Amateur radio tip of the day: Low SWR isn’t the “be all and end all” it’s sometimes made out to be

Ham Radio Tip of the Day
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Today’s tip is from Bob, KG6AF. For submitting this tip, Bob will get one of my e-books. Thanks, Bob!

Low SWR isn’t the “be all and end all” it’s sometimes made out to be. Just because you measure a low SWR, it doesn’t mean that your antenna is radiating efficiently. Conversely, a high SWR doesn’t mean that an antenna won’t radiate. Remember that a 50-ohm dummy load has a 1:1 SWR.

Most modern rigs will reduce or cut off transmit power if the SWR the transmitter sees is higher than 2:1, so you do have to make sure that the impedance the transmitter sees at the antenna connector is close to 50 ohms. To do that, we often use an antenna tuner. An antenna tuner will make the transmitter happy, but that doesn’t mean that the transmitter’s output power is being radiated by the antenna. There are many other factors that come into play.

Take the time to read reliable material on the subject. The ARRL Guide to Antenna Tuners, by Joel Hallas, W1ZR, is a good starting place. You can also find lots of solid information in the QST archives.

73!

Dan KB6NU

THIS WEEK’S WINNER!
Every week, I select one of this list’s subscribers to get one of my e-books. This week’s winner is Jared, N7SMI.

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Tips like this one are sent out every day by e-mail. To subscribe to the list, simply click here and fill out the form. Every week, I’ll select a random subscriber and give them one of my books.

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Amateur Radio Tip of the Day: Choosing your first radio

Choosing a Ham Radio by the ARRL is a well-written guide designed to help the newcomer choose his or her first radio. It will help you decide which features are the most importan for the type of operating that you plan to do, and the best part is that it’s FREE!

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Do  you have a tip that you’d like to share with other radio amateurs? E-mail it to me. If I use your tip, I’ll send you one of my books.

Amateur Radio Tip of the Day: Keep your soldering iron tip clean

To make good solder joints, you need to keep the tip of your soldering iron clean from any oxides and dust or dirt. A clean, well-tinned tip will transfer heat properly and help you avoid cold solder joints. Many solderers use wet sponges to clean soldering iron tips, and many solder stations have troughs to hold these sponges.

soldering_iron_tip_cleaner

An alternate method is to use a wire cleaning pad like the one shown above. You stick the iron into the pad and then draw it back out. The wire scrapes the oxides and dirt from the tip as you do this. Proponents of this method claim that this method increases the life of the tip as it avoids the rapid temperature changes that using a wet sponge cause.

73!

Dan

OUR FIRST WINNER!
Larry, KB8QJE, is this week’s winner of one of my e-books. His name was randomly selected from the subscriber list.

SUBSCRIBE
Tips like this one are sent out every day by e-mail. To subscribe to the list, simply click here and fill out the form. Every week, I’ll select a random subscriber and give them one of my books.

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Do  you have a tip that you’d like to share with other radio amateurs? E-mail it to me. If I use your tip, I’ll send you one of my books.

Tip of the Day: Add elements to make a single-band dipole a multi-band antenna

You can make a make a simple dipole antenna into a multi-band antenna by adding an additional set of elements for the band you want to operate. A couple of years ago, I added 30m elements to my 40m dipole and now it works on both 40m and 30m. The reason this works is that when operating 40m, the 30m elements present a relatively high impedance, while the 40m elements a relatively low impedance. RF current, like any kind of electrical current will take the path of least resistance.

As shown below, the 30m elements hang down below the 40m elements. If you space the elements close to one another, you may have to tweak the lengths of the elements for the best SWR. In my case, that wasn’t a problem.

fan-dipole

If two bands is good, why not four or five? Yes, you can do that. You can add as many bands as you have space and wire for.

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Tips like this one are sent out every day by e-mail. To subscribe to the list, simply click here and fill out the form. Every week, I’ll select a random subscriber and give them one of my books.

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Do  you have a tip that you’d like to share with other radio amateurs? E-mail it to me. If I use your tip, I’ll send you one of my books.

Tip of the Day: Collect tech books from the 1970s

1974-arrl-handbookTodays tip is from Kenneth Finnegan. Thanks, Kenneth!

Collect as much technical literature from the 1970s as possible, including ARRL Handbooks, magazines, etc. This was the decade when transistors and basic ICs were affordable, but monolithic ASICs for every problem didn’t exist yet. I’ve found literature from this era to be the most educational for discrete electronics design and understanding how contemporary one-chip-solutions work.

Tip of the Day: Is that deal too good to be true?

If a deal at a hamfest seems too good to be true, it probably is. A couple of years ago at the Dayton Hamvention, I found a Vibroplex bug for only $50. When I got it home, I discovered that the silver-plated contacts had been filed, making it practically useless. Fortunately, I was able to purchase new contacts, but that cost me $40, making the deal not nearly as good as it first appeared.

Make sure you take a good, hard look at whatever it is that you’re going to buy before handing over the cash. If it’s a radio or a power supply, ask the seller if you can at the very least plug it in and see if it powers up. And, if you’re unsure, ask a friend who might know more to take a look at it before you buy something.

 

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Tips like this one are sent out every day by e-mail. To subscribe to the list, simply click here and fill out the form. Every week, I’ll select a random subscriber and give them one of my books.

GOT A TIP?
Do  you have a tip that you’d like to share with other radio amateurs? E-mail it to me. If I use your tip, I’ll send you one of my books.