USMC Antenna Handbook

If you’ve been looking for a practical, free introduction to antennas, the US Marine Core Antenna Handbook (MCRP 8-10B.11, 2016) is a good place to start. The book is especially good for simple HF antennas that can be put up at home or in the field.

USMC Antenna Handbook

The PDF is 193 pages. The main section of text is 160 pages, with a very good 20 page glossary at the back.

If you enjoy learning about antennas from this handbook, your next step should be the ARRL Antenna Book. If you’re not ready to shell out $65 for the 1024 page 24th edition of that book, check your local library. Older editions are less comprehensive, but they still have lots of great info. My 12th edition from 1970 is still useful. Antenna physics has not changed over time, just our understanding of it.

Let’s go over some of the sections of the USMC Antenna Handbook to see the strong and weak points.

Radio Waves, Propagation, and Noise

These sections are very good, especially about HF propagation. It could cover VHF/UHF multipath a bit better. Repeaters are not mentioned. Those are common in amateur radio, but apparently not in the Marine Corps. Serious VHF/UHF amateurs dig into other kinds of propagation not covered here, like tropospheric ducting, meteor scatter, moonbounce, aircraft scatter, and so on. Those are advanced topics, so it is reasonable to not cover them here.

Transmission Lines

This is not my favorite section, but the mistakes here are very common in popular explanations of transmission lines. Unbalanced vs balanced is not a helpful way to think of transmission lines. All kinds of transmission lines carry a mix of differential (balanced) currents and common-mode (unbalanced) currents. Also, it talks about baluns as balanced-to-unbalanced transformers, but they are most useful as common-mode chokes. Still, this is a fairly standard introduction to the subject.

HF Antenna Selection

Very good section, with lots of ideas for how to actually get wire into the air for horizontal dipole or vertical ground plane antennas. You won’t find coverage of ham favorites like the G5RV, off-center fed dipole, Carolina windom, or even the end-fed half-wave. The antennas covered here are all simple and proven.

This chapter does discuss NVIS (near vertical incidence skywave) propagation, something that is fairly recent in amateur practice. The first QST article on NVIS was in 1995 and it has only become popular in the last 10-15 years.

There is one interesting antenna that is new to me, the vertical half-rhombic. This requires a fair amount of space, up to 1000 feet, but is unidirectional and only needs one support.

VHF and UHF Antenna Selection

This section is a bit less useful because it relies on specific military antennas instead of describing types of antennas. For example, the OE-254 is a bow-tie vertical dipole, a low-Q, high-bandwidth antenna, but they just call it an OE-254.

Military VHF/UHF antennas need to work over a wide range of frequencies, but amateurs can use antennas optimized for the small number of bands that we are allowed to use. The most common single- and dual-band ham antennas are not described here, designs like collinear phased verticals, Yagi-Uda beams, haloes, Moxon beams, J-poles, and so on.

Field Repair and Expedients

Read this before ARRL Field Day! Here are some suggestions of what to do when an antenna insulator breaks.

Improvised insulators crop

Antenna Farms

Some really good advice on choosing antenna sites, useful even if you are just putting up one antenna. I don’t think I’ve seen this covered in detail in any other book. A lot of hams will end up with at least two antennas, one for HF and one for VHF/UHF, so this is a worthwhile read. We won’t normally be considering security measures like barbed wire and automatic weapons, so you can skip to the Technical Considerations section.

And that’s all! Enjoy learning about antennas.

Wheat Berry Surprise

I improvised a dinner with wheat berries and veg. Tina asked what I was making and I said “Wheat Berry Surprise”! This starts with Mark Bittman’s Cooking Grains, The Easy Way then I threw in more tasty stuff.

I used wheat berries (whole wheat kernels), but you can use any grain you prefer. Likewise, the greens could be chard, dandelion greens, turnip greens, etc. Most greens will cook more quickly than the lacinato kale. I tossed in some chickpeas for protein.

Wheat berry surprise

Ingredients

  • 1 cup wheat berries
  • 4 cups broth or water (I used chicken broth)
  • 2 tablespoons olive oil (approx.)
  • 1 medium onion, diced
  • 3 carrots, diced
  • 3 stalks celery, sliced thin
  • celery leaves, chopped
  • 1 bunch lacinato (dinosaur) kale, chard, or other greens, cut into ribbons
  • 1 can chickpeas, drained
  • 1 bay leaf
  • several sprigs fresh thyme
  • 1+ teaspoon salt (omit or reduce if using salted broth)
  • a few grinds of black pepper

Preparation

Put the wheat berries, thyme, bay leaf, and broth (or salted water) in a pot. Bring to a boil and simmer for 30-40 minutes or so. The wheat berries will be softened but chewy when done. See Bittman’s recipe for details.

While the grains are cooking, cut up the onions, carrots, and celery. The carrots should be diced small enough that they will cook while being sauteéd. I always add the leaves from the celery bunch because I like a bit of extra celery flavor.

Wash the greens. I find it easier to wash lacinato kale after it is cut. Strip the leaves from the stems, cut across the leaves, then put the ribbons in a salad spinner. Fill it with water, agitate the leaves, dump, do that again, then spin dry.

In a medium-sized pot (3 qts?), heat the olive oil, then sauteé the mirepoix (onions, carrots, celery ribs and leaves) until soft, about 10 minutes. Grind some pepper into the mix toward the end. Add some salt, if you want. If the wheat berries aren’t done, turn off the heat and cover.

When the wheat berries are done, remove the thyme twigs and bay leaf, then drain.

Turn the heat up on the pot with the mirepoix. Add the chickpeas and stir. Put about 1/4 cup of water in, then layer the kale on the onions and carrots, then dump the wheat berries on top of everything. Cover. The kale will cook with the steam from the water and the heat from the wheat berries on top.

After about 5 minutes, check the kale for doneness. It should still be a little chewy.

When the kale is cooked to your satisfaction, stir everything together and serve.

Technique

Stripping kale and chard off the stems with a knife is slow and fussy. Every time I did it, I thought that professionals must do it some other way, because this was taking way too much effort and time. Then I read about this fast technique in Samin Nosrat’s book Salt, Fat, Acid, Heat (see page 232).

You strip the stem out with your hands. Lay the leaf down on a cutting board, put two fingers astraddle the stem at the base of the leaf, then grab the bottom of the stem and pull up and out. The stem will come out and the leaves will be ripped off. Bits may stick to the stem or the stem might break, so tear off any remaining bits until you are satisfied. Stack the leaves at the back of the cutting board and they’ll be ready to chop.

Notes and Variations

Salt is a personal taste. Like beans, wheat berries can be tasty with a bit more salt. The broth I used has 530 mg of sodium per cup, which is about 1 teaspoon of table salt in 4 cups. To be precise, Pacific Foods Organic Free Range Chicken Broth has 2130 mg of sodium in 4 cups. Table salt has 2325 mg in 1 teaspoon. Diamond Crystal Kosher Salt, what I use, has 1120 mg of sodium in 1 teaspoon. So, take my recommendations with a grain of salt and trust your own taste buds.

Use vegetable stock to make this vegan.

Add pancetta (reduce or omit the salt). Get four ounces cut into small cubes (about 1/4 inch). Instead of olive oil, brown the pancetta slowly to render the fat. When it is done, remove with a slotted spoon and put in with the wheat berries. Continue with the recipe, sauteéing the mirepoix in the rendered fat. If there isn’t enough, add a little olive oil.

BaoFeng HTs and Spurious Emissons

The January edition of QST has some disturbing data about dirty transmitters in BaoFeng HTs.

Amateurs are responsible for their transmitters being clean, but most of us don’t have the test equipment to check that. Also, manufacturers must meet the FCC regulations for every transmitter sold.

The ARRL Lab set up at hamfests and tested the HTs that hams had with them. Over four years, only 5% to 9% of BaoFeng HTs passed the test. Alinco, Icom, Kenwood, and Yaesu had 100% pass rates. Wouxon improved from 83% to 100% over the years.

QST 2020 01 HT Testing

From “Technical Correspondence”, QST, January 2020, pages 60-62. This chart is on page 61. QST is available online to ARRL members. This is a link to the article online.

The FCC rules for spurious emissions are in 47 CFR § 97.307 – Emission standards.

What if you already own a BaoFeng, like me?

Run low power. This will reduce the amount of power in the spurious emissions. Reducing the power from 5 W to 0.5 W should reduce the spurious emissions by 10 dB. The spurs still won’t be 40 dB below the carrier, but they will be lower in terms of absolute power. It can’t hurt. It will make your battery last longer, too.

What if you want an inexpensive HT?

Instead of a $50 BaoFeng, save up a bit more for a $75 Yaesu FT-4XR. From my research, this is the only HT under $100 from a major radioo vendor.

The FT-4XR uses the same chipset as the BaoFeng, so it has roughly the same feature set. But it has a clean transmitter and better interference rejection in the receiver. It also has ham-specific firmware, like automatic repeater offsets. That should make it easier to use.

The FT-4XR also uses the same antenna connector as BaoFeng, so aftermarket Nagoya antennas might fit. I would probably try the Nagoya NA-771 for $17, which might fit. I’ve heard recommendations for the Diamond SRJ77CA ($27).

I linked to DX Engineering’s page above, but the FT-4XR is available at similar prices from Ham Radio Outlet, Gigaparts, and other ham stores. Amazon has it at a higher price ($83), oddly.

BaoFeng UV 5R Yaesu FT 4XE

How did this happen?

It appears that the BaoFeng radios were designed for the much more lenient Part 90 emission regulations and do not meet the amateur radio regulations.

An article by AD5GG compares BaoFeng UV-5R emissions to Part 90 (private land mobile) and Part 97 (amateur) regulations. The BaoFeng meets the weaker Part 90 limits, where spurious emissions are not to exceed -20 dBc (dBc is relative to carrier). Part 97 limits spurious emissions to -40 dBc, 100X lower than the Part 90 limit.

Designing for the Part 97 limits requires additional low-pass filtering on the output. The new parts may only be pennies, but it would require a new board design. Maybe new versions of the BaoFeng HTs will be designed to the stricter standards, but I’ll have to see proof of that. The UV-5R is up to the third generation, at least, and still not compliant.

How to get an Amateur Radio License

What are the steps for getting your first amateur radio license?

Start by taking an online test for the Technician license. It is easy and free. You will probably do better than you expect. After the test, note the areas that you need to study. hamexam.org is my favorite online test site. You only need a C (75% correct) to pass.

K6WRU license blur

Now that you know what to study, get a study buddy, get some study materials, or best, both. The No Nonsense Technician-Class License Study Guide by Dan Romanchik (KB6NU) is free as a PDF and is exactly what it says. Study the sections where you are having trouble and keep taking practice tests until you are happy with your scores. Download it from the KB6NU study guide page.

Take a break from your studying to find a license test session. That will give you a deadline. Use the ARRL license exam session search to find a session.

There might be a fee for the exam, up to $15. You can take tests for all of the license levels at one session, so go ahead and take the test for General. You might pass!

After that, find a mentor to help you get on the air. In amateur radio, we call these people an “Elmer”. Use the ARRL club search page to find one near you. On the Web, try the Amateur Radio Elmers Facebook group.

Choosing a radio? That is a different post.

Troop 4014’s First Hike

I learned a new park today, thanks to the girls in Troop 4014. We had a lovely hike at Edgewood Park in Redwood City. I’d never been there, but I’ll be back.

Trail in Edgewood Park

The Scouts chose the route, did all of the map reading and direction finding, and got us back to the trailhead without any fuss. I carried a map, but only looked at it once.

Finding the route

We saw lots of wildflowers, a darkling beetle (one inch long), and three western fence lizards.

Edgewood park western fence lizard

Here is our track. It was 2.14 miles with an elevation gain of 435 feet. It was a nature hike with lots of stops, so we weren’t trying to eat up the miles.

Edgewood Park GPS track

See you on the trail!

Getting Started with Troop 4014

Starting a troop from scratch is a completely different experience from stepping into a functioning troop as Scoutmaster.

Founder strip

We’ve had our third meeting in four weeks. We are using the First Aid track of the BSA meeting plans for new troops. At the first meeting, I showed the girls the initial meeting plans from the Hiking and First Aid tracks and asked them to choose.

Right now, meeting planning is more Den Leader style but breaking in to pairs for them to teach each other from the handbook or other materials.

At the second meeting I brought some parachute cord for knot tying. We cut it into lengths, then I set up a camp stove to fuse the ends, with a cup of water to cool them off. They spent over a half hour melting rope and getting it just right. Big fun.

4014 is not chartered yet. We have a commitment from the charter org and we are linked with Troop 14. We had four 11 year old girls on Tuesday. We have a line on one more, plus two 5th graders who are interested. They’ll “age in” at the end of the school year, but I’ll probably invite them as guests. We have a guest female ASM/mom from another troop and two moms who we can probably sign up.

The Scout rank is a lot harder than the old Scout badge used to be. It used to be a one-meeting badge.

I’m astonished that whipping the ends of a rope is required. I’ll have to go buy some laid rope and whipping twine. Didn’t climbers start using kernmantle rope in the 1960s? Wow.