Exhibit A: A standard-issue banana. We love it when a community grabs hold of an...

Let’s start with a story about how NOT to strip wires. Back in the day, I worked with a fellow who had the unique talent of stripping wires with his teeth!

Well, just two of his teeth, actually.

It seems that at some point in his youth, he chipped the adjacent corners of his two front teeth just a little bit. The size of that little gap was just right for hookup wire, telephone wire, and all sorts of other wires. He would put the wire between his teeth, bite down just a little, and pull. Voila! Wire stripped and insulation spit out.

DON’T TRY THIS AT HOME!

Lucky for us, there are many great and inexpensive tools for getting insulation off of wires. You might only need to do that occasionally or you might need to strip dozens of wire ends. Whatever your need, there is a tool for you.

Let’s start with the most common and inexpensive manual stripper.

Basic Wire Strippers

My first order of business is to warn you about the too-cheap, no-name combo tools. While it might be nice to have one of those in the glove compartment for emergencies, they really aren’t quality workbench and toolbox tools. Good tools will last and last while doing the job right, so spend the extra few bucks on a “real” wire stripper from a solid tool company. If you need to spend a few bucks to qualify for free shipping, you could do a lot worse than to buy a good spare stripper.

Below is the Klein 1010, a basic wire stripper from Klein Tools, a well-known and trusted name in the electrical industry. As you can see, it not only strips and cuts wires from 10-22 AWG but crimps terminals, cuts small screws, bends wire, and has small plier jaws.

All of these functions are demonstrated in this handy video, “8 Wire Stripper Features Everyone Should Know.”

This is a low-maintenance tool. Keep it clean and free of rust and it will be your toolbox buddy forever.

Once I discovered it, I’ve used the small-screw cutter many times, making a short screw that was just right for the job. The important thing is to insert the screw so that after it’s been cut, you use the threaded part of the cutter to clean and re-align any distorted threads as you removed the screw. And sometimes, the little studs that are left can be used to join nuts or spacers.

You can tell I never throw anything away!

If you do a lot of home AC wiring, you can also find heavier strippers designed for the Romex-style cable and wire sizes you’ll encounter in those jobs. These will do a better job than the small strippers for electronic and radio work. They are also a little easier on your hands for the harder squeezing and pulling necessary for that type of work.

The pocket-friendly Squirt ES4 is a nice variation in the Leatherman line of multi-tools. Widely available used and occasionally new or in similar models, it includes a dandy little combination of wire stripper/cutter/needle-nosed pliers.

Folded up, the tool is less than two inches long. You’ll forget you’re carrying it, which is a bad thing if you try to take it through airport security! I’ve had to give up a couple of these that way, which is probably why they’re available used! Larger Leatherman multi-tools are also available with wire strippers.

Using manual strippers is pretty straightforward: insert the wire into the appropriate hole, squeeze, and pull. But there are a few fine points:

• Be sure to use the right size hole, otherwise you’ll nick solid wire (leading it to break when bent) or cut off strands of stranded wire.
• Using a too-large hole means you’ll get a ragged edge on the insulation and often pull the wire out of a multi-conductor cable.
• Don’t rock the stripper back and forth because that will nick the wire. If you have to do this to get the insulation off, either you’ve used the wrong hole or the jaws are dull and the tool should be replaced.
• Pull the wire straight through the stripper and don’t bend it, causing nicks and cutting strands.
• If you find the stripping force pulling one wire out of a multi-conductor cable, use needle-nosed pliers to hold the wire while it’s being stripped.

Using a diagonal wire cutter as a stripper is a skill many of us old-timers have developed. Like my friend with the chipped teeth, there is a knack to doing it without damaging the wire. A gentle squeeze will put a nick in the insulation which will then break and slide off the wire. This will only work reliably on insulation that breaks cleanly and won’t leave a clean edge on the insulation. 

Automatic Strippers

Sometimes you’ll find yourself faced with having to strip many wires for a big wiring job or preparing multi-conductor cable for a rotator or control circuit.  If you are installing crimp terminals or connector pins, you need to strip all of the wires consistently and with the right length of exposed wire. This is where a self-adjusting wire stripper comes in very handy.

Properly set, these strippers will make a consistent, clean strip over and over. That results in higher quality work with better reliability.

Another item in the Klein Tools catalog, the Klein 11061 is a typical example of these tools. They don’t have all of the accessory features of the 1010 but make short and consistent (there’s that word again) work of stripping a lot of wires. After you insert the wire between the jaws, squeeze the handles—the jaws clamp the wire, and the blades come together to cut and pull off the insulation.

Here’s a video of how to use it and how they work

The Performance Tool W200 is a variation of the automatic strippers. It has jaws to hold the wire and a pair of cutting blades that come together and pull off the insulation. The sequence is completely automatic and the design of these tools to make this sequence happen is pretty nifty.

Pistol-grip adjustable automatic strippers are also available, such as the Tool Aid 19100. The wire is inserted in the end of the jaws until it contacts the adjustable stop. Squeeze the jaws and the tool does the rest. This tool is intended for smaller gauge wire from 12 to 22 AWG.

I’ve used all of the different types of strippers and each has their appropriate role. I carry a manual and an automatic stripper in my tool kit. These are also fairly inexpensive and worth adding to your tool roster. You might also enjoy Adam Savage demonstrating how these work in this entertaining video.

Stripping Enameled Wire

So far, we’ve focused on wire with plastic insulation, and that is most of the jobs you’ll encounter. However, if you wind toroids or impedance transformers or baluns, it’s common to use enameled wire which is harder to strip. You want to avoid nicking the wire with a cutter or knife—it will break from mechanical or thermal flexing—so a different technique is required.

A convenient method for occasional use is to use sandpaper or emery boards. A small strip of sandpaper held between your fingers to squeeze the wire is an easy skill to learn. Squeeze the wire, rotate it, and pull it in and out of the sandpaper. This scrapes off the enamel without damaging the wire underneath.

This video shows how to do it properly.

If you have a big project with a lot of inductors or transformers, you can save yourself a lot of work (and sore hands) by using a power tool to scrape off the enamel. The Abisofix tool shown in the photo and this video will do the job on a wide range of wire sizes from 12 to 24 AWG. For very fine wires, the manual method is best for the home builder.

Removing Heavy Insulation

A situation you’ll encounter frequently is removing the outer insulation from multi-conductor cables like rotator control or networking cable. If you don’t have a special cable stripper, you’ll have to use a knife or razor blade to remove the insulation. Be sure to use a SHARP, new blade for a utility or craft knife. A dull blade will make this job hard to do well.

1. Score the insulation—cut the insulation but not all the way through. You can hold the cable in one hand and cut with the other, but an easier and more controlled way is to place the cable on a work surface and roll it under the blade.
2. Do not cut into any of the inner conductors. It’s best to cut too shallowly at first, then go deeper as needed.
3. Bend the insulation back and forth so that it breaks along the score. You may need to touch up the scoring in spots.
4. Twist the insulation off in the same direction that the individual strands twist.

If you are working with coaxial cable, use a stripping tool for coax if possible. Those tools are well-covered in other On All Bands articles and videos.

However, sometimes you have to strip coax manually. First, when removing the outer insulation, be extra careful not to cut through the fine strands of shield braid. Take your time and work through the outer insulation. Use your sharpest wire cutters when removing the braid. Then repeat the score-and-bend technique to loosen the center insulation. 

It’s often hard to pull off coax’s solid center insulation without pulling it partially out of the braid. You can use manual wire strippers to hold the remaining insulation while pulling off the unwanted part. Carefully close the strippers on the center conductor using a stripper hole one or two wire sizes larger than the conductor so it doesn’t nick the coax conductor. Then slowly pull off the center insulation, remembering to twist the insulation in the same direction as the strands of wire.

Use the Right Tool

Just to repeat the message, use the right tool for the job and learn how to use it properly. So many problems in the ham station trace back to connectors and wires breaking or pulling loose. By doing it right the first time, you can save yourself a lot of headaches and keep ham radio fun. No matter what the type of wire or cable, there has probably been a special tool designed for it.

Many are quite inexpensive—don’t you have a birthday coming up?

The post How To Strip (Wires and Cables) appeared first on OnAllBands.

One of the great things about ham radio is the amazing variety of items that can be purchased to add more enjoyment to the world’s best hobby. Case in point: Today’s featured video on some of the latest products available at DXEngineering.com.

DX Engineering’s Michael Murphy, KI8R, highlights a few excellent station add-ons in his series, “What’s New at DXE,” including products from Chameleon Antennas, Eclipse Tools, RigExpert, Nifty Reference Guides, InnovAntennas, Comet Antennas, RT Systems Radio Programming Software, and DX Engineering.

Watch the video and find many more details on these featured products by clicking on the links below:

Chameleon Antenna URT1 Universal Remote Antenna Tuner

InnovAntennas LFA-WOS 6M 7-Element Yagi

Shackmaster Power 600 Compact Desktop Power Supply

Eclipse Tools Butane Gas Soldering Iron Kit

Eclipse Tools PK-616A Professional Electronics Tool Kit

Eclipse Tools SS-969E SMD Hot Air Rework Station

Eclipse Tools 3-5/16 True-RMS Compact Digital Multimeter

Eclipse Tools SS-628A Mini Hot Air Gun

2024 Contest University Textbook

Nifty Mini-Manual for the Kenwood TH-D75A Tri-Band Handheld

RTS Programming Software and Cable Combos for the Kenwood TH-D75A and Icom ID-50 Handheld Transceivers

Comet Mobile Antenna Mount Adapters

• AD-10N: NMO to Type-N Female (below)
• AD-15M: NMO to SO-239 Female
• AD-25M: SO-239 Female to NMO
• AD-35M: 3/8-24 Threaded Receptacle to PL-259

The post New Products Spotlight Video: Chameleon Remote Antenna Tuner, RigExpert Power Supply, and More appeared first on OnAllBands.

We’ve all got our favorite hand tools, and while the selection criteria are usually pretty...

As we’ve discussed at length at OnAllBands, effective soldering can be tricky, especially if you don’t have the right tools. DX Engineering understands the importance of equipping your shack with proven equipment that makes even the most delicate jobs a lot easier.

That’s why you can find a range of reliable soldering tools and accessories from leading brands (Eclipse, ECG, Kester, Milwaukee Tool, American Beauty) at the tools & supplies section of DXEngineering.com. Choose from high-quality solder wire, flux, rechargeable and wireless soldering irons, temperature-controlled soldering stations, desoldering stations and pumps, soldering tools for printed circuit boards, soldering tip cleaners, magnified alligator-clip work holders, and more.

If you’re a novice when it comes to using a soldering pen or need to brush up on your technique, read this article from Mark, K8MSH, “Ham Radio 101: Soldering Tips.” It’s also a good reminder to treat these tools with a great deal of respect by taking all necessary safety precautions to avoid injury when soldering.

Finished the article? Great! Now check out the latest Eclipse Tools soldering products available at DXEngineering.com:

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Economy Dual Temperature Soldering Station

This unit features a selectable 20- or 40-watt temperature setting, making it easier to switch from general electronic soldering and repair to cable terminations or hobby and craft projects. The station is ideal for both professional and do-it-yourself projects and comes equipped with a pencil tip-style soldering iron, built-in stand, and tip cleaning sponge. Find many more soldering guns and irons at DXEngineering.com.

***

Helping Hands Work Holder

This heavily weighted mini work stand features a universal joint for positioning your work, along with an arm and two strong alligator clamps to hold parts in place or wires for soldering. For tiny projects, the work stand includes a magnifier that will make minuscule parts look big. A great choice for amateur radio repair, RC hobbies, model railroading, crafting projects, and many other purposes.

***

SI-BI62 Battery-Operated Soldering Iron

Featuring a compact, cordless design for optimum portability, the seven-inch-long SI-BI62 boasts a rapid heat-up time of only 15-20 seconds, ensuring that it’s ready to use at a moment’s notice. The safety cap automatically powers down the device when it’s attached. Power consumption is only 8W, with a maximum temperature of up to 842° F. It maintains a soldering temperature of at least 600° F. Requires three 1.5V alkaline AA batteries (not included).

***

SI-186A Digitally Controlled Soldering Iron

Designed for precision soldering tasks, the SI-186A features digital temperature control for accurate heat management. It’s equipped with a ceramic heater that ensures rapid heating and recovery, boasting a power consumption of only 60W and temperatures ranging between 392° to 932° F. Other features include temperature correction and a smart memory that automatically remembers the last used temperature. The SI-186A comes with a replaceable long-life tip, soft grip handle, and LED display.

***

Soldering Iron Tip Cleaner

This coiled-wire type cleaner doesn’t burn and won’t allow solder to stick. Since the soldering iron tip cleaner is used dry, it won’t cool your iron when you clean the tip. All it takes to provide a clean tip for smoother solder flow is a quick wipe of your iron through the steel-wool style cleaning ball.

***

SS-969E SMD Hot Air Rework Station

This versatile station is useful for rework and soldering operations on a broad range of components, as well as for heat shrinking, drying, paint removal, pre-heating, glue soldering, and more. The SS-969E offers adjustable settings for airflow, air volume, and temperature, providing users with a high degree of control. At 700W, it delivers a wide temperature range of 212° to 842° F and features an auto cool-off process to extend the life of the heating element. Safely solder QFP, PLCC, BGA, and other temperature-sensitive components with ease.

***

Fine-Tipped Flux Bottles

Sold in packs of two, Eclipse Tools fine-tipped flux bottles evenly dispense flux. A gentle squeeze of the bottle allows the fine-tipped needle to deposit flux exactly where you need it for a precision application.

***

Desktop Inspection Lamp

This 700 lumen, LED magnifier table lamp features 2.25X(5D) magnification, a scratch-resistant glass lens, low-temperature LEDs, standard desktop clamp mount that fits surfaces up to 2.56 inches thick, and adjustable arm for easy positioning. Find other Eclipse Tools desk inspection lamps at DXEngineering.com.

***

Visit DXEngineering.com for the complete lineup of soldering products from Eclipse Tools plus a great selection of useful shack additions: heat shrink tubing, multimeters, volt testers, heat guns, wrap ties, and more.

The post New Product Spotlight: Soldering Tools and Accessories from Eclipse Tools appeared first on OnAllBands.

Title: Elevate Your Amateur Radio Experience with Station Master Software: A Comprehensive Guide “Amateur Radio Station Master Software: Elevate Your Radio Experience, Connect with Confidence.” Introduction:Amateur radio enthusiasts understand the importance of seamless communication and efficient station management. In the world of ham radio, Station Master Software has emerged as a powerful tool, providing operators […]

I'll describe a simple 8, or 4 Ω dummy load to test your home brew guitar power amplifiers.

Low cost 16 Ω / 25W wire wound, aluminum shell, chassis mount resistors seem abundant.  I got mine on eBay.  Wire wound resistors vary in quality, design and tolerance. Some even exhibit low inductance by winding with an Ayrton-Perry bifilar technique.  Resistor tolerances range from 10% down to ± 0.5 % + 0.05 Ω.  Typical manufacturer power ratings are done at 25C, however, these devices are meant to sit on a heat sink when used and that's why the aluminum housing contains 2 relatively large mounting holes.

I crafted my heat sink from MG Chemicals Copper Clad Board, Double Sided, 1 oz Copper, 1/16" thick, FR4.  My entire chassis serves as the heat sink. I come from an RF background and we builders use double sided board for enclosures, heat sinks, shields, and of course, for our circuit boards.  I employed a clumsy 80W soldering iron to solder my boards together.


Above — Project schematic. My switch rating = 6A at 225 VAC. I opted to use a standard 1/4 inch speaker jack as the input. I connect it to my power amps under test via a short home brew patch cable.


Above — Front view of my dummy load. 


Above —Side view.  Each power resistor's ground wire passes through a hole drilled in a double sided Cu clad "vertical fin" board. The tip of each ground wire was bent flush against the copper fin board and soldered. The copper fin board is soldered to the main board on both sides providing a low impedance ground, plus some heat sinking.  You can't well see it but I completely soldered the  grounded resistor side of the copper fin board to the main board.

The input side of the power resistors connects to the input jack and switch via bare, solid core 22 gauge wire that's folded in half, twisted and then soldered together.


Above —Above, oblique view.  You can see the vertical, ground wire "fin" copper board and a secondary vertical fin Cu board behind it for added heat sinking.


Above — I applied thermal grease to the bottom of each aluminum power resistor enclosure before bolting them down.  I've enjoyed good results with MG Chemicals' super thermal grease II in many previous projects. Wear gloves and lay out some paper to prevent a messy bench + greasy hands.

Above —Bottom of main Cu board. The 2-sided board provides reasonable heat sinking, plus mechanical strength.  The nuts and bolts connect the top and bottom board sides at DC & @ AC out to High Frequency.  I placed 4 stick-on rubber feet for a sturdy base.


Above — The holes in my green power resistor aluminum enclosures were big enough (3.5mm/0.14inch) to allow the use of 6-32 hardware — you can really bolt them down securely to your heat sink. 


Above — Close up photos of my particular power resistors.  I purchased them for $2.59 CAD each including shipping and handling. Quite reasonable.

RF Assessment

With a strong RF background, the term 'wire wound resistor' strikes a bit of fear in my heart. I measured my resistor's inductance, plus swept 1 in a tracking generator + spectrum analyzer from ~ 9Khz to 1.3 GHz.

Typical inductance of the couple of resistors I tested from my batch= 889 nanoHenries. My sweep revealed that the series resonant frequency (SRF) of 1 of my batch of resistors = ~ 109 MHz.  The notch @ ~ 109 MHz isn't very deep; it's around 14 dB down from reference.

This fits with my lab experiences.  I keep a good selection of wire wound chip inductors for building circuits in the 100 - 1200 MHz region.  Every chip inductor I own has been swept and characterized — I keep a high Q,  Coilcraft, wire wound, 880nH, size 0603, SMT inductor and its SRF = 104 MHz.  In truth, a chip inductor & a power resistor compare poorly, but give the chip inductor gives a ballpark SRF reference of what to expect.

Of course, the SRF notch of my high Q SMT part is ~44 dB deeper than a lousy 16 Ω power resistor.  Since the power resistor is low in resistance (and will go in parallel with other 16 Ω resistors), its a low Q inductor — and with a SRF above 100 MHz, it will work fine as an AF power resistor.

Resistance and Temperature


Above — My 16 Ω resistors tolerance = 5%.  With all 4 resistors in parallel I measured 4.28 Ω at room temperature with my DVM in high resolution mode. With the resistors at 48.9 degrees Celsius, my DVM measured 4.29 Ω,  I will use 4.28 Ω as my "4 ohm" resistor value in all amplifier power calculations based on bench measures.



 Above — With 2 resistors in parallel I measured 8.29 Ω and this rose to 8.3 Ω when the resistor's temperature rose to 50.6 Celsius.  Resistor temperature coefficient =100 PPM / C .  I'll use 8.29 Ω as my resistance when calculating power from measures made on the bench.


Above — An infrared temperature monitor proves invaluable for bench temperature measures. I measure the temp of my power resistors — and also project AF and RF final transistors temperature with this device.

I put my switch in the 8 Ω setting and ran a 1KHz signal generator into a small power amp with the dummy load connected. I set a measured 15W output power and let it run for 15 minutes unattended to heat up my dummy load.  After 15 minutes, the peak temperature on the 2 power resistors in parallel = 50.6 C.  This seemed @ steady state, as the temperature did not rise above 50.6 C.

Then I switched to the 4 Ω setting, drove the load for 15 W measured power and let it run for another 10 minutes or so . The peak temperature measuring on top of the resistors was 46.5 C.  Distributed across the 4 resistors, my dummy load ran cooler than with the same output power into 8.29 Ω paralleled pair.  All as expected.

During normal bench measurements of power, or when setting the bias on a tube amp; or adjusting the trimmer potentiometer to set DC voltage for the VBE multiplier on a solid state PA, it probably only takes < 5 minutes.  Thus a continuous 1 KHz wave @15W for 15 - 25 minutes proved a bit of a torture test.

In 2019, I hope to build some guitar amps that exhibit a clean average peak power of 40W or so. I'll carefully measure my dummy load & update this posting when I've got some more temperature data.  Clearly, if you want to torture test a load driven to 100W measured power, you'll have to consider increasing the heat sink area, apply more resistors, or perhaps, spawn a correct thermal resistance heat sink design using math and measures. 

Mine is just a hack — and it operates within spec for my particular resistors and needs.


Above — the temperature of my concrete floor.  It's already cold in my lab and we're barely into the Canadian winter. That's ~60 F for those who dwell in the USA.


Above — My previous home brew 8 Ω dummy load made sometime in the 1990s.  The big resistors are 2W rated 1% tolerance resistors and this worked OK for the AF power amps I built up until the last couple of years.

Power Calculation

It seem that some people quote a guitar amplifier's peak versus RMS power etc.  This causes confusion.


For reference, here is how I calculate the maximum power for all the guitar amps I'll present over time.  To measure power, we employ a signal generator ( often a 1 KHz sine wave, low distortion signal source ); an amplifier under test that contains a power amp stage; and finally a purely resistive load such as the dummy load I presented.

Above — Average power formula.  We advance the signal generator gain until distortion appears on the oscilloscope output. Then we back it off slightly to re-establish an output free of distortion by viewing the sine wave on an oscilloscope; or the sine wave and/or FFT in a digital storage oscilloscope.

The oscilloscope peak to peak voltage gets divided by 2 to give the peak voltage.

The peak voltage is then squared.  The peak voltage squared is then divided by 2X the load resistance. So if the dummy load is set to 8 Ω, we would divide by (2 times 8) which is 16 Ω.

For my particular dummy load, I'll use (2X 4.28 Ω) or (2X 8.29 Ω) for my load resistance.

Click for my Guitar Related Index