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Today — 5 October 2024Ham Radio Blogs

Fall “POTA” Event

By: VA3QV
4 October 2024 at 15:32

Support Your Parks

This event happens seasonally, on the 3rd full weekend of the month (Saturday & Sunday UTC). These are ‘activity weekends’ where the main purpose is to get out in the parks, and have as much fun as possible.

  • Winter – 3rd Full Weekend of January. January 18-19, 2025
  • Spring – 3rd Full Weekend of April. April 19-20, 2025
  • Summer – 3rd Full Weekend of July. July 19-20, 2025
  • Autumn – 3rd Full Weekend of October. October 19-20, 2024

Hope to get you in my Logs during the upcoming event….

73bob

Yesterday — 4 October 2024Ham Radio Blogs

Fall “POTA” Event

By: VA3QV
4 October 2024 at 15:32

Support Your Parks

This event happens seasonally, on the 3rd full weekend of the month (Saturday & Sunday UTC). These are ‘activity weekends’ where the main purpose is to get out in the parks, and have as much fun as possible.

  • Winter – 3rd Full Weekend of January. January 18-19, 2025
  • Spring – 3rd Full Weekend of April. April 19-20, 2025
  • Summer – 3rd Full Weekend of July. July 19-20, 2025
  • Autumn – 3rd Full Weekend of October. October 19-20, 2024

Hope to get you in my Logs during the upcoming event….

73bob

Before yesterdayHam Radio Blogs

Back home a week later

By: VA3QV
30 September 2024 at 16:50

It was a great time being back in Ottawa, visiting with friends from my old neighborhood and also spoiling my Daughters two cats.

However on the “Radio side” of things …. not so good

The plans were that I would be able (weather permitting) continue to control my hour on the Trans Provincial Net while away. It seemed that “Mother Nature” had different ideas. Most days rain or the threat of rain kept me from heading over to the park.

Above pic showing where the park was and the route I took

As I mentioned in a previous post…. there was a local (non-POTA) park within walking distance to operate from. It was a local sports field and had some bleachers for when the crowds came for Junior Soccer/Football and or Rugby…

Below pic showing how I set up at the park

Although the operating position was excellent there was NO PROTECTION from the elements which in my case meant rain.

I was able to wrap my MFJ mast to one of the bleachers and stretch the end of the EFHW antenna to the other bleacher and it did work like a charm. Signal reports were great considering I was running 50w into the antenna

So for 1 out of a potential 5 operating days it was fun and dry. Walking home with the gear safely packed in the backpack “Mother Nature” paid a short visit.

I also managed to activate CA1515 and CA1516 using my Xiegu X5105 along with a 29 foot wire (supported by the same mast mentioned earlier) with a 9:1 unun, a 17 foot counterpoise with a choke on the radio end of the coax. Jose VA3PCJ was nice enough to offer me a ride there and back. I activated the parks using SSB and VA3PCJ activated the same parks using CW and his KX3.

For Jose’s version of the park activation click HERE

I am expecting to be returning to Ottawa in Mid-January 2025 for another visit with my GrandKits and like last years winter visit there will be a car to keep me warm and dry.

73bob

Back home a week later

By: VA3QV
30 September 2024 at 16:50

It was a great time being back in Ottawa, visiting with friends from my old neighborhood and also spoiling my Daughters two cats.

However on the “Radio side” of things …. not so good

The plans were that I would be able (weather permitting) continue to control my hour on the Trans Provincial Net while away. It seemed that “Mother Nature” had different ideas. Most days rain or the threat of rain kept me from heading over to the park.

Above pic showing where the park was and the route I took

As I mentioned in a previous post…. there was a local (non-POTA) park within walking distance to operate from. It was a local sports field and had some bleachers for when the crowds came for Junior Soccer/Football and or Rugby…

Below pic showing how I set up at the park

Although the operating position was excellent there was NO PROTECTION from the elements which in my case meant rain.

I was able to wrap my MFJ mast to one of the bleachers and stretch the end of the EFHW antenna to the other bleacher and it did work like a charm. Signal reports were great considering I was running 50w into the antenna

So for 1 out of a potential 5 operating days it was fun and dry. Walking home with the gear safely packed in the backpack “Mother Nature” paid a short visit.

I also managed to activate CA1515 and CA1516 using my Xiegu X5105 along with a 29 foot wire (supported by the same mast mentioned earlier) with a 9:1 unun, a 17 foot counterpoise with a choke on the radio end of the coax. Jose VA3PCJ was nice enough to offer me a ride there and back. I activated the parks using SSB and VA3PCJ activated the same parks using CW and his KX3.

For Jose’s version of the park activation click HERE

I am expecting to be returning to Ottawa in Mid-January 2025 for another visit with my GrandKits and like last years winter visit there will be a car to keep me warm and dry.

73bob

POTA with the (tr)uSDX

By: WB3GCK
28 September 2024 at 22:52

Although I bought my little (tr)uSDX transceiver two years ago, it has only seen sporadic use. Other than an occasional contact or two, it has been mostly relegated to the shelf. I figured it was about time to put it to serious use in a POTA/WWFF activation. 

I made a return visit to Norristown Farm Park (US-4363, KFF-4363) for another activation. It was raining on and off this morning here in southeastern Pennsylvania, so I pretty much had the place to myself. 

I set up the (tr)uSDX with my Elecraft T1 tuner in the cab of my truck. I used three 18650 Li-ion batteries power the radio. As usual, I went with my 12-foot whip and homebrew loading coil on the back of the truck.

I’m getting a little better at navigating the (tr)uSDX’s menus and using the controls. There are a lot of functions covered by three controls. To refresh my memory, I used the rig last night with my rain gutter “antenna” to make a couple of contacts. I also brought along a cheat sheet today, which I didn’t need.

Just for the fun of it, I started off using my little N6ARA TinyPaddles. They match the orange radio, so why not. Unfortunately, I had some issues with them, so I switched over to my Palm Mini paddles. I have to tweak the contact spacing on the N6ARA paddles. 

My (tr)uSDX. The N6ARA paddles are in the lower left.
My (tr)uSDX. The N6ARA TinyPaddles are in the lower left.

Starting out on 40M, the signals were strong and plentiful. It only took me about 11 minutes to log my first 10 contacts. When things slowed down on 40M, I made a few contacts each on 30M and 20M. After 45 minutes, I had 21 contacts in the log with one park-to-park QSO.

My trusty homebrew loading coil. In hind sight I should have used a plastic bag to protect it from the rain this morning.
My trusty homebrew loading coil. In hindsight I should have used a plastic bag to protect it from the rain this morning.

The (tr)uSDX is an incredible little rig. They packed an awful lot of features into a tiny package, but it’s not really a high-performance radio. I have to admit it wasn’t the most pleasant rig to listen to; there were some pops and clicks in the sidetone when keying. It could have been the earbuds I was using. I also need to go back through the menu settings to make sure I haven’t missed something. Looking at my RBN spots, I could see I need to tweak the frequency calibration a bit. It’s transmitting a little lower than the displayed frequency. Having said all that, I can’t be too critical of radio at this price point.

In the end, though, the little rig got the job done today. Not bad for a five-band, multi-mode radio that costs less than $140 assembled. 

72, Craig WB3GCK

The Mystery of the Sticky Feet

By: WB3GCK
26 September 2024 at 23:19

I’ve been powering up some of my old QRP gear to see if any of it still works. The gear has been stacked up on a shelf above my operating position for years. In testing some of this gear, I came across a curious problem.

Last night I was rearranging some of my equipment and re-routing some coax cables. When I went to move my Oak Hills Research power meter, it was stuck to the shelf. The rubber feet on the bottom of the meter had become slightly soft and sticky. I didn’t think too much of it at the time. I just finished connecting the cables and placed it back on the shelf. 

Today, I took my old MFJ-9030 transceiver down from the shelf and was greeted with a gooey mess. The rubber feet had completely dissolved and turned into a sticky, tar-like mess. Using a single-edged razor blade, I scraped off as much as I could from both the radio and the residue on the shelf. I used some mineral spirits to clean up as best I could. The mineral spirits worked great, but I still had sticky spots where the feet were attached to the radio. I cut some pieces of aluminum duct tape to cover those spots, and I applied four new feet from my junk box. 

This is the underside of my 31 year old MFJ-9030 transceiver showing the black goo from the dissolved feet. The clear feet were added by me.
This is the underside of my 31 year old MFJ-9030 transceiver showing the black goo from the dissolved feet. The clear feet were added by me.

My theory is that the rubber (or whatever material they are) feet reacted with the finish on the shelf. I know that vinyl guitar straps and accessories can damage the lacquer finish used on some high-end guitars (like my 1973 Martin D35 acoustic), so I suspect something like that happened to my radio equipment. I built the shelf and my operating table from some repurposed shelves that were in the house when we moved in back in the late 70s. So, I have no idea what kind of finish is on them. 

Besides the power meter I mentioned earlier, it looks like my old MFJ-941-E antenna tuner is also affected. So, I’ll have to replace the feet on those items and clean up the residue on the shelf with the mineral spirits. Needless to say, some of this equipment hasn’t been moved in years.

This wasn’t exactly how I wanted to spend my afternoon, but I’m glad I spotted the problem.

72, Craig WB3GCK

Handie-Talkie or Walkie-Talkie?

By: Bob KØNR
22 September 2024 at 23:47

In ham radio, we often use Handie-Talkie or HT to describe a compact, handheld transceiver. My first exposure to the term Handie-Talkie was when I first became a licensed radio amateur in 1977. While I was a student at Purdue University (W9YB), the absolute coolest VHF radio to have was the Motorola HT-220. Even a used one commanded a high Continue reading Handie-Talkie or Walkie-Talkie?

The post Handie-Talkie or Walkie-Talkie? appeared first on The KØNR Radio Site.

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Handie-Talkie or Walkie-Talkie?

By: Bob KØNR
22 September 2024 at 23:47

In ham radio, we often use Handie-Talkie or HT to describe a compact, handheld transceiver. My first exposure to the term Handie-Talkie was when I first became a licensed radio amateur in 1977. While I was a student at Purdue University (W9YB), the absolute coolest VHF radio to have was the Motorola HT-220. Even a used one commanded a high Continue reading Handie-Talkie or Walkie-Talkie?

The post Handie-Talkie or Walkie-Talkie? appeared first on The KØNR Radio Site.

💾

Handie-Talkie or Walkie-Talkie?

By: Bob K0NR
22 September 2024 at 23:47
The Motorola HT-220 Handie-Talkie

In ham radio, we often use Handie-Talkie or HT to describe a compact, handheld transceiver. My first exposure to the term Handie-Talkie was when I became a licensed radio amateur in 1977. As a student at Purdue University (W9YB), the absolute coolest VHF radio to have was the Motorola HT-220. Even a used one commanded a high price so they were out of my price range and I never owned one. These were 6-channel crystal-controlled transceivers…back then you had to set up the radio with the particular 2m frequencies you wanted to use. Because it was such an iconic radio, there are many HT-220 enthusiasts still around with websites with tons of useful information. See the HT-220 Page.

Motorola trademarked the name Handie-Talkie and used that nomenclature for many years with its line of portable radios. However, this trademark has expired, so now Handie-Talkie is a generic term.

The First Handie-Talkie

But the HT-220 was not the first Handie-Talkie, so I started poking around to find out how this name originated. Back in World War II, the SCR-536 was a portable “hand-held” transceiver developed in 1940 by Galvin Manufacturing (later Motorola, Inc.)  I put “hand-held” in quotes because, by today’s standards, it was a Hand FULL. But most people consider the SCR-536 to be the first modern, self-contained HT transceiver. The Wikipedia article for the SCR-536 describes the radio quite well. The radio put out about 360 mW of RF power on 3.5 and 6.0 MHz (Oops, I mean 3500 to 6000 kilocycles) using Amplitude Modulation (AM). The circuitry relied on smallish vacuum tubes, creating quite a design challenge. Motorola has a page on its website that talks about the origins of the radio. IEEE Spectrum also published an excellent article: The SCR-536 Handie-Talkie Was the Modern Walkie-Talkie’s Finicky Ancestor. The January 2005 issue of QST has an interesting article by Gil McElroy, VE3PKD, A Short History of the Handheld Transceiver. It provides more history and insight into this fun topic.

The SCR-536 Handie-Talkie

 

 

 

 

 

 

 

 

 

The First Walkie-Talkie

A few years later (1942), a backpack portable radio was introduced, called the SCR-300. I always assumed that the backpack-style radio would have come first and the more compact radio SCR-536 would be later. (Actually, there were previous backpack radios, such as the SCR-194). This new backpack-style radio was referred to as a Walkie-Talkie. According to the manual, the SCR-300 was “primarily intended as a walkie-talkie for foot combat troops”. I suppose the emphasis was on how you can walk and talk, with a radio on your back.

The SCR-300 Walkie-Talkie transceiver.

This article: SCR-300 WW2 Radio Backpack: The “Walkie Talkie” That Shaped the War describes this radio as a game-changer for frontline troops. The radio weighed a heavy 35 pounds, and used Frequency Modulation (FM) on 40 to 48 Megacycles.

Of course, with technology development, there is always the question of “who was first”? The SCR-194 that predated the SCR-300 might be considered the first walkie-talkie. However, the SCR-300 and the SCR-536 seem to get all of the glory, probably due to their impact on the war effort. However, take a look here if you want to dig deeper: TALK the WALK or WALK the TALK: Who actually developed the first Walkie-Talkie?

This article describes the development and use of the SCR-300 and mentions some of the limitations of the SCR-194: SCR-300 History Development Employment and Details Final Draft This is a big file with many photos but worth reading if you have the time.

Today’s Terminology

The Yaesu FT-4X handheld transceiver

Fast forward to today and we see that the HT and Handie-Talkie nomenclature is common in the amateur radio world. The photo to the left shows a modern 2m/70cm HT, the Yaesu FT-4X.

The term “walkie-talkie” has morphed to something quite different and is used generically to describe a handheld radio. This term covers a wide range of radios, from low-cost Family Radio Service (FRS) radios to higher-quality professional radios. This is quite different from the original Walkie-Talkie, a backpack radio weighing 35 pounds.

The military has progressed with improved communication technology, still using backpack-style radios, now referred to as manpack radios. These are amazing radios that pack extensive capability into a relatively small package. The AN/PR-158 shown below covers 30 to 2500 MHz in frequency, satellite comms, advanced encryption, narrowband and wideband modes: AM, ASK, FM, FSK, PSK, CPM, GMSK, and plenty more. This radio weighs 12.7 pounds with the battery installed, so a lot lighter than the old SCR-300.

A modern military manpack radio (AN/PR-158)

So that’s a quick tour through some radio terminology along with a bit of historical perspective. I discovered there is an infinite supply of information out there on the history and technology of military radios. If you want to dig deeper, go for it!

73 Bob K0NR

The post Handie-Talkie or Walkie-Talkie? appeared first on The KØNR Radio Site.

QU-21C Mini Paddles

By: WB3GCK
18 September 2024 at 14:23

I’ve been toying with the idea of putting together a small radio kit based on my (tr)SDX or something similar, so I’ve been looking at small paddles to go with it. Browsing through eBay recently, I came across several listings for the QU-21C paddles. They were inexpensive, so I thought I’d order them and give them a shot. 

These paddles are nothing new; they’ve been around for a few years. (I’m definitely no early adopter.) The QU-21C paddles are made in China and mine are marked with the brand name, Magic Rabbit. From other reviews I have seen, there may be other manufacturers. So, the quality and packaging may vary. I paid about $24 USD from a seller (iDrone) that ships from the U.S., but you can find them listed for less than $20, if you don’t mind waiting for a shipment from China. 

Opening the package, I found the paddles are even smaller than I expected. The base is approximately .98 inch by .98 inch (25mm x 25mm) and 1 inch (26mm) tall. The overall length, including the paddles, is 1.9 inches (48.5mm). On my kitchen scale, the paddles weighed in at 1.25 ounces (34 grams). The paddles appear to be 3-D printed, but the quality is pretty good. The base of the paddles is magnetic, which is one feature that first drew my attention. 

Magic Rabbit QU-21C paddles with the rubber pad attached to the magnet. The pad looks a little ratty around the edges, because I removed it and decided to put it back on. I messed it up a little in the process.
Magic Rabbit QU-21C paddles with the rubber pad attached to the magnet. The pad looks a little ragged around the edges, because I applied it, removed it, and then decided to put it back on. I messed it up a little in the process.

The package I received included:

  • Paddles with a magnet attached to the bottom
  • 3-ft cable with 3.5mm stereo plugs on each end
  • Hex wrench for adjusting contact spacing
  • Two adhesive metal discs
  • Adhesive rubber pad
  • Plastic storage case that holds everything
Some of the accessories that came with it. The cable is inside the clear plastic storage box. The adhesive discs can be applied anywhere, so you can use the attach the paddles magnetically.
Some of the accessories that came with it. The cable is inside the clear plastic storage box. The adhesive discs can be applied anywhere, so you can use the attach the paddles magnetically.

My first impression was that the contact spacing seemed a little wider than I like. I used the supplied hex wrench and adjusted the spacing until the contacts were completely closed. Then, I backed off a little. 

I prefer a light spring tension on my paddles, but the spring in these paddles seems stiffer than I’m used to. Unfortunately, there’s no adjustment for that. So, I’ll just have to get used to using a little more force than my other paddles. 

I’m not sold on the magnetic base, though. The square magnet is fairly strong, but it’s highly polished. So, the paddles sometimes have a tendency to slide when I’m sending. I applied the rubber pad that comes with it, but that seemed to offer only minimal improvement. For now, I just hold them in one hand while sending with the other.

I’ve actually thought about trying to remove the magnet altogether, since it appears to be glued on. At least, it wouldn’t be attracting every ferrous object that comes near it. But, for now, I’m just thinking about it.

The QU-21C paddles during a recent activation, along with my trusty Palm Mini paddles are also shown.
The QU-21C paddles during a recent activation, along with my trusty Palm Mini paddles.

I had a chance to use the QU-21C paddles on a recent park activation. It didn’t take long to get used to them, and I had no issues with them at all. The paddles keyed reliably, without missing a single dit or dah.

Even with my spring tension and magnet gripes, I’m pretty happy with these paddles. These cheap paddles look like worthy candidates for field use. We’ll see how well they hold up over time.

72, Craig WB3GCK

A Prequel

In yesterday's video we saw Alan W2AEW activate Washington Rock State Park with the CFT1 QRP Transceiver. Dummy me! I didn't realize that this is the newest offering from KM4CFT, who also sells the 9:1 UNUN kit that I recently built and put through a test run on Sunday.

Alan also has a YouTube video on the actual build of the kit. I am posting it here as a companion video - a prequel, if you will. It's a little long - close to 40 minutes, but is very interesting.


By the way, if you haven't subscribed to Alan's YouTube channel, you're missing out on a lot of great stuff.

72 de Larry W2LJ

QRP - When you care to send the very least!

POTAing on!

Good friend, Alan W2AEW does a POTA activation with a new QRP rig. 

Boy howdy! These new QRP rigs are popping up so fast, it's hard to keep up with them - what's new, what's what ....... WOW! Going to sound like an oldster, but I can remember when you could count available QRP rigs with the fingers on both hands. Pickin's were slim ...... no more!

Alan was at my favorite spot - Washington Rock State Park, in Greenbrook, NJ.

72 de Larry W2LJ

QRP - When you care to send the very least!

Upcoming Portable ops

By: VA3QV
12 September 2024 at 15:27

Its another gig sitting my “Grand Kittens” for my daughter as she and her hubby will be out of town from September 20th for a week. I guess I did a good job when they went to Cuba last January so I got invited back… I will be operating /p from Ottawa from September 21st to September 27th.

Most of my operating will be from September 23rd onwards.

As you can see from the above pic… they like having me around (one cat at least)

This time its a bit different because the car will be going with them to their rental cottage which is about 2 hours north of Ottawa.

However I plan to take both my Portable Station and my Transportable Station with me so I can activate some POTA locations with the Xiegu X5105 and also use my Yaesu FT 891 as I control the Trans Provincial Net for my 11am slot.


Before we go any further please remember that all my RF Plans you will see below are if the weather is good. I don’t like operating outside in the rain and neither do my radios….


The closest park to where they live is a City Park and not a POTA park.

The park has two sport fields and they have bleachers so it will be easy as I will have somewhere to sit along with strap my MFJ 33 foot mast to so the EFHW will have some altitude.

That will allow me to act as NCS with a 100w station with a full size antenna.

Once the net is over I will be packing up and heading back to the apartment for lunch. In the afternoons…. Once again if the weather is cooperating I plan to take the X5105 out to one or two of the local POTA Parks for a couple of hours. Check POTA Spots….

Due to the fact of not having access to a vehicle I will be heading out either on foot or public transport. After checking the POTA map it seems there are quite a few POTA sites that are fairly easy to access via the Bus and LRT service. However a few of the “Locals” have mentioned that they might pick me up and we could do an activation as a group so you never know.

They say that “getting there is half the fun” and this might be the case.

Stay tuned…

73bob

Yes its an old picture but the hobby has been fun since the 1990’s

Upcoming Portable ops

By: VA3QV
12 September 2024 at 15:27

Its another gig sitting my “Grand Kittens” for my daughter as she and her hubby will be out of town from September 20th for a week. I guess I did a good job when they went to Cuba last January so I got invited back… I will be operating /p from Ottawa from September 21st to September 27th.

Most of my operating will be from September 23rd onwards.

As you can see from the above pic… they like having me around (one cat at least)

This time its a bit different because the car will be going with them to their rental cottage which is about 2 hours north of Ottawa.

However I plan to take both my Portable Station and my Transportable Station with me so I can activate some POTA locations with the Xiegu X5105 and also use my Yaesu FT 891 as I control the Trans Provincial Net for my 11am slot.


Before we go any further please remember that all my RF Plans you will see below are if the weather is good. I don’t like operating outside in the rain and neither do my radios….


The closest park to where they live is a City Park and not a POTA park.

The park has two sport fields and they have bleachers so it will be easy as I will have somewhere to sit along with strap my MFJ 33 foot mast to so the EFHW will have some altitude.

That will allow me to act as NCS with a 100w station with a full size antenna.

Once the net is over I will be packing up and heading back to the apartment for lunch. In the afternoons…. Once again if the weather is cooperating I plan to take the X5105 out to one or two of the local POTA Parks for a couple of hours. Check POTA Spots….

Due to the fact of not having access to a vehicle I will be heading out either on foot or public transport. After checking the POTA map it seems there are quite a few POTA sites that are fairly easy to access via the Bus and LRT service. However a few of the “Locals” have mentioned that they might pick me up and we could do an activation as a group so you never know.

They say that “getting there is half the fun” and this might be the case.

Stay tuned…

73bob

Yes its an old picture but the hobby has been fun since the 1990’s

Modest?

 On Facebook, ON7RF provided a picture of his "modest" station.


Modest? Maybe in terms of $$$$$, but there's plenty enough there to work the world! Rene definitely has the right idea here - "Do more with less." You don't need an uber station or a kilowatt to work the world, and this is much more fun, IMHO.

Only thing I would change here is to use a paddle.  My wrist gets tired from using a straight key after a while.  Undoubtedly, it's probably just poor technique on my part, but I blame arthritis! LOL!

I saw this on a POTA FB page and saved the image for a closer look. Then I went to the webpage.

Portableflagpoles.com - they sell their drive on mast holder with two diameters. The larger one will accept masts up to 2.25" (about 6 cm) wide. The bottom cap of the Jackite is just a smidge over 2", so it will fit in there nicely. The mast holder is only $39 - the question is ...... do I really need it? I have to decide whether or not my homebrew mockup is worth keeping. It does the job all right, but it's nowhere as elegant a solution as this one. The other thing is that this one is metal, while mine is wooden. In the long run, I have to believe that this one would undoubtedly hold up better to being driven upon. And whatever I decide, I have to do it sooner, rather than later. Marianne and I are heading back up to Alexandria Bay soon and there are two parks up there that I'd like to activate.

When I worked at Sinar Bron, my boss who was a Swiss engineer, would always want the "most elegant" solution to a problem. Not necessarily the most elegant in appearance, but the best solution in terms of functionality, ability, dependability and sleek design (if possible, but not as necessary). I guess that's where that got ingrained in me.

He had a knack for bringing me down to Earth. When I would solve a problem that seemed to elude everyone else (even the factories who manufactured the equipment that we sold) he would say (in his thick Swiss accent), "Doo, Larry, even the blind pig finds an acorn every once in a while." Real confidence booster, right? Even so, I sorely miss those days. Working at Sinar Bron was probably the best 22 years I've ever spent at a job.

72 de Larry W2LJ

QRP - When you care to send the very least!

Articles: Scrappy circuits, ham radio inspires student, why measurements are important, why copper is important

By: Dan KB6NU
12 September 2024 at 10:30

Here are some articles I found intersting. The first details a cheap way to teach kids (and adults, too!) about circuits….Dan

Scrappy circuits

Circuit components made from dollar-store items.
Circuit components made from dollar-store items.

The best dollar you can spend on a child’s STEAM education is to take them to the dollar store, buy an electronic item, and then take it apart. Learning how a handheld fan, LED light, remote control, or headphones work will help show how wind turbines, traffic lights, speakers, keyboards, and other modern devices function.

The next step is to take apart a dollar store item and make it better — combine two items, replace a switch, create something new and unique. Scrappy Circuits is the perfect way to get started.

I first developed Scrappy Circuits with Chris Connors and Eva Luna while working at Xraise, an education outreach program at Cornell University. What began as an exploration of DIY switches ended later as a self-made invention system sourced from a fifty-cent LED tea light. Educators can build it with their class for about $20. Anyone with access to office supplies and a dollar store can make the five Core Bricks for about $1. Here’s how to create each one.

…read more


I think that we short-change ham radio’s usefulness in getting people to pursue STEM careers…..Dan

Ham radio inspired this Scranton University student to pursue engineering

Many college students participate in sports, listen to music, or play video games in their spare time, but IEEE Student Member Gerard Piccini prefers amateur radio, also known as ham radio. He’s been involved with the two-way radio communication, which uses designated frequencies, since his uncle introduced him to it when he was a youngster. His call sign is KD2ZHK.

…read more


I’ve always been something of a measurement nerd……Dan

Why measurements are important

Practically everything you use in your everyday life works because of measurement science. Without precise measurements, your car wouldn’t run, your phone wouldn’t work, hospitals couldn’t function, and the ATM would fail.

NIST is the national measurement institute of the United States. Most people in the U.S. have no idea that there is a single organization within the federal government that makes sure all measurements in the U.S. are correct and trustworthy — and that they are accepted by other governments worldwide.

…read more


Copper is one of those things that we take for granted…..Dan

Copper: Conductivity Benefits and Environmental Impact

Most circuit designers probably aren’t thinking about, much less worrying about, the metal copper. But as the electrification of the world continues, copper conductors used in applications from microchips, other components and circuit boards, to household, industrial, and automotive wiring, and critical workhorses like batteries and electric motors, points to the need to spotlight its starring role.

…read more

Dusting Off My Z-Match

By: WB3GCK
8 September 2024 at 12:22

I was recently looking at some of my older gear gathering dust on the shelf, so I resolved to start putting it to use. So yesterday, before I headed out for Ridley Creek State Park (US-1414, KFF-1414), I grabbed my old homebrew z-match antenna tuner and gave my Elecraft T1 tuner the day off.

I built this tuner from scratch about 24 years ago, and it has always been one of my favorite projects. Based on a bunch of different designs, it gave me years of great service. For years, my go-to portable rig was my old FT-817 coupled with this tuner. Today, I paired the z-match with my Penntek TR-35 (5 watts, CW). I used my 12-foot whip and homebrew loading coil mounted on the truck. The loaded whip’s SWR on 40M and 30M is just slightly high, nothing the old z-match can’t handle. 

My old homebrew z-match ATU along with my TR-35
My old homebrew z-match ATU along with my TR-35

I’ve been spoiled using automatic antenna tuners lately, but tuning the z-match was a cinch. Just peak the received noise, switch in the resistive SWR bridge, key up the rig, and tweak the knobs to extinguish the LED. Then switch out the bridge and go. 

The z-match is a high-Q, narrow bandwidth device, so when changing frequencies on a band, I did a check with the SWR bridge before transmitting. It just took a minor tweak to extinquish the LED again.

It was a pretty good day on the bands. I split my time between 40M and 20M. I ended up with 28 QSOs. Among them was one park-to-park contact and one DX contact (IW2NXI). I forgot my water bottle, so my parched throat (and famously short attention span) prompted me to pull the plug after an hour on the air. Activation #20 from US-1414 was in the books.

My homebrew z-match was an integral part of my portable setups back in the day. In this picture from 2001, I was using it with a doublet fed with TV twinlead.
My homebrew z-match was an integral part of my portable setups back in the day. In this picture from 2001, I was using it with a 40M doublet fed with TV twinlead.

My little Elecraft T1 tuner certainly has a size and weight advantage over my homebrew z-match. It’s certainly is easier to use, too. However the z-match can handle both balanced and unbalanced loads, and it doesn’t need a battery.

I have some other old gear in mind for future activations. A couple of rigs could make for some challenging activations.

Stay tuned.

72, Craig WB3GCK

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