Dave Richards AA7EE

January 28, 2011

Barriers To Sending and Receiving Faster CW

Filed under: Amateur Radio,Ham Radio,QRO — AA7EE @ 10:57 pm
Tags: , ,

I’ve been pretty comfortable with sending and receiving code at about 15 wpm for the best part of a year now.  I write down all my copy as I receive it, and always send with a straight key – the KK1 from American Morse Equipment. This arrangement has worked quite well and when I think back and realize that my first CW QSO (not counting the only half-dozen or so I’ve had since being licensed in 1978) was just 18 months ago I feel quite pleased.  The idea of having any CW QSO at all was foreign to me – the few that I had had before were a struggle to get through. Admittedly many of my QSO’s are cookie cutter ones with the standard exchange of RST, QTH, rig, antenna, power and perhaps a mention of what the weather is like.  We might chat a little bit about something else before signing off. That is all that many CW ops want out of a QSO and to be frank, it’s often all that I want too.

Sometimes when I want to get a little more conversational though, I’m prevented from it by two things. Firstly, you can only transmit so many words to the other operator in a certain amount of time at 15wpm or below. If you try to say too much, it just takes too long and gets boring for both ops. The other barrier is that I haven’t been thinking in code; I consciously hear the sounds and translate them into letters (or occasionally, complete words).  When sending, I go through the mental process of thinking what I want to say and translating it into code before sending it.  I think it’s this mental barrier that is preventing me from sending and receiving more swiftly – well, that and the fact that sometimes I just don’t have that much to say 🙂

This morning I called CQ on 7030 and was excited to receive a call from Don W6JL.  As you know from this previous post, he is well known to me and though I’ve had many opportunities to call him, I haven’t, as I knew he’d probably find copying my max speed of around 15-18wpm tedious at best.  He’s also very comfortable being conversational on the paddle, and I am not, so I just didn’t want to put him through the experience of a QSO with me.

Donald asked me why I was using a straight key, and I replied that I’ve been practicing with the paddle, but it keeps running away with me! I haven’t yet mastered the art of sending “s” instead of “h”, or “b” instead of “6”, for example! I tried sending to him with the paddle, but things got a bit out of hand and I reverted to my comfort zone with the straight key. One important thing that Donald managed to persuade me to do was to throw away the piece of paper I was using to write all my received copy on and start learning to copy CW in my head.

After giving it some thought, I think that the main reason I’m having trouble copying in my head is that at 15wpm or below, I’m not thinking of the code as a series of thoughts and ideas, but as a series of words that I have to string together in my head before I can make sense out of them.  Invariably I find that by the time I’m at the end of a sentence, I’ve forgotten the words that were at the beginning, and so the meaning is lost. If I keep working on my speed, I think that by the time I’m copying at 25wpm+  I’ll naturally be listening to the code as a series of thoughts without having to consciously translate them.

It was a pleasure to QSO with Donald though I’m looking forward to doing so when I can communicate more at his level of speed and fluidity. His station is all home-brew and utilizes a phasing-type high performance direct conversion receiver with a Dan Tayloe-designed front end. He runs full QSK and hasn’t found a commercially-produced rig that gives the performance he gets from his homebrew station.  Although it’s not the most up to date version, you can read about his station and see pictures of it here. Don made an interesting point about transmitter power to me. He uses a 2 element yagi for 40M.  On first reading that sounds impressive, but he pointed out that this gives him just 4dB of forward gain. Now anything that gives you gain is a help of course, but if you want to make your signal easier to copy in the other guy’s receiver, the easiest way to do it is to increase your transmitter power. This pre-supposes that you have already got yourself a decent antenna as high and in the clear as you can manage; it would be a bit silly to run a kilowatt into a random length of wire on the floor of your shack.

Let’s look at power for a minute.  Say that you are running the QRP “full gallon” power of 5W.  If you double your power to 10W, that gives you a 3dB increase in power, or 1/2 an S-point in the other guy’s receiver.  Doubling again to 20W gives you 6dB – a full S-point.  Doubling two more times to 80W gives you 2 full S points. Most commercial transceivers put out 100W when running barefoot (and so does the Elecraft K2 with the 100W option – the object of my current desire.)

OK, so you decide that you want a bit more power.  Double that 80W 2 more times to 320W and you now have a 3 S point advantage over your original 5W. This means that running the full legal limit of 1500W will give you a little more than a 4 S point advantage over the original 5W signal.  4 S points doesn’t sound like much in return for that whopping amplifier you are now running, and when propagation is well in your favor, it probably isn’t but let’s face it, the propagation gods haven’t exactly been smiling on us recently have they? (I know, things have been better, but there’s still room for improvement.)  4 S points means that the guy who would have given up trying to copy your 219 signal now finds that you are 559 – a big difference.

Goshdarnit – how did I go from thinking I never wanted to run more than 5 watts to dreaming of how nice it would be to have, say, a 500 watt amp?

Anyway, the call from W6JL this morning and the resulting QSO gave me the kick in the pants that I need to get more serious about upping my CW speed and also gave me food for thought about the eventual possibility of upping the power here at AA7EE.

January 25, 2011

Beta Testing A New CW Transceiver

I’ve been passing on news in this blog about Jason NT7S’ upcoming QRP transceiver kit, which he initially referred to as “Project X” before revealing the name of the series of transceivers as the CC series, and the first model for 40M, the CC-40. He also told us that his new open-source amateur radio company will be called etherkit.

I was thrilled to find out that I’ll be beta-testing the CC-40 which is great news.  I finally have a 40M antenna that seems to perform quite well – an inverted vee dipole with the center at 47 feet. I’ve never beta-tested a product before, and the idea of doing so is quite novel to me.  I’m not a circuit design person, but am quite proficient at building circuits and kits to other people’s instructions.  This makes me,  I think, closely fit the profile of the kind of people who build kits, and therefore, good material for a beta tester.  That’s my tin pot theory anyway!

I do like to take my own pictures of the projects embarked on here at AA7EE to break up the monotony of all-text blog posts, so as long as it’s OK with Jason, I’ll be posting pictures of the pre-production versions of the CC-40 and letting you know how construction, as well as operation, goes. When at the workbench I’ll have a radio tuned to 7030 and will be eager to try the CC-40 out on the same, or similar, frequency.

One recent update of Jason’s did make me happy, and that is that he has decided to include a sinewave sidetone. This does increase the current consumption of the circuit, but in my opinion,  should make for a much better operating experience.

I’m not quite sure when beta testing will begin, but it looks like it will be a matter of weeks.  As always, ground zero for updates on the CC-40 and CC series of transceivers will be at the upcoming etherkit site and on Jason NT7S’ blog.

January 21, 2011

Etherkit – A New Kit Company

If you follow Jason NT7S’ blog, you’ll be well aware that he has been developing a QRP CW transceiver with low receive current drain that looks like it would make a good trail-friendly radio. He has just publicly announced that his open-source amateur radio company will be called etherkit:

Sorry for lifting your logo Jason.  I know that strictly speaking it’s a breach of copyright, but I’ve linked it to your new site, so hopefully it qualifies as “fair use”!

The first kit offered will be the CC-40, and lifted from this blog post on Jason’s site, here are initial specs.  They may have changed somewhat since he posted these, but it gives you an idea of what will be on offer:

  • RX current draw is now around 30 mA, but I’d like to squeeze it down further if I can
  • TX is Class E, so TX current draw should be pretty good as well
  • Nominal TX output power is 2 W
  • MDS should be around -130 dBm (500 Hz BW)
  • VFO tuning range approximately 40-50 kHz
  • VFO stability is very good (~2 MHz VFO frequency)
  • ATmega88 microcontroller for built-in keyer, mute, frequency counter, battery status, etc.
  • Other planned bands are 80 m, 30 m, and 20 m. Would like to tweak design for upper bands as well for a future date

You can glean some more info from the various posts on Jason’s blog here.

I think the part that interests me is the low current draw on receive.  I already have visions of running my own 40m station with a CC-40 powered entirely by a small solar panel.

Fingers crossed that the beta testing goes well and we’ll be able to buy the CC-40 soon!


In Praise of the 50KW Powerhouse Ham Stations

Filed under: Amateur Radio,Ham Radio — AA7EE @ 5:46 pm
Tags: , ,

During the periods that  I’m active on the bands, I spend most of my time on 7030 or nearby, occasionally scanning down to the bottom of the band at times when there might be a bit of DX to listen to.  Sometimes 40 sounds good, sometimes not so good, but it seems that W6JL is always there, sending very good CW with perfectly readable signal strength. Whatever the condition of the band, W6JL’s signals will be peeling out of the noise, clear as a bell.

Obviously, the title of this post is not factually accurate, but Don”s signal is the closest thing to the ham equivalent of the 50,000 watt powerhouses on the AM broadcast bands at my QTH.  It helps that he’s in Southern California, only a few hundred miles south of me.  He’s not running legal limit power – 550w according to his QRZ entry from his all-homebrew station. Whatever his antenna is, it’s probably pretty high and in the clear. It’s not just his strong signal at my QTH that makes him stand out, it’s the fact that I hear him most every day that I’m listening on 40.  He’s nearly always on, and his QSO’s are not the cookie-cutter type (which I have to confess is my style).  He is so comfortable with CW as a form of communication that he ragchews at consistently decent speeds.  Don sends so much CW so regularly that his signals are the nearest thing to an AM powerhouse broadcast station in my neck of the woods on 40m.

As a QRP op who spends much of my time on or around 7030, I have a strong appreciation for the variety of interesting CW sigs I hear there.  They vary from 599+ to the rather fascinating 319c signals with odd-sounding modulation on the CW note that always makes me wonder just who the signal belongs to and what kind of homebrew concoction it’s coming from. But there’s room for everyone on the ham bands, and there’s nothing like an ever-present signal from a fine operator to show the rest of us what we can aspire to if we keep pushing ourselves with the code. In fact, as I write this, I am hearing him on 7034.

Thanks Don – and for readers of this blog, who is your local powerhouse operator?

Edit: Cam N6GA just e-mailed me with a link to a page that gives interesting information about Don and his homebrew DDS station with a phasing-type direct conversion receiver. You can view it here. Thanks for the info Cam. From the article, it looks as if he is using a 2 element beam on 40 on that tower.  EDIT:  There is an updated version of the page about Don’s station here.

January 6, 2011

The AA0ZZ Keyer From 4SQRP

As much as I tweet about my fondness for building things in Altoids (or Altoids-type) tins,  I have just 3 projects in these useful and affordable enclosures;

a Softrock 40:

an antenna switch:

and a morse code practice buzzer:

When Altoids first became popular, I saved my tins and ended up with around 15-20 of them, figuring that one day they’d be useful.  Then during a move, I decided to get rid of them and now of  course, wish I hadn’t.  I like the older tins because the top lids are not embossed as the current ones are – better for sticking labels on, if I ever want to do that.

Enter the latest Altoids tin project – the AA0ZZ Keyer, a kit from the 4 States QRP Group, and a Christmas gift from my friend Antoinette:

I haven’t put any labelling on this keyer, as is suggested in the instructions.  They even provide you with artwork in pdf form in many different color schemes, to match the different Altoids tins. Perhaps I’ll get around to it, but I quite the look of leaving the tins as they are.  Construction is straight forward – there are very few parts:

I did have one small challenge, and that was in mounting the 3 small pushbuttons. The manual advises the use of superglue in gel form.  Regular superglue is too runny, and can easily wick up into the actual switch mechanism, gluing it shut. I bought some superglue brand-named “Caliber” that claimed to be a gel.  On squeezing out a little onto the first pushbutton, it proved not to have the consistency of a gel, ran into the switch mechanism and glued it firm. It was at this point I wished that an extra pushbutton had been included for mishaps like this. Luckily, 4SQRP will send you 3 extra pushbuttons for $4 inc shipping.  I put the order through and set about gluing the other 2 pushbuttons, using what had been in my mind to use all along – epoxy. I like using epoxy because you have plenty of time to move things around if they are not right the first time, and when it does set, it sets rock solid.  I don’t mind that you have to wait a few hours for it to set – waiting takes no effort 🙂

The 3 extra pushbuttons arrived in a few days.  I sent the order on Friday afternoon and they arrived the folllowing Wednesday. Here’s a close-up of the pushbuttons fixed firmly in place with epoxy.  It doesn’t look too pretty,  but it’s very functional:

And a complete inside view of the keyer:

So far I’m pretty happy with it, but I have noticed two things.  Firstly, it is not possible to change the ratio of character speed to spacing when sending from the memories.  I like to send characters at a slightly higher speed than the spacing between them.  I learnt the code this way – by learning characters sent at 20 wpm with bigger spaces between them. Then when I wanted to increase my speed I simply closed the gaps between the characters. I like sending this way as it encourages the listener to think of each letter as a particular sound rather than a series of dits and dahs. Ideally I would like to program the memories in this keyer to send with a character speed of 15-18 wpm and a spacing of about 12 wpm.

The other thing, which I’m going to have to find an answer to so that I can use the keyer in the way I’ve been wanting to, and that is that I can’t get the straight key mode to work.  I want to be able to send CQ’s from the keyer memory  (on 7030 most of the time) and then break in with a straight key to answer  calls.  I don’t think I’m doing anything wrong.  The manual says that in straight key mode, either the dit or the dah paddle can be used.  I’m pretty sure I have the dit and dah paddles wired up correctly, as the paddle works fine with the keyer in iambic mode.  All the other commands on the keyer work except the straight key mode.  I wonder if there’s a problem with the PIC programming?

I just joined the 4SQRP e-mail reflector and plan to ask the folks there to see if they can help me out. Otherwise, this is a fun little kit (and it only costs $17 at the time of writing).

Order yours here.

Create a free website or blog at WordPress.com.