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How Signal Sticks are made

For some time I’ve been debating the idea of sharing a bit of the “behind the curtain” of how Signal Stuff as a company and Signal Sticks as a product work; there are a lot of reasons for and against the idea, but my hope is that by adding some clarity around my business it will add some value to the Ham Radio community:

Who is Signal Stuff?

First, while I often use the term “we” when I talk about Signal Stuff in order to make it feel more like a company — for the most part, Signal Stuff is actually a single person. Specifically, my name is Richard Bateman, KD7BBC.

Now don’t get me wrong — it’s not important to know that because you need to know much about me specifically, but I do want people to realize that in order to understand that it is possible to create a company in the ham radio industry with a small group or a single person.

Legally speaking, Signal Stuff is actually HamStudy.org LLC — however, the HamStudy name needs to be agnostic in terms of products and distributors, so we came up with Signal Stuff and the other names (Super-Elastic Signal Stick) somewhat grew naturally out of that.

There have been many other people who have volunteered time to help me, for a time I hired someone to help with shipping and customer service, and in general I often consider Signal Stuff to be supported by a lot of people, but I think often people look at Signal Stuff and think it’s a big company — it isn’t =] If I go on a family vacation I have to put up a note that shipments will be delayed because they run out of my basement :-)

Building Signal Sticks

Okay, enough about the boring stuff. I had someone ask me recently if Signal Sticks were really “hand made” as is claimed in our marketing materials, so let me show you a bit about how it works! The paranoid part of me is worried that I’ll lose business by doing this — what if people realize they could do it themselves? But really the basic design is one that has been known for a long time — it’s just a quarter wave “piano wire” antenna.

I should also mention that I no longer do all of this myself — I have hired a local assembly shop who makes most of the black antennas and I mostly do just the colored ones since those are harder to order with enough advance notice to have them done externally. That said, they use the same parts and steps, so this all still applies =]

Step one: Apply heat shrink

This is one of my custom-build heat shrink trays and the wire above ready to put on the trays.

One of the most interesting things about building these is that while making one isn’t hard, it gets a whole lot harder when you are making hundreds of them. The first year I sold these online I think I sold about 300 antennas — which was huge, I couldn’t believe I sold so many. In the first three quarters of 2022 I have sold almost 10,000 antennas — that is a *lot* of antennas to make without special machines.

The wire is purchased pre-cut and specially treated so that the adhesive will bond better. Care has to be taken to ensure that oils from our skin doesn’t get on the wrong part of the wire, otherwise the adhesive may fail and the antenna will need to be replaced.

In the picture above you can see one of the custom heat shrink trays that I designed and made — I designed it in Fusion360, milled the parts on my CNC machine, and then assembled. Each one holds 20 antennas and it has to be able to handle 325°F. It would take *way* too long to apply the heat shrink using a heat gun (believe me, we used to do it all the time and it was … painful. sometimes literally…), so a few years ago I purchased a heat shrink tunnel such as is used for shrink wrapping products.

You can clearly see in all of these pictures that I am habitually organized and neat….

The trays hold the wire with the heat shrink and keep the shrink far enough back that the adhesive can still bond to the wire, rather than just to the heat shrink. The heat shrink itself is custom ordered (I had to buy over 60KM of heat shrink to manage that…) to be thicker and tougher than the stuff you’d normally buy at a store. I have a heat shrink cutter that I had to buy to cut the shrink to the correct length. We learned an important lesson about safety one year when my oldest son cut about 1/4″ of his pointer finger off and we had to go get it stitched back on at the ER on Christmas Day…. so if you ever get one, always turn it off when loading or unloading *PLEASE*.

Step two: Clean up heat shrink

After shrinking them the wires have heat shrink sticking off the end; you might naturally think that one could just figure out the correct length so that doesn’t happen, but in practice there is too much variance in the rate of expansion for that to be viable. Instead it needs to be trimmed off the end — and if we don’t want the tip to come off easily then there needs to be a little bit of wire exposed so that the adhesive can bond to it.

I have tried making tools to help with this step but for me at least they always take longer than doing it by hand with my leatherman.

This is one of the first steps where you wouldn’t expect there would be all that much skill involved, but after doing literally thousands of these I find I’m able to trim 3-6 at a time where most people end up just doing one or maybe two at a time. You would think that using a razor/utility knife would work better but I find my leatherman to be the best tool for the job — which is convenient, since I always carry it. I have found that I can do this step faster than any other person I’ve trained, so when time is tight this is one of the steps I do myself even when I have help.

A little exposed wire must be left at the end, otherwise when we bond the tips they will only bond to the heat shrink and will come off if the shrink stretches.

This doesn’t look all that hard, but keep in mind that with this particular build I didn’t need to just trim three of them — I was out of stock on a number of different colors and styles, so I was building about 400 antennas that day.

Step three: Install the center pins

I have tried a lot of different ways to install the center pins over the years — crimping, soldering, wire glue, …. but soldering takes too long and wire glue is not effective enough. Finally I ended up getting custom connectors made which allow me to crimp them all with the same tool, which has made things much simpler.

These are BNC pins

Here is another step where one isn’t a big deal, but have you ever sat down and tried to crimp RF connector pins onto 400 wires? These days I use a pneumatic crimp tool, but it’s still definitely a time consuming process. There are of course different pins for each connector type, plus two different sizes of wire because I use smaller wire for both 440 and 220 monoband.

Step four: Prepare and then install the connectors

The connectors that I use originally were just regular RF connectors for coax which happened to fit the wire size I needed, but at this point they have been customized to better fit the plastic covers I designed for them and also to use the same parts for both sizes of wire. While I realize it’s generally taboo to discuss financial details on an open post like this, my last order for connectors and adapters I had to split into two payments because the processor I used could not send more than $20,000 per day. It’s a weird feeling when your orders get into that range and you’re still building these in your garage….

This is two steps in one because before putting the connector on the antenna you first need to install what I call the “glue cap”. The glue caps have gone through more iterations than any other part of this process — when I bought my first 3d printer back in … 2017, I think? … I immediately realized that I needed a way to justify the purchase. (that’s the healthy order to do things in, right?). One of my brainstorms — and likely the single most impactful brainstorm of my life — was that perhaps I could use them to make it easier to build antennas. That single thing completely revolutionized my antennas.

Once that’s all ready then the wire can just be inserted — though we do need to make sure it’s inserted all the way. After one memorable build night with volunteers I found 83 antennas which did not have the center pin inserted all the way after the adhesive had fully cured. It was not cost-effective to rebuild them, so I ended up needing to just throw them away.

The purpose of the glue cap is to hold the adhesive (technically not glue =]) in place while it cures (not dries…) so that it will bond to the correct parts of the antenna to make things come together. Every glue cap for every signal stick ever sold with a 3d printed cap was printed on one of my 3d printers in my basement. That said, I expect by the end of 2022 I will be making all the antennas using injection molded parts — they look better, are easier to use, and while the total cost will probably exceed $20K to make all the molds I have finally decided it’s time to just do it.

Final step: Apply the adhesive

It’s important to keep your work area organized so you can cleanly organize everything when it’s ready for adhesive

At this point they are technically usable, but they will also come apart if you pull on the wire much at all. The final step is to inject a 2-part adhesive into the hole on the side of the connector. We used to mix the adhesive is a small cup and use popsicle sticks to apply it before sliding the cap on, but that required a lot of skill to get right and we still had a lot more manufacturing defects. This leaves a slightly unsightly hole on the side, but it is more reliable — and that has always been the overriding goal for me.

This is the final step and it is both the most important and also the most difficult to do correctly. If you get too much adhesive in then you have to clean it off — and if it somehow gets onto the threads that might not be possible. If there are any issues and you don’t catch them during this step they cannot be fixed.

There are also two sides to this task — first, you need to inject the adhesive, and then you need to do any cleanup needed and also install the tips, which these days are also injection molded.

These are two of my helpers — Dallin and Ethan — who have become particularly adept at installing tips and helping with the cleanup.

This is the step which benefits most from an extra pair of hands and fortunately I can usually get two of my children to help. I do the adhesive injection and part of the cleanup and they install the tips and then place them on the curing racks. Those racks, incidentally, are also custom designed and 3d printed =] You can even make your own with this model file!

Back before COVID nearly all signal sticks were made during a volunteer-driven build night — 10-15 people would come over to my house and I’d feed them pizza while we made antennas. Everyone would leave with an antenna, a few with a door prize, and it was actually pretty fun. That’s been harder in the last few years, so I haven’t done it with more than a few people in quite some time, but the reason it is relevant is that we used to use pizza boxes to stack the antennas on because the box for a large pizza was just about the perfect size. Unfortunately, those were problematic to stack and could not be moved easily without antennas falling off.

With the new racks I can now move a whole stack of antennas out of the way so my loving and amazingly tolerant wife (Sariah, KC7KEI) can put her vehicle back in the garage; they also stack vertically.

The antennas need to cure for 12-24 hours and then they are ready for sale!

Shipping the antennas

The last bit which may be interesting to you is the shipping. My oldest son Caleb (13yo) has been doing the shipping for me lately when time allows around school, but all of the antennas are stored on racks in my office to make it easy to locate.

Why I do this

With all of this, keep in mind that I am a computer software engineer — I’m not a manufacturing engineer and I’m neither an electrical nor an RF/antenna engineer. I honestly did not set out to build this into a company.

Many years ago I saw a need in the ham radio community for better tools around study and administration of ham radio license exams; I set out to try to help with that. For a lot of years it was something that I did purely in my “spare time” (hah, I have 5 kids… “spare time” indeed….) but in 2020 with remote exams I hit a point where I realized I just couldn’t keep this up without dedicating more time to it. Fortunately, by that point Signal Stuff sales had reached a point where I was able to drop to half time at my “day job” and have since that time worked on HamStudy / ExamTools / Signal Stuff part time as well. I still don’t have as much time for software as I’d like, but I hope that if Signal Stuff keeps growing I will eventually be able to do this full time =]

Thus if you place an order with Signal Stuff and I tell you I appreciate the support — that is not just a formulaic response! It really is all of you who support Signal Stuff that allow me to do the things that I really care about. At the same time, if you wonder why I don’t do things like custom antennas or why I don’t spend more time building new designs — it’s because I’d rather build new features into my software.

So there you have it! Feel free to ask questions in the comments; I’m sure I’ve missed things, but like most things I’ve rambled on longer than I intended, so I’ll leave it there for now!

73 all de KD7BBC

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Feb 2022 – Our prices are changing

We have maintained the same price for over 10 years — since long before we opened the web store. Unfortunately, our profit margins have been taking a steady hit:

  • The 1.5mm nitinol wires cost a bit more than the 1.1mm wires did
  • We now have connectors custom made in order to improve quality
  • We’re getting everything in black now so that things look snazzy
  • Material (particularly metal) prices have been slowly but steadily increasing over time
  • Due to issues with COVID we haven’t been able to gather as many suckers volunteers from the local ham radio community to help with manufacturing.
  • Because of the above, I’ve needed to pay another company to build the signal sticks for me, which has a very measurable effect on the margins which actually exceeds the increase we’re making here.

I have been very resistant to increasing prices and have put it off longer than I should — but I’ve had to face facts and admit that it’s past time for a small increase. Our manufacturing costs for the Signal Staff have also increased and so that is getting passed along as well.

Here are the new prices:

  • Black Signal Sticks: increased from $20 to $22
  • Glow in the Dark Signal Sticks: increased from $26.50 to $29
  • Other Signal Stick colors: increased from $23 to $25
  • Signal Stalk 1/4 wave: increased from $32 to $35
  • Signal Staff: increased from $60 to $65
  • All adapters: increased to $5

All bulk discounts remain the same on a percentage basis.

I have already updated the site with the new prices but have put a sale in place to keep things at the previous price for a bit longer but plan to take the sale down in a week (Feb 9, 2022) at which point the new prices will take effect.

As always, thank you all for your continued support! Sales from this site are what allow me to spend so much of my time working on ExamTools and HamStudy, as well as allowing me to support many other endeavors in the ham radio community.

73 de KD7BBC

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2021 Black Friday – Cyber Monday Sale

Another year passed and we’re in November already! Several of you have asked already if we are doing a Black Friday sale — as a policy we don’t give out details of any sales before we announce them. This is a good company policy because aside from other considerations it nicely obscures the fact that I usually decide exactly what we’re doing while we are typing up the announcement. Shhh… don’t tell!

This has been a crazy year and the most notable change is that I’ve had to outsource most antenna manufacturing to a local company here in Utah County instead of building them all myself; I hated to do that for a number of reasons, but I just don’t have time to keep up with building antennas and still write software, and since Signal Stuff exists primarily to enable HamStudy and ExamTools that would kinda defeat the purpose!

Here are some interesting things that have happened this year:

  • Most Signal Sticks were built by a local company instead of by myself (Richard, KD7BBC) and local volunteers
  • We have switched to black connectors on most Signal Sticks and all adapters
  • We have introduced a new Half-Wave super-elastic signal stalk
  • HamStudy now has Spanish translations of the question pools (but the software hasn’t been updated to fully use them yet, sadly. You can still study them if you know the URL)
  • ExamTools, our license exam administration software, was involved in over 30% of the exams administered in the last 12 months! Those exams were easier to administer, more random (no reuse), and generally resulted in people getting their callsigns much more quickly! About 80% of those were remote and the other 20% were in-person.
  • Signal Stuff hired someone to manage shipping — but sadly life changes on the part of the employee have resulted in shipping returning to my basement.
The Signal Stuff Super-Soporific Shipping Station

Here are some things that are still coming up:

  • Sometime soon we plan to have a rubber cover on the outside of the BNC connectors which will hide the notches and just generally look nice.
  • We are working to get Signal Stalk wires which will handle lower temperatures
  • More ExamTools features are being added all the time, with a new registration process and better team management features being high on the list
  • I am experimenting with using Machine Learning and Artificial Intelligence to provide more effective ways to analyze the question pools and study effectively — nothing specific to promise yet, but there are a lot of possibilities.

This is all quite a bit for a single person to do — even with all the help various people give me — so I appreciate the support of all of my customers!

The sale

Okay, this is what you’ve really been waiting for. Thanks for letting me ramble! Sadly I can’t discount quite as much as I have in some past years — material prices are increasing and I’m no longer building things myself. In fact, we will almost certainly be increasing prices in early 2022, so this may be the cheapest you’ll find our products from this time forward! That said, I hope you’ll still find it helpful =]

Our sale will start on Friday, Nov 26, 2021 and last through Monday, Nov 29, 2021, with the following discounts:

PLEASE NOTE: Orders placed before the sale starts or after it ends will not get the discounts; if you didn’t read the dates, we’re very sorry but are still happy to sell you items at regular price.

73!

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2019 Black Friday / Cyber Monday sale

This sale will start on Nov 29, 2019 at 12:00 am MST and run through midnight on Dec 2, 2019.

We have for you this year:

All percentages have been rounded to 4 decimal places for your bargain-hunting convenience!

Also note that the HamStudy.org mobile app will be on sale for $1.99 (50% off) for the same duration! All sales at signalstuff.com support hamstudy.org development and related projects.

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2018 Black Friday sale – all antennas 25% off

From Friday, Nov 23 through Monday, Nov 26, 2018, Signal Stuff will be running a Black Friday sale with all antennas 25% off!

For those of you who have participated in previous years sales, you may not know that these are different (better!) antennas than we have sold in previous years; the wire thickness on our dual band model has been increased by 36% but the flexibility remains! Buy one today! (or, well, during the sale, we suppose)

You know you want one. All the cool hams have one.

All antenna sales support development and advertising of HamStudy.org and related products. Order one here.

More information:

 

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2017 Black Friday sale – all antennas 25% off

From Friday, Nov 24 through Monday, Nov 27, 2017, Signal Stuff will be running a Black Friday sale with all antennas 25% off!

All antenna sales support development and advertising of HamStudy.org and related products. Order one here.

More information:

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Happy World Amateur Radio day!

In honor of this day we are offering free shipping on all orders to anywhere from today (April 18) through Friday, April 21, 2017.

Free shipping valid for both T-Shirts and Antennas.

73 to all!

Update 4/19/2017: It has come to our attention that the free shipping was not correctly configured on the online store — those who placed orders anyway have been refunded the shipping cost and we sincerely apologize to anyone who was affected. The problem should be corrected now.

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Choosing the correct antenna connector for your radio

It seems we have not so far done a very good job of helping people figure out which connector is which, so this is a handy guide to help you figure out which antenna connector you need!

BNC

BNC connectors are common on older radios, often referred to as “bricks”.  They are also found on some newer radios such as the Icom V80. They are a larger connector, but due to the handy “twist and lock” mechanism they are very quick to put on and take off. Some people get adapters for their other radios so that all their radios can use BNC, primarily so that they can easily change between the connector types.

SMA (and how to determine polarity)

Before going over the specifics of SMA-F and SMA-M, note that the polarity is determined by the pin — the connector with a pin is male, the one with a socket is female. This causes a lot of confusion with people who figure the one with threads on the outside would be male, but that one has a socket and is SMA-Female.

SMA-F

SMA-Female connectors were very rarely seen on antennas until the last few years (2014 or so) when many Chinese manufacturers began manufacturing inexpensive radios capable of operating on amateur radio frequencies.  There are a lot of debates as to how good those radios are but most of them require antennas with an SMA-Female connector. There are also some Motorola and Kenwood radios that we know of which require SMA-F antennas, and there may be others that we are unaware of.

It is worth noting that this is not the same connector as a Reverse Polarity SMA, often abbreviated RP-SMA; that has the pin and socket switched from standard and will not fit your radio.  We’ve often seen these called “Reverse SMA” which is semi-accurate since historically most ham radios with an SMA antenna required SMA-Male on the antenna, but it is far too easily confused with RP-SMA and we recommend strongly against using the terminology.

A radio with an SMA-Male connector on it requires a SMA-Female antenna.

SMA-M

SMA-Male connectors are needed by most radios produced by the more “traditional” Amateur Radio manufacturers; nearly all Icom and Yaesu handhelds require an antenna with a SMA-Male connector on it, as do many other brands.

A radio with an SMA-Female connector on it requires a SMA-Male antenna.

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What kind of gain do the Signal Sticks have?

Questions about antenna gain

Probably the question I get asked most is “what kind of gain do the signal sticks have”, and “why don’t you list gain on the site?”  I have answered many people individually, but it comes up often enough that I figured I should probably write up an explanation.

First and foremost, the reason I don’t list the gain of the antenna is that I don’t like to lie to people. I consider it dishonest to give a number which can’t be proven in actual use. Here is the problem with “gain”: gain is a relative term. Literally.  Gain is defined as “increase the amount or rate of (something, typically weight or speed)” — in this case, it would be an increase in output, signal strength, etc.  Here is the issue, though: it has to be relative to something.

When you transmit, you put out a certain amount of power — if it’s a handheld, that might be 5 watts.  If you have an “ideal antenna” then those 5 watts will go out from the radio and nothing will be reflected back to the radio (in a simplified way, this is what SWR is: how much power was radiated vs reflected). However, if you had a theoretically ideal antenna you could have another theoretically ideal antenna which outperformed it in certain cases.  This is because there are actually two things to worry about: 1) the power of the radiated signal, and 2) the direction of the radiated signal.

Some antennas will tell you that they are 3dB gain — this means they will have twice the signal strength of some other antenna. If you see 3dB then you should find out what that is in relationship to.  I can confidently tell you that you should get at least 15dB gain using my antennas…. compared to using a dummy load.

Finally, a “rubber duck” antenna is able to be short because it makes up for it’s short length by adding a “load” to the antenna — typically a coil at the base which loses some energy to heat in exchange for making the rest of the antenna resonant at the frequency you need.  It also changes the radiation pattern, though; in general, only a very very poorly designed “whip” antenna would fail to outperform the rubber duck, but remember that radiation pattern!  In some odd cases I’ve seen it happen, and in a car when the “whip” might have to be bent over the duck will likely work better.

So stop yakking and answer the question already!

Anyway, the long and the short of it is that it’s impossible to tell for sure what the “gain” of an antenna is without doing a lot of careful measurement under different circumstances with very expensive equipment — equipment that I don’t have.  I can’t calculate the “gain” relative to your stock “rubber duck” antenna because I don’t know the exact characteristics of that antenna.  Added to this is the fact that a typical handheld antenna is actually just half of a dipole, and it doesn’t tend to hold still or remain constant relative to things near by that might affect the performance of the antenna — things like cars, houses, trees, fences, other people, your arm, etc.

The dirty truth is that even SWR readings on a handheld antenna may vary as much as 1:1-5:1 depending on what is near, where the handheld sits, how the antenna is mounted, and any number of other factors.  (Yes, I’ve measured that). When companies say that their handheld antenna gets 1.5:1 VSWR they are telling you that they managed to find some setup where they could measure that, not that you should actually expect that performance.  In my experience, most handheld antennas are actually operating at more like 3:1.

Our antennas work very well — they should work a lot better than the stock antenna on your handheld.  If we trust gain figures from other similar commercial antennas we might guess that these are approximately 2dB on 2m, probably 2dB to 3dB compared to an isotropic antenna on 70cm.  We could further deduce that these should be about +6dB compared to “typical stock HT antennas”… and just think, with that and $5 you can get a happy meal at McDonalds!

The one thing to note is that some other antennas have a matching section in the base that turns the 70cm function of the antenna into a 5/8 wave. Signal Sticks are 3/4 wave on 70cm, which will tend to only be a little better than a really well made rubber duck.

 

I hope that answers some questions!

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Using 3d printing to improve the Super-Elastic Signal Stick

One challenge with a project like these antennas is that we are constantly looking for ways to improve on our previous designs. The reason this is a challenge is that often when we develop an improvement which has significant advantages it also changes the appearance of the antenna, which both creates the possibility that people will not like the change and creates a transitory period where people expect the product to remain constant but we have some stock of the old and some of the new.

That said, we’ve been experimenting with a 3d printer and have started producing covers for the antenna and anti-eye-pokers (that’s a highly technical term) for the tips. Here are some pictures of what the new antennas look like:

Advantages

There are several key reasons that we have decided to adopt this approach:

  • Ham Radio antennas + 3d Printers.  Duh.
  • The glue caps (connector covers) are custom designed to both improve your grip on the antenna connector and to hold the epoxy in exactly the place where it is needed, thus these are more structurally sound than the previous version.
  • With these connectors we don’t need the rubber coating and the epoxy is much easier (and more reliable) to apply.
  • The new tips require just a little easily applied glue and are consistent.
  • There are literally dozens if not hundreds of colors and textures of material we could make the connectors with.
  • In summary, the new method:
    • Is awesome
    • Is faster to build
    • Is more reliable
    • Is more consistent
    • Allows more customization

Current colors

We’ve just about got the process to where we can “mass produce” (about 30 at a time) the caps and tips, so we’ve started stocking up.  What we haven’t decided is which colors to use.  Here is what we have right now:

Cap kit

The colors are:

  • Black
    • Note that we don’t like black tips, so these will have other colors for the tips.
    • The reason we don’t like black tips is that they are hard to see, so we keep poking our eyes out and we’re running short on spare eyes.
  • Super-bright glow in the dark
  • White
  • Brown / wood colored
  • Translucent royal blue
  • Green
  • Light blue / glow in the dark (not super bright)
  • Red
  • Pink (none printed currently, but we have it)

We have ordered some more filaments and hope to add to this:

  • Solid blue
  • Yellow
  • Purple

As you can see, there are a lot of options; we will probably make a bit of everything and see what people like, but it’s hard to have any guarantee that anything will be in stock with so many options.

Which colors should we keep?

Leave a comment please and let us know what colors you think should be “standard”?  Would you pay extra (probably $5 or $10) to have a custom antenna made with a specific color?  What do you think of the change?