Homebrew 1/2 Wavelength 2m J-Pole Antenna Build – Part 1 of 2

Building my +5 Staff of Summoning

My Nagoya whip apparently does not cut it with my Baofeng UV-5R. I’m not even sure I’m hitting the repeater, though it’s on a mountain that I can see across the river. I have no elmer to really help me figure it out.

Plus I bought the cheap radio all the more experienced hams told me not to. The Baofeng. One of the “non-compliant Chinese” radios, which a Toronto area radio shop told me they do not carry any accessories for. So many sources told me not to buy this, but I effectively tuned them out. And now I’m not able to tune anybody in to talk.

Okay, I got lost in my own metaphor there. I can hear others talking, but all my attempts to raise somebody, whether on simplex, repeater or on a net check-in have failed. I’m shy, but I’ve put myself out there again and again with no response (okay, except once in a dream, but that’s another story…).

I’m not ready to plop down money on a new transceiver though. And WI5HER claims that it’s “all about the antenna”. Don’t get me wrong, other people seem to have adequate success with their Baofengs. May depend on environment and proximity and density of other users. But where I’m trying to ‘work’ the airwaves, it’s not doing it with the little Nagoya (which is already bigger than the rubber duck it comes with).

So one of the major next steps that is affordable for people in my situation: you have a Baofeng and it’s not seemingly strong enough to reach other people, is to buy or build a J-Pole antenna for 2m.

If you’re not in the club already, two meters is the wave-length of the frequency band we know as 144-148 mHz FM. In the commercial radio spectrum in the US and Canada at least we listen between around 80-108 mHz FM. We usually call that just like 100.3 FM, but the true measurement is megahertz, or as they used to call it back in like the 50s and before (I don’t know when it changed tbh) “megacycles.” 1 hertz is one cycle per second. 1 megahertz is one million times that. Whatever that even means. Here’s a good diagram to help you sort it out in your head.

Anyway the model I followed was basically this guy:

And I even emailed him with questions and he was kind enough to answer (though someone else later gave a reason to do something different).

The measurements I used were based off this j pole calculator.

Best technical explanation I’ve seen of what’s happening (without being too dense) is this video:

I like that there is kind of a trombone quality about these antennas.

https://i1.wp.com/www.kanstul.com/wp-content/uploads/2017/04/TROMBONE-1606.jpg?w=700

I don’t think it’s accidental if we break both these devices down to what they’re doing: enabling the user to transmit a signal at a particular wavelength. One in audio (Hz) and one in radio (mHz). You can explore these feelings more on Wikipedia’s trombone page if you’re so inclined.

Also check out the J-Pole Antenna site. He has a guide for especially Baofengers about using external antennas on your radio, the why and more importantly the how. The guy’s in the US and makes and ships finished versions of what I’ve built below of much higher quality than what I will embark herein to show you now. I submit with humility, knowing the quality of my soldering is quite “shitty”, but this is my first time working with these materials (copper, flux, solder) and these tools really – mainly a blowtorch used in this way.

Best way to get good at something is to experiment, iterate, ask questions, try it out. Then you can do it better later. Sometimes you can succeed on a first try though too.

Jury’s still out on that for me, as I’m awaiting my coaxial cable which will let me mount and link the antenna to the radio.

This is after completing the cutting and soldering of the copper 1/2″ pipe to the measurements on the j-pole calculator.

I never cut copper pipe before. I bought a little $5 pipe cutter, which worked but crappily. This video was useful for general principle:

I also experienced a bug in my process because I bought two wrong parts: over-sized end caps, and an elbow which was 1/2″ on one end, but not on the other. So I bought a straight coupler and used that to join the small end of the elbow to the short arm (1/4 wavelength). There was no issue with that–the two arms are straight and parallel.

 

 

 

I tried to rotate this image, but oh well. This is the copper tubing attached with u-bolts to a stick of wood I will use as a mast and attach to the outer peak of my shed. It’s definitely starting to look like some kind of wizard LARP staff, which I really like.

Maybe I will get a costume to go with it.

https://i0.wp.com/images-na.ssl-images-amazon.com/images/I/41Vryv3yTUL._SL500_.jpg?w=700&ssl=1

Or maybe I can reserve that for when I actually get good at this.

Here is my electrical connection. I bought the SO-239 connector from Durham Radio, outside Toronto (online). Unlike the radio store that told me they don’t deal with my ‘non-compliant’ Chinese radio, Durham actually – you know – sold me radio parts. Go figure!

[Insider tip: you didn’t hear it from me, but they *might* even sell you an Android TV box, which is sketchy af but I like it! Netflix Canada subscribers, you feel my pain!]

Yes, I know my welds are ugly af, but again, first time so cut me some slack. They are sealed, which is mainly what’s important to me rn. On the feedpoint connection, I used electrical solder which I got from the hardware store rather than the plumbing solder I used everywhere else.

Oh, if you don’t know how to solder onto copper, you should take a look at least at this video. It’s really not complicated:

But I guess you can’t pull it off with just a soldering iron, cause you need to actually get the copper really hot (and apply flux first) or else your solder won’t ever really bond. I know because I tried to connect the stripped piece of copper wire I picked up after an electrician did a small wiring job at our house to the back of the SO-239 aka UHF female jack.

Anyway so I did eventually use the torch on it and that worked.

But there’s a pretty big “gotcha” here in this process, because it’s highly likely that you will melt the plastic inner on the UHF female. You can sorta see it poorly in the photo above, the white part is partially melted.

Once I get my coax, I will see how well the PL-259 seats into that. Worst case scenario (I hope) is I heat up a knife and cut out the melt that interferes – if any.

If I had it to do all over again, I would get a smaller or hand-held or ‘micro’ torch and use something which I could more easily control. I already had one like this, a sort of fat big propane canister with a simple control at top. It’s fine for general use, but for a controlled application of heat like this, something smaller would definitely be in order.

Oh well, I will take my lumps as part of the learning process.

Now, in the J-Pole build video above, he uses a flat copper plate to connect his UHF female to the copper pipe. It was non-obvious to me IRL where/how I could acquire such a flat piece of copper.

So what I did ultimately was flatten down one of the too-big copper end caps I had bought with a hammer and very small anvil that I have. Then I used a corded drill, a lot of patience and a little swearing to drill and bore out larger and larger an adequately sized hole to pass the UHF female jack through and connect the nut on it.

I know my results are crappy looking, but I’m proud regardless for a first try. You always encounter problems in building something totally new with new materials and tools, and it’s all about how you improvise in the moment to achieve at least an approximation of your desired end-goal.

As far as I can tell, this will probably do the job. I did a decent job of staying in line with the measurements the J-Pole calculator gave me. I tuned mine for 146 mHz which is right in the middle of the 2m band. Unfortunately, I don’t yet have an SWR meter – though I found that Durham sells an MFJ (MJF?) that works on 2m for around $60 so I will probably pick that up one day. It’s too expensive to buy into all this radio equipment at once before I even know what I’m doing.

A hobby is all about developing an interest into a mild side-obsession. That takes both time and repeated effort and can’t be just bought into all at once.

I would guess that with everything (excluding the cost of tools, coax and the SMA female to UHF female jumper I had to buy for the Baofeng), the J-Pole antenna build I did probably cost me around $20-25, including the mounting hardware. I didn’t keep exact track.

I ordered about 35 ft of RG58 coax, even though I saw some people say RG8U would be better. I honestly don’t know the difference yet, so this is the price of learning. Maybe I make an imperfect prototype. Worse things could happen. Like doing nothing or giving up completely. Cost me about $35 plus shipping.

SMA female to UHF female from Durham Radio outside Toronto, Canada cost me just under $20 plus shipping, but now I have a radio store that will allow me to indulge my cheap Chinese technology desires – even to my own detriment.

But as I see it, how could a learning experience like this be bad?

Unless, once I get it all mounted, wired and connected up people still can’t hear me.

Then we’ll have a problem.

Even if that happens though, I’ll probably still be left with a perfectly serviceable 2m antenna which I can use with a better radio once I finally decide to throw my Baofeng out the window.

Post script:

For every trash-talking ham out there who will tell you not to buy a Baofeng, most of them are talking from experience because they almost all have one. So take that for whatever it’s worth. In technology, ubiquity counts for a hell of a lot. So if you feel compelled to buy one, don’t let someone stop you if it’s your path to learning more.

Interstellar Messages

Call me a late-bloomer I guess, but here I am in my 36th year just now finally getting around to reading Carl Sagan’s masterpiece, “Cosmos”, having not seen the show of the same name and having, so far, spent an insignificant amount of time trying to truly understand what is going on out there in that deep space place.

The book is great, naturally. One thing I did not expect to find is just how much radio related technology gets stirred into the conversation. Maybe it’s one of those things where if you start to focus and hone in on some concept in your daily life, it starts to appear ‘everyone’ in a way that feels like eery coincidence…

Anyway, this passage was wonderful to ponder on…

“On another planet, with a different sequence of random processes to make hereditary diversity and a different environment to select particular combinations of genes, the chances of finding beings who are physically very similar to us is, I believe, near zero. The chances of finding another form of intelligence is not. Their brains may well have evolved from the inside out. They may have switching elements analogous to our neurons. But the neurons may be very different; perhaps superconductors that work at very low temperatures rather than organic devices that work at room temperature, in which case their speed of thought will be 10times faster than ours. Or perhaps the equivalent of neurons elsewhere would not be in direct physical contact but in radio communication so that a single intelligent being could be distributed among many different organisms, or even many different planets, each with a part of the intelligence of the whole, each contributing by radio to an intelligence much greater than itself” – Carl Sagan, Cosmos 

There’s a bunch of stuff about radio astronomy as well that I would love to learn more about. I’m wanting to just try it, even with very low power – just beaming messages out directly into space and waiting to see if “anything happens”.

On a grander scale though, there are things like this Arecibo message:

The Arecibo message is a 1974 interstellar radio message carrying basic information about humanity and Earth sent to globular star cluster M13 in the hope that extraterrestrial intelligence might receive and decipher it. The message was broadcast into space a single time via frequency modulated radio waves at a ceremony to mark the remodeling of the Arecibo radio telescope in Puerto Rico on 16 November 1974.[1] The message was aimed at the current location of M13 some 25,000 light years away because M13 was a large and close collection of stars that was available in the sky at the time and place of the ceremony.[2] The message consisted of 1,679 binary digits, approximately 210 bytes, transmitted at a frequency of 2,380 MHz and modulated by shifting the frequency by 10 Hz, with a power of 1,000 kW. The “ones” and “zeros” were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast was less than three minutes.[1][3]

Listen to the message here:

Close Encounters With The RTL-SDR

Standing on some mounds in the back yard, laptop in one arm, antenna pointed to the skies. WI5HER, Port Townsend, 2017

My RTL-SDR came in the mail a couple weeks ago. It’s a little $20 USB dongle with a long wire that connects to an antenna. And when I say antenna, I mean THIS is an antenna.

When unfolded, it’s almost as tall as a grown human and just ridiculously large enough to make your family or anyone in your immediate proximity cringe in embarrassment for your own sake.

Anyway, I was out on the Olympic Peninsula and after the fam had all settled to bed I went out on the back porch with my laptop and SDR gear and start scanning the frequencies. For less than the cost of taking a date to the movies, the rtl-sdr allows you to flip around the airwaves between 500 kHz to 1.7 GHz and visually see a ‘waterfall’ of incoming radio frequency traffic.

A typical waterfall

I started by first finding the local FM radio stations and from there chronicling and recording a whole slew of beeps and bloops all over the dial. I pushed the ear buds deeper into my noggin and smiled with delight!

Then, up around the 450 Mhz zone, I heard a voice descend from the æther.

At this point, I started to really flip out – I hadn’t expected to hear anyone talking in this range, and especially not someone seemingly reading what sounded like absurd poetry.

It was too good to be true. Was this a pirate broadcast? A “messenger” ?

Turns out, there’s a much more reasonable explanation. This is not poetry, per se, but something called the ‘Harvard Sentences‘.

A collection of sample phrases that are used for standardized testing of Voice over IP, cellular, and other telephone systems. They are phonetically balanced sentences that use specific phonemes at the same frequency they appear in English.

My understanding is that certain companies may play these sentences on a loop and then drive around and judge signal strength based on how well they can understand the words being spoken.

The sentences are strange, sometimes profound. I think they would make for some amazing “performance art” that would make Yoko Ono proud. Or a beautiful ritualized “spell” script.

Take for instance this list…  can’t you imagine trying to “accomplish” each of these steps in order to unlock some sort of otherworldly “achievement” ?

  1. The boy was there when the sun rose.

  2. A rod is used to catch pink salmon.

  3. The source of the huge river is the clear spring.

  4. Kick the ball straight and follow through.

  5. Help the woman get back to her feet.

  6. A pot of tea helps to pass the evening.

  7. Smoky fires lack flame and heat.

  8. The soft cushion broke the man’s fall.

  9. The salt breeze came across from the sea.

  10. The girl at the booth sold fifty bonds.

A full list can be found here.

 

Taking your amateur radio exam at an Industry Canada office

I find these questions in the Basic Qualification exam to be really ridiculous:

There are a number of questions about this:

  • That the fee at an Industry Canada office for the exam is $20
  • That if you use an accredited volunteer exam, the fee is “negotiable”
  • And that the certificate itself is free.

First off, I think this is really weird and pointless to include in an official test. Like, if I’m taking the test somewhere, can’t the person giving me the test just tell me how much it costs? Or you know, like just post it on the website. Why try to trick me and make me memorize all this?

Anyway, I’m nearing the time to take my exam, and I’ve already found a qualified examiner. I think it’s slightly weird, personally, that I have to arrange all this myself. Do I have to go to the house of a stranger for this? Why can’t there just be an agreed-on fee for the test? What if I don’t want to negotiate?

So I wrote to Industry Canada (now called ISED, Innovation, Science & Economic Development) to find out about taking the test at an official office. Based on their responses to me, this seems really frowned upon, despite the fact that the test itself TELLS ME it’s an option (a right?). They simply told me the URL to look up examiners near me. When I questioned whether it was even an option to take it at the office anymore, they responded:

“I can pass along your request to the Ottawa office.  Please note, these appointments are scheduled on a case by case basis. In addition, there is a $20 administrative fee, should you wish to move forward with having the exam done at an Innovation, Science and Economic Development office in Ottawa.

An accredited examiner will be more readily available, and not all examiners request a nominal feel to cover their administrative costs.”

If you don’t know Canadian geography, Ottawa is a 5+ hour drive from where I live. I’m assuming they don’t mean that I would have to drive out to Ottawa to take a $20 test which, as far as I can tell, is supposed to be readily available to me. What does this mean that scheduling a test is done on a “case by case basis?” Is it possible my request might be refused by the government?

Perhaps this is just a case of a mid-level functionary who just wants to get me out of their hair. But given the overall difficulty of even the Basic qualification in Canada (versus the simplicity of the Technician class exam in the US), it almost feels like it’s intentional, that they are actively trying to dissuade people from getting involved with this technology. Perhaps there is an unexpressed desire to kill off the hobby and re-allocate the bandwidth to paid industrial applications.

I don’t know, but so far this is sadly par for the course up here. Canada, if it really wants to innovate, ought to set up a novice/technician license option and make it easier for new users to get on the air.

Q Codes: QNL

The QN Signals are Morse code operating signals that were introduced for Amateur radio net operation in 1939 on the Michigan QMN Net to lighten the burdens of net control operators.

Source

Same source:

Although these codes are within the Aeronautical Code signals range (QAA–QNZ) and thus conflict with official international Q signals beginning with QN, the ARRL informally queried FCC’s legal branch about the conflict. The opinion then of the FCC was that “no difficulty was forseen as long as we continued to use them only in amateur nets.”

I’ve never used these codes. I’ve never transmitted on the air. I have an American Technician class amateur radio license and am almost done studying for Canadian Basic qualification.

On Wikipedia source, linked above, there is a section: ARRL QN Signals For CW Net Use.

QNL as a CW abbreviation is listed as:

A notice to a named station that the frequency that the station is transmitting on is lower than the Net’s nominal frequency. c.f. QNH.

QNH, meanwhile:

A notice to a named station that the frequency that the station is transmitting on is higher than the Net’s nominal frequency. c.f. QNL.

H seems to be representing High and L, Low.

I’ve been trying to decipher how the Q codes overall work. Here’s a good operational list of Q codes. QN subset not listed there. Only QR, QS and QT.

I’m assuming three letter codes are a function of telegraphy codes and have seen docs online placing the origin and popularity of various forms of telegraphy codes between (approx.) 1880’s – 1920’s.

It seems like there are just so many different overlapping sets of codes, decisions, agreements, organizing bodies, etc. It’s mind-boggling to try and untangle all of it.

I’ve only caught in the wild locally an amateur radio net (once) using a repeater I think about 2 hours drive away. I’m not sure how to find their schedules or frequencies. I am scanning with SDR, learning on my own. It’s like the internet but it’s not. It’s its own thing, for sure.

Excerpt from an ARRL document on QN Signs:

I’d like to learn more about nets. And untangle all these codes and abbreviations. It’s a compelling puzzle I’m engaging in for the sheer puzzle of it all.

Like this, what does it all mean, the Aeronautical Codes:

First defined in ICAO publication “Doc 6100-COM/504/1” in 1948 and in “ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PAN a S-ABC)” [Doc8400-4] (4th edition 1989), the majority of the Q codes have slipped out of common use; for example today reports such as QAU (“I am about to jettison fuel”) and QAZ (“I am flying in a storm”) would be voice or computerized transmissions.

Computerized transmissions.

Q Codes page on Wikipedia.

“Q” has no official meaning, but it is sometimes assigned with a word with mnemonic value, such as “Queen’s” (e.g. QFE = Queen’s Field Elevation), “Query”, “Question”, or “reQuest”.

I like this idea that “Q has no official meaning” but that it’s probably a question, query, inquiry or request of some kind.

QN is probably kind of like “Query Net” then I gues… though I haven’t found any document confirmation that in Q codes, N = Net. (Labeling as Assumption for now)

Quasi-natural language?

QNL is used outside of radio to mean, occasionally, Quasi-natural language. References seem to abound for natural language programming, bots, conversational UI, etc. In some sense, that starts to feel similar to procedural words or prowords in radio:

Procedure words or prowords are words or phrases limited to radio telephone procedure used to facilitate communication by conveying information in a condensed standard verbal format.

I imagine QNL as a kind of clipped procedural language subset (superset?) used for specific kinds of transactional communication. Like the Q codes as a whole themselves, or radio prowords.

Something something, performative speech acts.

Wikipedia, Performativity:

… the capacity of speech and communication not simply to communicate but rather to act or consummate an action, or to construct and perform an identity. A common example is the act of saying “I pronounce you man and wife” by a licensed minister before two people who are prepared to wed (or “I do” by one of those people upon being asked whether they take their partner in marriage). An umpire calling a strike, a judge pronouncing a verdict, or a union boss declaring a strike are all examples of performative speech.

Beginning with Software Defined Radio

Observation and exploration with gqrx for Mac

I bought a Nooelec NESDR Smart, which is a USB dongle that allow you to connect an antenna to your computer so you can listen to RF (radio frequency) signals over the air.

It’s really cool but also daunting for new users without much experience or understanding of RF technology. I’m on Mac, so I finally settled on gqrx as my app to interface with the SDR dongle. The main app view looks like this:

The above screenshot appears to depict a broadcast FM station at 96.185 mHz.

Tuning into broadcast FM stations is the easy part of tinkering with SDR, whatever app you’re using. It’s all the stuff outside of that where it gets complicated.

Check, for example, this 2014 Radio Spectrum Allocations chart for Canada:

Depending on what band you’re looking at, the whole thing gets pretty complicated — and fast.

I’ve used a little bit as a guide the RadioReference site, Canada section, to help me figure out some broad strokes of what areas to go hunting for what kinds of signals (ie, what frequencies in mHz to try monitoring). Things like local police, for example, though I haven’t had huge success with that. But as a result of my experiments, I’ve come up with a sort of generalized “listening protocol” as I work my way blindly through the mass of RF frequencies out there.

Observation

Since I only rarely know what a signal is, I’ve started simply taking notes on what I observe, and in some cases recording samples of signals I hear.

Generally, what I will do is choose a specific frequency band that I’ve heard works on SDR (you can’t get all bands on an unmodified SDR unit), like I read that 400–500 mHz is supposed to contain walkie-talkie traffic. Now, it’s tough when you read something like that online, as the same band might be allocated differently depending on the country you live in. I don’t even know if that’s valid for Canada, but I gave it a shot and starting at 400 mHz incremented 1 mHz at a time upwards and simply wrote down what I observed in the app.

For example, at 406.536, exactly at the stroke of 5pm, I heard a man’s voice in French say “dix-sept heure” (five o’clock).

At 406.588 400 mhz (NFM — narrow-band FM), I recorded the following signal:

406.588 400 mHz Quebec, 26 March 2017

Listen to 406.588 400 mHz Quebec, 26 March 2017 | Clyp is the easiest way to record, upload and share audio. No account required.

Now, I don’t actually know what this signal is, nor “what it means” in the grand scheme of things. I simply noted it, described it, and recorded it. On a piano, I also tested until I found the two initial notes or tones (e.g., frequencies), which begin the segment, F → C (F3 → C3, I think). [Tone generator, to test and determine freq.]

Again, I have almost no idea of what the above frequency is. Sounds like “data” of some kind, but I’m not advanced enough to know what exactly. Or even to begin looking. However, I believe there is great utility in using this kind of observational method and careful listening to uncover patterns in just about *any* domain of knowledge, but especially in RF. I figure, with enough practice and research, I’ll be able to hear a signal, check the band its on, and eventually with a certain degree of accuracy figure out what’s going on.

It may seem like a kind of “why bother” activity, but I’ve set myself to learn all about RF technology, and so far it’s really fun for me. It’s a way to participate in a sort of “secret internet” of signals that surround us every day without having to go through my wifi router, my internet service provider, etc. Without being exposed to ads and trolls and fake news and bad news. To just experience the raw signals and hopefully, eventually, to understand them.