s a collection of ham radio-related videos that I’ve run across in the last week or so. I need to start doing videos. Anyone wan to help me out?

Velveeta? Really? Kraft is using ham radio to plug Velveeta cheese. It’s pretty cheezy (pun intended), but funny, too. Seriously, though, I hope not too many of you out there eat this stuff. If you need a recipe to make some “real” macaroni and cheese, I’ll post my recipe here.

PL-259 Connector Installation. Thanks to Alex, N3DER, for posting a link to this video on the Tacos mailing list. The video’s creator, Murray, W9EHQ, is very thorough and presents a very good technique for installing PL-259s onto coax. Lately, however, I’ve been using crimp-on PL-259s. Crimping the connectors is much easier than soldering them. Phil, M1GWZ, is also not sold on this technique. He notes, “I didn’t find the video entirely convincing. For a start, he remembered to put the plug cover on the cable before soldering the connector on. I’ve never seen anyone do that before.  :-)”

Yagi and Lightbulb Antenna – K0NR. Bob, K0NR, demonstrates polarization using a simple 2m dipole with a lightbulb connected between the two elements. I’ve done this demonstration down at the Hands-on Museum. It’s a really good way to show how polarization works.

How do you choose an antenna analyzer?

A reader recently e-mailed me:

In the past you told me you started with the Autek RF-1, and later moved to the Palstar ZM-30. I am finally getting around to thinking about purchasing an antenna analyzer, but I am stumped by the choices. In order of increasing purchase price this is what I’ve turned up:

How does one decide? Where does one go to find out the differences? Other than asking a fellow ham, how does one find out which one is the best antenna analyzer without paying an arm and a leg (unless the feature(s) so purchased are deemed worth the cost)?

Thanks! 73

He actually missed several other good choices:

  • Autek VA1 – $199. This is actually the antenna analyzer that I first purchased.
  • MFJ 259B - $240. This is arguably the most popular antenna analyzer on the market. MFJ has several other models with different feature sets.
  • YouKits FG-01 – $250. This is a very cute, little analyzer with a small graphical display. It seems kind of expensive, but the graphical display might be worth it.
  • Comet CAA500 – $450.

So, how do you choose just one from this list? Well, I think the first thing that you have to ask yourself is how you’re going to use the analyzer. If all you’re going to do is to check the SWR of your HF dipoles, then buy the Autek RF-1. It’s the least expensive unit, is reasonably accurate, and is small and lightweight, making it easy to use outside where your antennas are located.

Autek RF-1

The Autek RF-1 is inexpensive, and its small size makes it easy to use outdoors where your antennas are.

If you want to do some more serious frequency analysis, then you should be looking at the W4RT miniVNA or, if you have more cash, the Timewave TZ-900s. These instruments can help you do a lot more in-depth analysis of your antenna system. The figure below, for example, shows a plot generated by the miniVNA software. It shows the SWR of a multi-band vertical antenna from 3 – 33 MHz.

miniVNa display

For more sophisticated frequency analysis, consider the miniVNA. It uses a computer to generate graphs like this.

Some antenna analyzers do more than just SWR. For example, what sold me first on the Autek VA1 and then on the Palstar was that they also measured reactance. So, you can use the antenna analyzer as an LC meter as well. Palstar also says that you can use the ZM-3 as a low-level signal source.

Next, you need to consider what bands you’ll be using it on. Many antenna analyzers only cover the HF bands. That’s a bummer if you like operating 6m, or like to experiment with VHF/UHF antennas. A friend of mine bought the Palstar antenna analyzer after talking to the company at Dayton. At the time, they said that they were planning to come out with a model that covered 6m, as well as the HF bands.

Unfortunately, they never did come out with a 6m version, and he was sorely disappointed. He ended up buying a miniVNA instead.

Asking your fellow hams about the antenna analyzers they have is actually a good way to figure out what’s best for you. If you ask nicely, they might even let you borrow their analyzers or come over and show you how it works on your antennas.

Reading the reviews on eHam is also a good way to gather information before making a purchase like this. You certainly have to take the reviews there with a grain of salt, but if several reviewers mention a particularly good or particularly bad feature of a product, then it’s certainly something worth taking a hard look at.

If you’re new to the hobby, starting out small and working your way up might be a good strategy. You could buy one of the less expensive models and get used to how they work,  then sell it and make the leap to a more sophisticated unit. The way things are going, you should be able to sell your first antenna analyzer for at least 80% of what you paid for it.

Whatever you do, don’t fall victim to “paralysis by analysis.” Go ahead and buy one and start using it. This is a learn by doing hobby after all.

Choosing an HF vertical

Last week, an online amateur radio retailer contacted me about writing some blog posts for his website. One of the topics he suggested was “Choosing an HF vertical.” Here’s what I wrote this morning:

Choosing an HF vertical

For many amateur radio operators, a vertical antenna may be the only option they have to put up an HF antenna. They may, perhaps, live on a small lot, or they may not have suitable trees or other antenna supports from which they can hang dipoles.

Fortunately, there are many good products on the market. Unfortunately, there is some confusion about the different types of verticals out there. This short article will attempt to give you some guidance on how to choose the right vertical for you.

Trap verticals
Trap verticals have been around for a very long time. My very first HF antenna back in 1971 was a hy-gain 14AVQ. These verticals use “traps” that are parallel resonant circuits to electrically isolate portions of the antenna when transmitting on various bands. The traps make the antenna act as if it were a resonant quarter-wave vertical. For example, when the 14AVQ is being used on the 10m band only the lower portion of the antenna is active. When operating 40m, the entire length of the antenna is active.

Trap verticals need radials to operate effectively, and the more the merrier. Take this into consideration, when deciding whether or not to purchase a trap vertical.

No-radial verticals
In recent years, several manufacturers have introduced vertical antennas that do not need radials. GAP Antennas is one manufacturer that offers these kinds of antennas.

The manufacturers claim that these antennas are more efficient than trap verticals, and  many amateurs use them with good results. There are some drawbacks, however. They can be difficult to tune, and they do require mounting at some distance above ground. The reason for this is that they are, in effect, vertical dipoles and if the end of the antenna is too close to ground, capacitive coupling will detune the antenna.

Non-resonant vertical antennas
A third class of vertical antenna that is becoming popular is the non-resonant vertical antenna. An example of this type of antenna is the LDG S9v43 Vertical Antenna, although several other manufacturers also make this type of antenna.

One reason that this type of vertical antenna is becoming popular is that it can be used across a wide frequency range. The resonant frequency of this antenna is actually about 5.4 MHz. With an antenna tuner, however, you can use the antenna on all bands from 80m to 6m.

This tuner can be located in your shack, but for the lowest loss, you will want to locate the tuner near the base of your antenna. Don’t try using it with the internal tuner in your rig. On some frequencies, the antenna impedance will be quite high, and most internal rig auto tuners do not have adequate range to provide a 50-ohm match.

These antennas require radials. There is no formula to calculating the length of the   radials, but they should be at least 0.2 wavelength at the lowest frequency that you wish to operate.

We carry the entire line of LDG vertical antennas. The LDG S9v43 antenna is 43 ft. high and covers 80m – 6m, the LDG S9v31 antenna is 31 ft. high and covers 40m – 6m, and the LDG S9v18 antenna is 18 ft. high and covers 20m – 6m. All of these antennas use heavy-duty, telescoping fiberglass sections. The antenna is self-supporting, and because it’s very light weight, easy to install.

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I know it’s not a comprehensive guide to how to choose an antenna, but that’s not the intent. I also know that it’s a bit slanted towards the non-resonant vertical, but that’s the kind of antenna that the company carries.  Having said that, I’d love to hear your comments.

Ads of Note from the December 2012 QST

When I was a kid, I used to religiously pore over the ads in the Electronics Illustrated, Popular Electronics, and later on, QST issues that I received. I don’t do that every month nowadays, but I think it is a worthwhile exercise to do every two-three months. New products are always being introduced, and some of them can be quite useful and fun.

This month, I went through the ads in QST. Here are some that I highlighted.

  • Using Your Meter. This is a new book from The W5YI Group. It’s notable to me because I’ve been thinking that a simliar book might be my next publication. The No-Nonsense Guide to Using Your DMM—my working title—would be a lot cheaper than the $24.95 that W5YI is asking for this book, though.

    Got any tips for using a DMM? If so, e-mail me and I’ll include it in the book.

  • Bonito RadioJet 1102S. This is a software-defined receiver made in Germany and imported by a small company, Computer International, in Michigan. Unfortunately, the company’s website is a real disaster. I spent about ten minutes looking for a price for this radio without any luck.  So many small companies’ websites are so poor that I think it actually hurts, rather than helps their business.
  • MastrAnt. This company sells synthetic guy ropes. We’re going to need some of this down at the museum. I think the metal guy wires are detuning our 40m inverted Vee.

Do you peruse the ads in QST and other ham radio magazines? Which ones have you found interesting lately?

KB6NU finally builds an end-fed, half-wave antenna

I’ve posted about end-fed, half-wave antennas before, but until this weekend, I’d never built one. One of the reasons for this is that most designs are for QRP antennas and not made to handle more than 5 – 10 W of power.

A couple of months ago, I ran across a design rated at 100 W. The design seemed relatively simple to build, requiring only a single toroid and a capacitor made with a short length of RG-174 coax. Well, it just so happens that I bought 100-ft. of RG-174 at Dayton this year, and I found the toroid cores online from the  “Toroid King” for a very reasonable price, so I decided to make my own.

All told, the parts cost about $10, the biggest part of that the plastic junction box I got from Lowe’s for $6.41. Compare that with the $60 that LNR wants for their end-fed antenna.

Sunday was a beautiful day here with temperatures in the 60s, so I decided to put up the antenna. I’d love to report that everything worked perfectly, but this antenna is going to need a little more work. The SWR is 2.6:1 at 14.000 MHz, dropping to about 1.5:1 at 14.900 MHz.

Since the internal tuner on my IC-746PRO is supposed to be good to 3:1, I did use it and made a couple of contacts. The guy in MA even gave me a 599 signal report. I’d be a little more comfortable about using it, however, if I could get the SWR down a bit.

I e-mailed the guy who published the design and asked why he thought the resonant frequency was so high, and he said that all I had to do was add a couple feet of wire to the antenna. He also suggested that adding a turn or two to the coil would bring the SWR down. I did some more reading about end-feds and I’m thinking that perhaps adding a short counterpoise might be something to try, too.

So, while the results so far have been mixed, I’m hopeful that with a little tweaking, I’ll have another antenna to add to my arsenal. It’s been a good learning experience, and I’ve certainly saved a bunch of money over the commercial versions.

UPDATE 11/18/12:
I added 24-in. to the antenna  and it did indeed bring down the SWR of the antenna to below 2:1 in the CW portion of 20m.  I’m happier with this. I still do plan to try a counterpoise. Not so much to improve the SWR, but to see if it makes the antenna a little more efficient.

The box I used for this project is the Carlon E989NNJ, a 4-in. x 4-in. x 2-in. plastic junction box.  This is a very nice box. Not only is it completely enclosed. The screw down cover is gasketed, making it waterproof.

I liked the box so much, I went back to Lowe’s to get a couple more. Not only were they out of stock, when I searched their website for that part number, it came up with no results. It kind of looks to me as though they’re not planning to stack this box anymore.

I Googled the part number and found several places online that had them, but they wanted more money, plus I would have to pay shipping. Fortunately, I was able to find some at a local Home Depot. They wanted $6.88, compared to $6.41 at Lowe’s, but at least I was able to purchase a couple more of them.