Category Archives: Hams

Dan’s clever chalk line homebrew EFHW antenna

Many thanks to Dan (KQ8Q) who writes:

Hi Tom,

I discovered something you might have an interest in for your wire antenna deployment. Years ago when I was a building contractor, we used chalk line for floor layout. It has a very high tensile strength and is very light weight. After reflecting on this, I recently bought a 100’ spool of braided 1 millimeter chalk line and used it for a field deployment. I attached my “throw weight” to it and easily launched it about 60’ into a tree. You can see it in the attached photo holding my homebrew EFHW to my Jeep.

This link is what I used: Tajima PL-ITOL 100 ft .04″ Bold Braided Replacement Chalk Line New | eBay

Click here for full parts list (PDF)

The magnet wire was scavenged from a HUGE transformer from a neighbor’s discarded light fixture.

Lug Nut Throw Weight: left hand threaded from a 1966 Plymouth Fury

I did the new installation for him and he gave me the old one. I promptly disassembled it and collected miles of 14 and 20 gauge magnet wire ?!

I haven’t added the capacitor to this antenna yet because it is sufficiently resonant and broadbanded on 40, 20, 15, and 10 Meters. I did some testing with the capacitors though on my previous build which was the PVC tube EFHW transformer. I believe I may have sent you a photo of that in a previous message. It too was resonant in the same places, but adding the capacitor smoothed and widened the acceptable SWR range.

The attached photos are my complete antenna assembly: matching transformer (49:1), 65.5’ speaker wire, 100’ braided 1MM chalk line, and throw weight (epoxy filled lug nut with short paracord pigtail).

Compact and lightweight.

Dan/ KQ8Q

I love this, Dan! I also like how self-contained and compact it is. What a professional job, too, with heat shrink, proper connection points and tie-offs.

Brilliant work!

Do you have an antenna or radio project you’d like to share on QRPer.com? Contact me!

Guest Post: Creating pick and pluck inserts for radio cases

Many thanks to Mark Hirst, who shares the following guest post:


Pick and Pluck Foam

The old adage of ‘measure twice and cut once’ is very apt when using pick and pluck foam. The inserts are not cheap and mistakes are hard to rectify.

Whether you are preparing a large case with several items in a shared insert, or focussing around a single item, planning the layout is key.

Item weight is also a factor to consider, as this will affect decisions on wall thickness between items and the case.

Finally, how hostile is the environment likely to be? Is the case going in your backpack or car where you’re in careful control, or is going to be subject to careless handling by others?

Planning the layout

Once you’ve settled on a case size and how much padding you need, a non-destructive way of planning the layout is to use cocktail sticks.

These can be inserted into the corners of the foam segments to trace the outline of the radio and any items such as controls and ports that may extend from the body.

Since the size of the segments is in fixed increments, matching the exact dimensions of the radio is down to pure luck. I would go for a slight squeeze on the radio body if feasible to make sure it’s always in contact with the foam, but give some breathing room around the controls and ports.

The example below is a case I use for backpack transport. It has rather thin but adequate side walls for that purpose. I prioritised wall thickness facing the front and back of the radio, and also on the side opposite the carry handle. Note how the foam comes right up against the body of the radio, but leaves the front controls with some clearance.

Outlining using cocktail sticks

This has the benefit of keeping any sudden shocks away from the controls, and also reduces the number of places where foam is subject to tearing and compression when the radio is inserted and removed.

The completed insert

Separating the foam

The best place to start is along the planned route of a long side wall. Use your thumbs to separate the surface of two segments on one side from two segments on the other.

Once the surface tear has got going, you should be able push a finger down between the four segments, extending the tear till it reaches the bottom of the foam. At this point, you have a cut all the way through.

Separating the foam

Now you can peel the foam apart at the upper surface in each direction, using your forefinger to again push down between the segments to complete the separation down to the lower surface.

Work carefully around the cutouts and protrusions accommodating the controls. The protrusions are potential weak points at this stage, so be sure to proceed slowly.

If you need to practice, you can always start by separating segments deep within the section that will be removed till you get the hang of it.

Reinforcement

While pick and pluck means you don’t need special tools or templates to cut the foam, the remaining material in your insert is inherently weaker than a solid structure.

The solution I’ve used is to fill the residual cuts with a solvent free adhesive. Solvent free adhesives are often aimed at children for safety reasons, and while there are solvent based adhesives for foam, the one I used dries clear with a resilient flexible bond that is stronger than the foam itself.

I run a finger gently along the exposed walls, edges, and around the protrusions. This makes the potential weak points and stress areas immediately apparent as segments naturally separate along the pick and pluck cuts.

Armed with a tube of adhesive and a finger (usually a thumb), you can gently open the weak point and then run the nozzle of the tube down the cut, dispensing generous amounts of adhesive as you go. The two sections of foam close up as the nozzle passes by, with the adhesive soaking into both sides. As long as you don’t go overboard, the adhesive will stay within the join and you won’t have to wipe away any excess.

Reinforcing corners

Side walls are not subject to the same stress as protrusions, but you will probably still spot sections with deeper cuts that need attention, and you will definitely want to reinforce the corners.

Reinforcing sidewalls

I’ve allowed at least a day to be sure the adhesive has set. It’s worth going over the insert again to see if you missed anything the first time round.

The Adhesive

The Bostik solvent free adhesive resembles runny white toothpaste when dispensed from the tube, but dries clear when set.

Inevitably, when I tried to find more of it recently, I discovered that the easily recognisable colour and branding had made way to a confusingly generic scheme shared across a variety of different adhesive types from the manufacturer.

I found this old listing for Bostik 80518 on Amazon UK, and another here on Amazon US. Based on the product number, a modern equivalent seems to be here.

I’m sure there’s nothing unique about this particular product, other than I’ve found it to be foam friendly over the years. Aside from being solvent free, its ability to seep into the foam is a key asset.

Since the first step of creating an insert leaves you with a potentially discardable piece of foam anyway, you have plenty of raw material to experiment with if in doubt.

Additional Reinforcement

Even if you have been generous with the side walls of your foam insert, a heavy radio might demand some additional work to ensure the longevity of the foam.

While the example case shown above worked OK to start with, I noticed that the floor of the case and the side wall facing the back of the radio were taking a beating.

The problem was caused by the feet of the radio, cooling fins, power and antenna connectors. During transport, these were pushing into the foam with the full weight of the radio behind them. Subject to such concentrated point forces, I could see that the foam wasn’t going to last.

Using very thin and very cheap flexible plastic cutting boards from my local food market, I cut out panels which spread the point compression across a much wider area.

Additional Reinforcement

Now when I put the case into a backpack, I ensure that the radio is sitting on its tail with the cooling fins against the rear panel.

Conclusion

While it’s possible to create ad-hoc transport solutions for radios, there’s nothing quite as satisfying as a sturdy padded case that is made to measure. The cases are forever, but the foam needs care and attention, so I hope these tips help you build a lasting solution for safely transporting your pride and joy.


Oh wow! Thank you so much for this timely post and for helping me as I kit-out a Pelican case for my Icom IC-705.

Readers, click here to check out Mark’s previous post about the case he uses for his Yaesu FT-891.

Thanks again for sharing your best practices, Mark!

Mike rediscovers radio and POTA “gently reopened the door to an amazing hobby”

Many thanks to Mike (W6MVT) for sharing the following guest post:


Back to Ham Radio for a Year – A Brief Reminiscence

by Mike (W6MVT)

This story will sound like many I have heard over the past year, but I will write it nonetheless as a note of gratitude.

Last March COVID had just restricted our activities and I was wondering how to spend my time. I had received my licenses back in the 80’s. There was a code requirement, there was no internet, no QRZ, no spotting.

Though I enjoyed ham radio very much, family and work took precedence, and the equipment went into storage. I eventually sold it off (who is dumb enough to sell matching Drakes?).

Fast forward to the around 2010, when I knew I would be retiring and might want to get on the air again. I picked up some used equipment and stashed it away without really using it.

Then 2020 arrived and the world changed dramatically. One day, prompted by who-knows-what, I had the bright idea to dust off the gear and hook it up, mostly to see if it even still worked. A makeshift wire in the back yard and a quick listen and there it was – a CQ.

I was actually nervous to answer – it had been that long. It was KE8BKP, who it turns out, was activating a park. I hadn’t a clue what that meant, but I shakily answered. We exchanged reports and he went on the to the next one. I had two immediate reactions. First, I was reassured by that brief, painless interaction. The stuff worked and I could still “do this.” Second, things had changed a great deal since the “old days.” But I researched POTA and SOTA and DX Clusters and all the other magic that now exists.The point is that POTA gently reopened the door to an amazing hobby, one that still fascinates me. I went on to become an active hunter and now a prolific activator.

Since it has been a year now, I felt it important to acknowledge this moment, and to note one more thing. When an activator answers a call, we don’t know the other person’s circumstances. Maybe they are a new – or returning “old” ham. Maybe it took courage to key the mic or pound the key. I have appreciated the manner in which POTA hams enthusiastically help one another improve, learn and in turn help others. Thanks to Jeff, KE8BKP, and all the others since, and to come. And thanks to the many volunteers that keep the program running each day.

73, and be well,

Mike W6MVT


Mike, I couldn’t agree with you more. I think all POTA, WWFF, and SOTA activators are essentially ambassadors for ham radio. We never know what’s happening on the other end and I strongly believe in patience and understanding when answering calls and performing an exchange. It can have a huge positive impact for the person on the other end.

So glad you found Parks On The Air and that you’re enjoying playing radio once again!

Thank you for sharing your story.

Steve’s new Icom IC-705 SOTA lap desk

I’ve been in touch with Steve (WG0AT) recently. He happened to be selling his FT-817 at the same time I was looking for a narrow CW filter.  The stars aligned and I now have a 500 Hz Collins CW filter in my FT-817ND.  Thanks, Steve!

Steve also took delivery of his Icom IC-705 recently so we’ve been trading notes about this fine rig. He and I both have a fear of the ‘705 falling off our laps when using it in the field for SOTA and POTA activations.

Steve, being the king of ham radio customization, started working on a portable desk. He shared iterations along the way and his final product seen in the photo above.

The desk is a brilliant design: it’s lightweight, sturdy, has holes for managing wires/cables, a strap to hold it your leg, and even a cup holder. The cup holder is a bit of genius because he likes a good cuppa tea in the field just like I like a good cuppa joe.

The IC-705 will be able to bolt directly to the lap desk so there’ll be no fear of it falling off a cliff in the field.

Of course, the desk will work with any field-portable radio. Steve shared a few more photos:

I’m going to attempt to build a similar desk for my IC-705. The great thing about it is it’ll easily fit in a backpack, too.

Thanks again for letting me share your photos, Steve! We look forward to seeing this desk in action at a summit near you!

Check out Steve’s excellent YouTube channel here.

Adding CW mode to the EA3GCY DB4020 Dual-band 40 and 20M QRP Transceiver Kit (Part 2)

Many thanks to SWLing Post contributor, Frank (ON6UU), who shares the following guest post which expands upon his previous DB4020 article:


The EA3GCY DB4020 transceiver now has CW mode

by Frank Lagaet (ON6UU)

After telling you all about the DB4020 SSB build I’m here with the CW part of the kit,  let’s say this is part 2.  At a certain moment Javier let me know the CW interface kit was ready for shipment and some week later it was delivered to my QTH.

Again, a well packed kit arrived in a brown envelope, components and boards well packed in bubblewrap.  I found even a board I did not expect which can hold a push button,  a switch and the connector for your morse key.  Javier thinks of everything it seems!

Unpacking the bubblewrap gave me this result,  all components in 2 bags.  In the bigger bag another 2 bags with 2 printboards,  one for the CW interface,  one for the CW filter.  Great !!  Checking the material bill resulted in all components there,  another thumbs up.

I started, of course, immediately building it because I wanted CW in the transceiver as soon as possible.  I don’t do much in SSB mode anymore and I already started missing CW on the DB4020,  so I started my KX3 to listen to while I was populating the boards.  I never thought CW was going to have this impact on me! …. ..

I started building the CW interface,  again starting with all small items.  I soon saw that the 2 relays which need to be soldered in were ideal to protect all components when the board is upside down, so I soldered them in very quickly.  I then soldered in all other components ending with the elco’s.

Next phase was the CW filter.  This board is small and came together in a blink of an eye, no problems there, the long legs of the 3 and 4 pin headers went in last.

The following day, I made all wire connections and soldered a 13pin connector,  leaving one pin out since I want to have the option to choose the width of the CW signal I’m listening to.  By cutting the FL CW + pin and adding an additional switch, I have now 500Hz or 2400Hz.  Great option, for very little effort and simple.  Another thumbs up here.

Now it was simply a matter of inserting the sub boards in the main board and all should be working.  And it did!  Hurray!  The 500Hz filter works perfectly,  filtering away all above or below stations nearby my operating frequency.

This is the result of the soldering work,  2 small boards which need to be inserted in the main board:

The CW interface still needs the 13pin header of which I cut one pin and mounted a switch to have the 2400Hz width.

The IC you see in the middle of the CW interface is the KB2 keyer which gives you several functions like 4 memories and beacon mode.  The 4 potmeters are used to set the level on 40 and 20 meters,  to set the delay between TX and RX switchover and to set side tone monitor level.   The keyer also provides functions as keyer mode A or B,  straight key function and can be set for speeds between 1 and 50WPM.   WPM speed can be set in 2 different ways.  Handy!

Here a picture of the CW filter inserted on the main DB4020 board.

The CW interface is inserted at the side of the main board,  notice the 2 wires which go to the switch to allow switch-over between 500 and 2400Hz.

(Wiring still needs to be cleaned up in this picture.)

Finally, the result:  a good working multimode QRP transceiver with 2 bands.  It should be possible to make close to medium range with it as well as DX,  even with QRP power.

And while I was building I also made a new key for this radio,  it is made out of a relay and cost nearly nothing,  looks good doesn’t it ?  hihi.

Homebrew key

The key, when in practiced hands (fingers hi), can do 50 WPM without a problem. My friend HA3HK does without blinking an eye at 40WPM with this kind of key and tells me that he can go faster if needed.  Me? I’m going it a bit slower.

Battery pack

As this radio is only using little power (0.4A in RX,  1 to 2A in TX depending the power you set it) I thought,  let’s make a battery pack for the radio.

The first plan was installing it in the box.  I did not do that because the batterypack is also powerful enough to feed my KX2 and other QRP transceivers. Since I can use it with all of them, a loose battery works out better for me.

I started with an old laptop which had a broken screen and some other malfunctions,  but still had a good battery,  although I needed the battery connector of course.  A piece of wood to mount the connector on was my next goal.  And since I still have another laptop using the same batteries, I can charge the battery without problems.  Simple, but good and it weighs much less than a gel cell battery.

The battery provides me with 12.5V and some 5Ah.  Enough to last for hours on RX and for sure good enough to activate 2 SOTA sites in one day.   It doesn’t look great but works great– that is what matters and to test it was more then good.  Next will be getting the battery pack in a nice box.  Better to re-use stuff than throwing it away I’m thinking.

I need to do something about the cover of the OLED display,  there is still some work there to make it look nicer.

Some video can be seen on YouTube :

Finallym I’d like to thank you all for reading my articles about the DB4020. I had big fun soldering, tinkering with the box, making the key, and batteryholder/batterypack.  My Hungarian friend HA3HK told me it looks a bit like a spy radio. …. ..

I also include one more time the link where you’ll find this kit :

https://www.qrphamradiokits.com/

73 TU ee

Frank

ON6UU


Thank you so much, Frank. No doubt, you had a lot of fun putting this excellent little kit together.

Implementing a filter switch was a fantastic idea and, obviously, not terribly difficult to do.

Based on the videos, the DB4020 has a low noise floor and very good receiver characteristics. I’m impressed that the CW portion of the radios has so many features as well, such as a memory keyer and beacon mode.

I also love how you reused that 5Ah laptop battery! I think that could almost give you a full day of SOTA activations at those consumption levels!

Thanks again for sharing this with us, Frank! We look forward to your future articles!

Silent Key: Marshall Emm (N1FN) owner of Morse Express, Oak Hills Research and Ameco

Many thanks to Dennis (K2DCD) who shares the following from the Fireflies QRP Group:

We are sad to announce that Marshall Emm, N1FN – long time QRP advocate, owner of Morse Express, Oak Hills Research and Ameco – is a Silent Key. Marshall passed away peacefully Monday morning, February 17, 2020, at Aurora CO Medical Center with his daughters and wife surrounding him. When more details are available, we will post a more comprehensive announcement. Our thoughts and prayers are with Marshall’s family. Messages, thoughts, stories can be sent to [email protected].

Dick AB0CD.

Thank you for sharing this sad news, Dennis. Rest In Peace, Marshall.

On The Air: ARRL’s excellent magazine for newcomers…only available behind their paywall

Cover of the new “On The Air” e-magazine from the ARRL

[Please note: this is a cross-post from our sister site, the SWLing Post.]

Today, the ARRL released their new electronic magazine for ham radio newcomers: On The Air.

The ARRL describes On The Air‘s mission:

“On the Air magazine is the newest ARRL member benefit to help new licensees and beginner-to-intermediate radio communicators navigate the world of amateur radio. Delivered six times a year, the magazine will present articles, how-to’s, and tips for selecting equipment, building projects, getting involved in emergency communication as well as spotlighting the experiences of people using radio to serve their communities, and those using it for enjoyment.”

I checked out On The Air and was quite pleased with the scope of the magazine. The first issue covers topics such as: understanding the ionosphere, choosing your first radio, building simple antennas, and much more. I love the fact that the articles are written with newcomers in mind, too; less technical jargon and more explanations.

I mentioned in a previous post that I’ve been teaching a ham radio class to a group of high school students. Most of the students have now acquired their Technician licenses, and we’re even plotting a General class course for the fall.

Last month, I shared some copies of QST (the ARRL monthly member magazine) with my students. While they enjoyed looking through the pages of QST, many told me they simply didn’t understand the articles yet…There’s just not a lot inside a QST issue to grab the attention of a fifteen or sixteen year old who’s just gotten her ticket. Understandable.

Then, I learned about On The Air from a friend with the ARRL.  I was so glad to hear that the League was finally making a bi-monthly magazine aimed squarely at newcomers! I was also pleased it was an e-publication, because it will be that much easier to share with my class and propagate to prospective students.

But today, I discovered, to my dismay, that other than the premier issue, On The Air is for ARRL members only. Here’s a screen grab from the website:

But…”for members only”––?

Alas, in limiting access, the ARRL has essentially insured that most of their target audience won’t ever have the opportunity to read On The Air, and thus they’ve crippled the best ARRL recruitment tool I’ve ever seen. 

What a shame.

I’ve contacted my ARRL representative and asked that they reconsider the decision to hide this brilliant magazine behind a membership paywall. I’m pretty sure that ad revenue and membership fees could readily cover the cost of publishing this electronic edition. After all, On The Air could lead to a lot more ARRL members! And, indeed, I hope it will.

If you feel as I do, please contact your ARRL Section manager. It may be that those making the decisions are, in this case, a little out of touch with the future of amateur radio.

Update – To be clear about this post: I’m not implying anything bad about the ARRL here, I just think it’s a lost opportunity if they keep future editions of On The Air behind the member pay wall. I imagine that ad revenue alone could more than support this niche publication if they simply release it as a free PDF. The real benefit, though, could be an increase in ARRL membership as On The Air readers get a taste of what the League could offer! In other words: this is an opportunity!

What do you think? Should On The Air be free to anyone interested in amateur radio, or for members only? Please comment!

Reverend George Dobbs G3RJV Silent Key

We’ve lost an iconic man in the world of QRP: the Reverend George Dobbs G3RJV.

(Source: ARRL News)

The founder of the GQRP Club and Amateur Radio author the Rev. George Dobbs, G3RJV, of Littleborough, England, died on March 11. He was 75. Dobbs was reported to have been in ill health for some time and had been living in a care facility, where his condition deteriorated quite rapidly over the past few days. He was the honorary secretary of the GQRP Club (G5LOW), which he founded in 1974 to cater to those interested in low-power Amateur Radio communication. Dobbs served as the editor for the club’s quarterly, SPRAT. Dobbs was the author of QRP Basics, The International QRP Collection (co-authored with Steve Telenius-Lowe, 9M6DXX), and Making a Transistor Radio. He was a frequent Hamvention® attendee, and in 2015, he received the Hamvention “Technical Excellence Award.” — Thanks to Lee Boulineau, KX4TT

This African ISP commercial may be the best amateur radio promotion. Ever.

Many thanks to my buddy Ulis (K3LU) for sharing this brilliant commercial:

https://youtu.be/hxU1ZhINaHk

April 18 is World Radio Day

IARU logo

Friday, April 18, is the International Amateur Radio Union (IARU) “World Radio Day”. The theme for World Radio Day 2014 is “Amateur Radio: Your Gateway to Wireless Communication”.

World Radio Day is celebrated each year on April 18 to recognize the anniversary of the founding of the IARU in 1925. The first president of the IARU was Hiram Percy Maxim, 1AW.

Learn more about World Radio Day:

http://www.arrl.org/news/amateur-radio-your-gateway-to-wireless-communication-is-world-amateur-radio-day-2014-theme

http://www.iaru.org/world-amateur-radio-day.html

Learn more about the IARU:

http://www.iaru.org/