QRP

All posts tagged QRP

On September 5, 1977 NASA launched the Voyager 1 space probe from Cape Canaveral to study the outer Solar System. The little guy just kept on going into interstellar space, still transmitting out of its twelve foot dish antenna, blissfully unaware that QRP doesn’t work. Well, Voyager cheated a little, I do too sometimes, by using twenty three Watts of power, still almost 538 million miles per Watt. Imagine waiting more than thirty seven and a half hour to get a reply to your CQ! Sure, Earth has big ears, but let’s not tarnish NASA’s golden record; pun intended.

Back down to Earth, are we? Some amateurs use levels of power that if not your head, will make your electricity meter spin. How much power do we need? The FCC says as little as possible to make a decent contact. Some play with micro-Watts and get through; millions of miles per Watt. Transceiver manufacturers seem to have settled on one hundred Watts, a number most likely based on marketing and economical factors rather than real life applications. One hundred is a nice round number. I am a big fan of QRP, or rather, ultra-portable radios, usually five to ten Watts. My friend Ray and I used to experiment with reduced power down to one hundred milliwatts over more than eight hundred miles; CW of course. Why signal with a flashlight when you can use a laser pointer? I was making regular contacts to Eastern Europe from Florida using from one to five Watts to about six thousand miles. Power is expensive, in dollars, Amperes and kilograms.

The military figured it out long ago. They deal with life-and-death communications from the field, portable man-pack operations in HF, which is still in use, just not the only option anymore. My RT-320 outputs about twenty five Watts, as do most military portable transceivers.

Power does help, nobody can deny it. There is however the law of diminishing returns. When the ionosphere isn’t cooperating no amount of power will get through. When it does, you don’t need much to be heard. A good resonant antenna and some knowledge will go a long way. I bet inadequate antennas radiating only a few Watts rather than the hundred coming out of the transceiver are the norm rather than the exception.

I suggest any new Hams to save their money, study antenna designs and spend an afternoon at the hardware store. Amplifiers are mostly used for contests where the goal is not to make contact but crush the competition. Better chase losses, hunt for noise sources, use better aerials and more efficient modes like CW or PSK-31.

I believe the magic numbers are five Watts CW and twenty five Watts SSB. You can go on a nice DXpedition for the price of an amplifier. If someone doesn’t believe how well they hear your five Watts, tell them the story of the little probe that could.

We’re all supposed to get along right? Sharing the same space, in this case amateur radio bands, in an atmosphere of respect and friendship… Until a contest is on. A Ham contest, for those who don’t know about them, is a weird hobby, a bit like train or plane spotting. People get on the air and make as many contacts as possible over a week-end. A contact lasts only a few seconds, just an exchange of call signs, and that’s it. There is no conversation taking place. There is no human interraction, so to speak. If that was all there was to it, it would be fine. People do what they want, it’s none of my business. Until their hobby is infringing on mine that is. Infringing in this case is too light a word. Until it obliterates mine for a whole week-end that is. They do this regularly.

Contesters think absolutely everyone loves contests and participates. So they park themelves on calling frequencies regularly used for low-power operations and call every few seconds for hours-on-end using hundreds of Watts, trampling on every other signal. It’s a contest, a free-for-all Roman arena, and damned be anyone who want to chat with their friends or make new ones using a respectful few Watts of power. They drool over their microphones or Morse key with bloodshot eyes. They need those points to win a new plaque or certificate for their trophy room. If the Ham radio contest was a touring rally, they’d run pedestrians over with their cars.

You would think contest organizers would police, or at least educate their members, but no. Because contest organizers are also contesters. The biggest culprit is the ARRL. Their station, W1AW monopolizes QRP (low-power) calling frequencies for hours with incessant calling using high power, and damned be anybody else. They to this all the time outside contests. How could we expect them to police contests? They even broadcast their Morse code practice daily on multiple bands. While I think that is actually useful, although I wish they used classic books instead of technical articles, it is against the law. But the ARRL is above that. Why should they worry about mere mortal radio operators using little home-built radios not manufactured by their corporate sponsors?

Contesters will also say that non-participants can go the the WARC bands, 30, 17 and 12m. Well, not everyone has those or an antenna to accomodate them. Don’t piss on me and tell me it’s raining. Why don’t we have one contesting band and you guys can all go to it where you won’t bother everybody else? How does that sound? They also say contesting is the Godsent gift to Ham radio. As if amateur radio would collapse without them. I don’t think so. I was also told “if you can’t beat them, join them.” Nope, not going to happen. Just like I wouldn’t sit outside an airport writing down airplane tail numbers all day or go to a cross-dressing furry swinger’s party… Not my cup of tea, although I’d choose the furry party over a Ham contest any day. To me, contests are pointless and weird, and that’s it, so no, I won’t participate, I’d rather watch paint dry.

Bottom line is, when a contest is on, way too often, I might as well go fishing or something, because turning my itty-bitty radio on is as productive as pissing in a violin. The lack of respect is appaling. There isn’t a wide enough stretch of frequency left free of pollution for long enough for me to contact, let alone chat with anyone.

You want to enjoy your contesting hobby? Fine with me. Just don’t keep me out of mine to enjoy yours.

It’s alive! After three hair-pulling days, the radio finally works. I received the box on Thursday night; no time then to start, but I got to it after my daily work session on Friday. Late that night, I had completed the filter board, one of the three circuit boards.

I must here explain what an Elecraft K1 is.. Though it sounds like some fighter plane name, it is a receiver/transmitter (a “transceiver”) which transmits, and receives CW (Continuous Wave) Aka “Morse Code.” It is very small, and covers up to four Ham radio bands. Mine has two, 40 (7Mhz) and 20 meter (14Mhz). The power output is fairly low (7 Watts), but that is sufficient to bounce your signal around the earth.. Imagine seeing a 7 Watts light bulb thousands of miles away! Somehow, it works. CW punches through further than “phone” (voice). The K1 is in a class of radios called “QRP,” meaning low power, usually 5 to 10 Watts. It is only sold as a kit, so if you want one, you must build it, or find a used one.. I chose to build it..

Elecraft K1

Elecraft K1

I don’t understand the fear about winding toroids. I find it very easy and relaxing; it hurts much less than it sounds. All you have to do is count how many times you thread a wire through a ferrite core. How easier can it be? Then, you burn the enamel off the leads with a lighter, clean them up with your snipping tool, and solder.. I was very exited that night about the project. I thought it would be a walk in the park.. Not quite..

The front panel was next. The only difficulty there was soldering the LCD display. Attaching the wires to the ten-turn potentiometer also required some dexterity. About wires.. There are very few in the K1 kit: The potentiometer lead wires, speaker wire, and one coax jumper on the back of the board, that’s it. Everything else is connectors. I like that. Soldering wires is always a pain in the butt.

The RF board was the biggest and longest one to build. It took me from around 10-am on Saturday to about 2:30-am on Sunday to complete it! And it didn’t work! In retrospect, I should have only completed the receiver part that day, leaving the transmitter for Sunday. When tired, your brain plays tricks on you, and you make mistakes. Everything went fine with the receiver. I heard static when I turned the K1 on, no smoke. After tuning the receiver and plugging-in a long wire, I was listening to CW on both bands. I was exhausted, but proceeded with the transmitter side. It was 9-pm already, eleven hours of looking at tiny components, placing and soldering them.. Then came the time to test voltages on the RF board. Nothing on U8! Shit! Excuse my French.. That wasn’t good. I nevertheless plugged-in the filter board to test power output. Nothing.. Followed about an hour of tinkering, swearing, manual-reading, head scratching shenanigans, of which I remember almost nothing (I had been working on it for 15 hours straight). I rewound the bi-filar transformer, reheated solder pads both on the filter and RF boards, zilch! Then I gave up, and decided to complete the build for the heck of it, and call Elecraft in the morning. Yet, after putting the speaker in and closing the box, I tried again. Power on 40m! Not on 20.. Ah.. Back to it (2-am).. I think I transmitted without a dummy load and no antenna a couple times by the way, I was so tired. Anyway, I have no idea what did it, but after countless little troubleshooting steps, and more tuning of the filter board, I finally got output power on both bands. I packed it up and went to bed with a headache and slight twitching..

Elecraft K1 inside

Elecraft K1 inside

Comes Sunday morning, I had a working K1! The only peculiar thing left to investigate is some power fluctuation.. If I set the maximum output to 2 Watts, the watt meter shows 2W at first, but then slowly climbs to 2.8. I am guessing that the final transistor produces more gain as it warms up.. I even produced about 10W tuning the filter board before the output suddenly dropped! Weird.. After tuning the filter board on receive, things are a bit more stable, still with quite a power increase as transmit time increases.. It shouldn’t occur producing CW though, as this was transmitting a continuous tone in tuning mode. We’ll see..

I spent Sunday evening listening to CW outside, with a wire strung horizontally (20ft maybe) about five feet from the ground; the worst possible antenna. Still, it was easy to pick-up signals. I even heard a guy saying he was on a sailboat, and retired three years ago (I have a Morse decoder app on my iPod!).

The Elecraft K1 kit is of very high quality; much better than any other kit I have seen so far (five). Everything fits perfectly, nothing was missing. I even had much needed left-over screws (I spilled them all on the garage floor).. The box looks great, and the way the circuit boards are positioned and fastened is brilliant. I will order the automatic antenna tuner and add it in soon. For now though, I need to finish learning code, then I’ll go for the General Ham license (CW is no longer required). The K1 was the right choice, at the right price. You get a lot for your money. It might not seem so when you buy the kit, but after building it, I find it very affordable.

To anyone contemplating building one, go for it! Build a couple kits first, like a Small-Wonder-Labs Rock-Mite, and a SOTA tuner from qrpkits.com, and you’ll be well on your way. Moreover, you can test the Elecraft receiver with the Rock-Mite! Get 50ft. of wire from Home Depot for the SOTA tuner, and you’ll be all set. Follow the manual EXACTLY. Don’t skip ahead, read every line! Double-check everything. Most importantly, don’t do what I did. That was stupid. Take your time. If you feel tired or stressed, stop, rest, and don’t get back to it until much later. I was very lucky that I didn’t fry anything. Not to mention the stress and lack of sleep.. Not a healthy way to spend a week-end..

In the mean time, like they say over there, “Everything is fine in the best of worlds.” I am a happy, proud builder and owner of an Elecraft K1. The satisfaction of building something that complex with your own hands is priceless..

I decided to build an Elecraft K1. What the hell is that You might ask.. Though you probably guessed it is a radio. I’m on a roll. I know, I know, I just finished building a small one (DC20B) and am waiting for another tiny transceiver called a Rock-Mite. You need to learn to walk before you can run.. Why not buy something already made? It isn’t more expensive.. Well, the Elecraft K1 has an excellent reputation, and it isn’t sold assembled. If you want a new one, you must build it. I am good at that stuff, and do enjoy the process. Still, I could find a working Ham radio on Ebay for the same price; but that would be a used item. Not to mention that the K1 is the cutest little radio (did I just say that?).

There is one peculiar thing about this radio, aside from all it’s qualities, that is, you can’t talk in it.. Morse code only! Also known as “CW” (continuous wave). So I am learning Morse code, and it is far from easy. Why bother? First, a Morse-only transceiver is much simpler and smaller than an SSB (voice) one. It draws less current, which becomes very important when operating on batteries. The K1 will happily work for days on eight AA batteries! For example, a Yaesu FT-817ND draws 450mA on receive. The K1 draws 55mA! More importantly, when propagation conditions are bad, a CW signal will punch through the ether when another mode won’t. In an emergency, being heard might be a life-or-death condition. Even with no cell phone coverage and no satellites overhead, there is a good chance the K1 will be heard somewhere, even thousands of miles away. Yes, thousands of miles directly, on eight AA batteries! What else can do that? It doesn’t mean I won’t take my cell phone or a Spot when hiking far from civilization. However, cell phone coverage is spotty in the North West, and with the Spot, you can’t specify the type of emergency, and can only use it for dire situations. If I need anti-venom after a snake bite, it won’t do me any good to get picked-up by a helicopter if they don’t have the serum with them.. A radio allows you to call for a specific kind of help. Like any other gear, if it is too heavy or too big, you will most likely not take it with you. Light and small is better when you need to carry it on your back.

My plans are to first complete the 20/40m model with no add-ons. Then, I will build the built-in antenna tuner. This option allows you to use a random wire as an antenna without risking frying the transmitter. If you lost your antenna and all you can find is a length of barb wire, the tuner can save your bacon. Just hang it up a tree, press the tuner button, and seconds later, if you’re lucky, you will be having a conversation. I might add a noise blanker later.. One item I decided against is the built-in battery pack. You can’t charge the batteries while they are inside the case, so what’s the point? I heard it is a flimsy add-on anyway. I don’t think I’ll need more than two bands, but time will tell. The antenna I chose is the Par EF-10/20/40 MkII end-fed dipole. Also on my wish list is a solar panel (PowerFilm AA Battery Solar Panel Charger) to charge those AA rechargeable batteries. For EMP protection, I decided to get some TechProtect Faraday bags.

I will document the build and post it. Average build time is about thirty hours, but I am pretty fast with a soldering iron. I will start next week-end (June 9th), stay tuned for the article, and maybe a video. Hopefully by then I will have learned a few more letters of Morse!

How big of a radio, and for how much money can you communicate across thousands of miles? What about something that fits inside a box of Altoids mints for $29? The best part is, nobody can ever cut you off!

Rock-Mite

Rock-Mite PCB


This is the “Rock-Mite” from Small Wonder Labs.
(Google “rock mite” for Altoids-mounted boards!)

Sure, you’ll have to learn morse code… I can’t think of anything that small however that truly can be used as a pocket emergency radio. Add a long wire antenna, a mini tuner, AA batteries, and you are in business. With the “Mity Box,” and connectors, your total cost comes to $70, still a bargain. My RockMite is on it’s way (20m version)!

Another kit I just completed is the DC20B.

DXxxB

DXxxB PCB

You can see that it is a bit more complex than the RockMite. You need to wind transformers by wrapping a certain number of turns across small toroids with very thin wire. The kit also requires tuning. The Rockmite is pre-tuned. Performance is supposed to be better, we will see…

Assembly took a whole afternoon and evening. I had never soldered on a double-sided circuit board, but it turned out to be fairly easy. I just made sure I had a good solder joint on both sides. I started with the smallest components, resistors and diodes, then integrated circuit sockets, capacitors, and transistors, leaving out the final transistor until everything was squared away. To my delight, I heard morse code when I turned it on and attached a long wire! The volume was very faint, hopefully that will change with a tuned dipole up in the air.

There is one little problem remaining. I have also built the frequency counter kit from N3ZI. The oscillator frequency of the DC20B is supposed to be 14,060khz. I get 14,063.2 minimum.

DC20B Frequency off

DC20B Frequency off

Hopefully I will be able to fix the problem. It might be a calibration issue with the frequency counter. Since I do not have an HF Ham radio, I can’t check it. Once I build the RockMite I will have a way to verify the frequency.

 
[warning]DCxxB builders: C36 has a missing trace to ground. Make sure you solder a short piece of wire from the pad closest to the board edge to the ground..[/warning]

Both the DCxxB and Rock-Mite have keyer chips included. That means it can generate Morse code from an Iambic paddle you plug-in. These radios serve the same purpose. For some, there is the challenge of contacting distant stations on very little power (500mw to 1w). Others take them camping, hiking, and on all kinds of adventures. I am of the second type. The RockMite will have it’s place in my bug-out bag as well. Heck, I might build a second one as a backup.

My choice between the two? Rock-Mite; because it requires no tuning and has no toroids to wind. You can easily find help online, along with a list of possible modifications. Both kits have a Yahoo group. The Rock-Mite group though did not at first accept me! Why? Because I don’t yet have a license and call-sign! The DCxxB group had no problem with me joining. It turns out that the groups are owned by the same person.. And I was accepted at last, after complaining. These kits are a great way to get started, and while groups need to be monitored, access shouldn’t be restricted…

Learning Morse Code turns out to be pretty hard for me. Some people have no trouble and wrap it up in a couple weeks. I’ll be lucky to take only three months! My brain isn’t wired that way I guess.. I use an iPod app: AA9PW Ham Morse. It uses the Koch Method, which is supposed to be better. I had to slow down the learning speed from 15wpm to 12wpm, just to be able to write fast enough. I might just try to build the sentences in my head… I don’t think anyone can write that fast; not me anyway.

As to my HAM license(s), I am in no hurry. I read the Technician class book once and never miss more than one questions on the QRZ.com practice exams. So, I took three General class practice exams, just out of curiosity, passed two! Barely, but still… I am reviewing for that class now. I might as well pass both tests at the same time. Maybe I should get the Extra class as well, why not? If not just to see the face of the examiners, asked which license I am testing for, I’ll say “All of them!” and get close to 100%. Listening to HAM conversations, I have to say that what I have heard isn’t that interesting. It is a somewhat weird crowd. Mostly old fat guys (no offense intended). As to public service, in times of relative safety, radios are useless. You don’t need a ham radio to help with a local fund-raising marathon.. Just use cell phones! I laughed when I heard a “Net,” the controller asking “Is there any emergency traffic?” Are you kidding? We call 911 for emergencies! There is also the “contesters,” who won’t give you the time of day and just want a call-sign and “grid number” to add to their collection. How useless is that? Anyway, there are also great things in Ham radio. Groups do take their transceivers atop mountains and in all kinds of remote areas. I like the idea of it being a safety net, some kind of support apparatus. Besides, you don’t stay in shape by sitting in front of a radio all day…

I will post an article on building the RockMite, with a video, when I get the kit (I was told ten days before it ships).

Here is what comes to my mind when talking about any item: “If it can’t carry you, and you can’t carry it, don’t bother.” These two small transceivers certainly get my thumbs up!

Update (May 27th): I think I am going to ditch the DC20B. I have a box for it, and should complete the build, but after that, it’s going away. I can’t get it on frequency, and I am not the only one… The Rock-Mite kit should arrive this week. I can’t wait to build it. Look for the article!

Update (May 30th): Well, I gave it one last try.. Changed C36 to a 100pF, and C29 to 47pF. It worked! Now I get 14,059.72 on transmit. Receive goes from 14,060.16 to 14,060.32, a perfect 600Hz offset. The problem is the receiver, which has no selectivity. I receive Chinese, French and Spanish commercial radio stations, but little, faint CW signals. Maybe the problem comes from the wire I use as an antenna, which isn’t tuned. I will try a tuned dipole during the day and see if I can get clear CW (morse code). I boxed up the DC20B in a nice Hammond cast aluminum box. I made a hole in the cover to tune CT1 and glued a piece of coax outer insulation so that I can’t touch anything with my screwdriver upon insertion.. The box is a little big, but it looks good and as though it would survive being run over by a semi-truck.. I might make another hole for access to CT2 and add an RCA plug for a frequency counter (for tuning).

Update (August 1st): The tuned antenna did the trick. Good selectivity now, and the radio is on frequency. The DC20B gets the thumbs up!

DC20B Boxed

DC20B Boxed

Note the piece of insulation glued on top of CT1.
I wish that damn iPod could focus up-close.
Still waiting for the Rock-Mite.
I am starting to think about an Elecraft K1.