Mini code practice oscillator

I've been wanting something small and portable that I could carry around with me for doing Morse Code practice. The Heathkit HD-10 oscillator is fun to play with, but kind of big and chunky to haul around. The ARRL code oscillator is small and portable, but the buzzing sound gets kind of unpleasant to listen to after a while.

Then I found Jason's/NT7S schematics for his code practice oscillator (CPO) in his blog and decided to build one. I gathered up the pieces and tried to assemble it on a breadboard a while ago but got distracted by other things and never quite finished.

With the acquisition of some solderable mini-breadboards from SparkFun and the perma-protoboards from Adafruit, it was time to get back to the project. The Sparkfun mini breadboard fits perfectly on top of one of their modular mini breadboards so I put the solderable breadboard on top of the modular breadboard and started laying out the components. Then, once I'm done all I have to do is carefully lift the solderable breadboard off the modular breadboard and then solder away.

After spending some time staring at the schematic and the breadboard pondering how to lay things out, I remembered a suggestion from the kit building forum at the ARRL Centennial Convention. Build modularly and test as you go so that if something doesn't work, it's easier to isolate the problem area.

With this in mind, I started with the power section of the schematic and laid that out in one corner of the board. Add power, flip the switch, LED comes on. Perfect!

The CPO is small and simple enough so that the rest of the circuit pretty much falls into place after that. After a few hours of placing components, double checking placement and debugging, I finally managed to get it working.



With a few wires, I connected my straight key and connected straight to the plug of some ear buds I had lying around. Tapping on the key yielded some pleasant sounding tones, and turning the pot changed the volume (and frequency a tiny bit).


Now all I need to do is solder everything into place, add some jacks and stick it into an enclosure.

A nice, easy build and I was able to do it all with parts I had on hand.

Getting a Canadian amateur radio certificate

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At the ARRL Centennial convention, Connie pointed me toward the Radio Amateurs of Canada (RAC) table after she spent some time talking to them. I spoke to George/VE3YV about RAC and amateur radio in Canada, and in the process learned that because I'm still a Canadian citizen and not a US citizen, reciprocity doesn't apply to me so I can't play radio while I'm in Canada.

We talked about me getting a Canadian amateur radio certificate (it's not a license anymore) while I'm back home in Edmonton in September. Certification exams are given by Designated Examiners (DEs) and if I can find one while I'm home, I should be able to take the test.

Canadian amateur radio certificates come in two flavours: Basic and Advanced. The Basic test is 100 questions with a pass mark of 70%. If you get over 80%, you're awarded a Basic with Honours (or Basic Plus) certificate. The Advanced test is 50 questions with a pass mark of 70% and gives you the full privileges.

Like the VEC program in the US, Industry Canada publishes the question pool for both tests so preparing for the tests would be a matter of collecting the appropriate materials and reviewing them and the questions.

I've had a very quick look at a few of the questions in both pools, and it seems to me the level of knowledge required for the Basic certificate is about the same or maybe a little bit more than the General class license in the US, while getting an Advanced certificate requires a little more electrical and radio theory than the Amateur Extra class.

I've got a couple of months to study and get ready. Piece of cake.

A trip to the ARRL 2014 Centennial Convention

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We made the trippilgrimmage to the ARRL 2014 Centennial Convention this past weekend (July 17-20, 2014) in Hartford, CT. Had a fantastic time and we're so glad we went. We had planned to go a while back, then decided not to go, but then in May (practically last minute) decided that it was an event we needed to go to.

We flew out Wednesday so we could be there for the whole three days. After we got off the plane, we made our way to the bus stop  to catch the bus into Hartford. On the way to the bus stop, we met a ham from Germany, DJ5JH and had a nice conversation while we waited for the bus to show up. We ended up being joined  by a few more hams by the time the bus arrived.

The first day (Thursday) consisted of a number of training tracks. I spent my time in the Intro to Amateur Radio Satellites and learned a lot about the history of amateur radio satellites, how they get into space and how to make contacts through them. Thoroughly enjoyed it and I think it will be another aspect of amateur radio that I will eventually explore. The track ended with an outdoor demonstration of making satellite QSOs through the OA-7 satellite using a handheld antenna and two Yaesu 817s.

Making satellite QSOs

The Thursday training tracks included a lunch with a very inspiring and motivating talk given by ARRL First Vice-President Rick Roderick/K5UR. He told some funny stories about his amateur radio adventures and challenged everyone there to leave an amateur radio legacy and promote amateur radio to youths.

Friday and Saturday was spent in a variety of forums and wandering around the exhibit hall. There was a pretty decent amount of activity in the exhibit hall. Although the flea market area was pretty small, there were a few things I think I might have come away with if luggage space wasn't an issue. I ended up buying a copy of The Best of Idea Exchange from the QRP ARCI table and ARRL's Hand's On Radio Experiments.

There were a lot of interesting non-vendor related tables that were worth lingering at in the exhibit hall. The W1TP Telegraph Museum had a lot of neat old telegraph equipment and a very cool collection of Enigma machines. There was the fully restored 1964 Collin's Communications Van and the working phonograph at the Vintage Radio and Communications Museum of Connecticut table.

One of the highlights of Friday was the trip out to ARRL headquarters and W1AW. There's a pretty impressive collection of vintage and antique radio gear, and the ARRL Testing Lab was a pretty neat area, especially for a geeky type like me. They even fired up Old Betsy, Hiram Maxim's spark gap transmitter, for a little bit. It's a loud beast.

Old Betsy spark gap transmitter

For the convention, operating slots for W1AW were being scheduled in 15 minute windows. I was able to get a slot operating in Studio 1 and operated as W100AW on 20m. Managed to get two contacts in, which I was pleased with. It was pretty cool being able to operate there.

Saturday ended up being a pretty low key day. Went to one forum on antenna modeling and spent some time sitting and people watching, and wandering the exhibit hall some more. Had a Twitter/Reddit meetup in the afternoon where I got to make some eyeball QSOs with a few hams. Always nice to be able to put a face to the online persona.

Sunday was our travel day home, and we ended up being joined on the flight to PHL by DJ5JH. Not only was he the first ham we met in Hartford, he was also the last ham we saw when we left.

More pictures from the ARRL Centennial Convention over in the gallery.

Connecting the microphone

It took a little bit of work and puzzling out wires, but I managed to get the microphone (temporarily) wired up to the radio. In the process, I learned a few things.

  • If you look up the pin numbering for the RJ45 connector (apparently the corrent term is 8P8C), most diagrams have pin 1 on the left side and pin 8 on the right side.
  • Kenwood numbers the modular connector used for the microphone on the TS-480SAT with pin 1 on the right side and pin 8 on the left side.
  • The white and green wires in the Astatic 877L are connected to the PTT switch, but not to anything else. Posts on internet forums say that with Astatic microphones, the white wire is usually the MIC AUDIO line. In the case of this microphone, that's not true. The only wires that count are the red, black and ground/shield wires.
  • Ignore the Internet and stick to the microphone wiring label.

I had a short piece of CAT6 ethernet cable on hand, so I cut that in two pieces, stripped the ends and used some jumper wires to connect the microphone to the appropriate wires on the ethernet cable.

DSC01577.JPGHere's how things ended up getting wired up.

Microphone wire CAT 6 wire Function Pin (Kenwood) Pin (RJ45)
Shield Green/white stripe GND 3 6
Black Blue/white stripe MIC GND 5 4
Red White/blue stripe PTT 4 5
Red White/green stripe MIC 6 3

Wired up like this, the microphone seems to work. With TX monitoring on the radio turned on, I can hear myself pretty nicely through the speaker. The meters on the radio move when I talk. I wasn't able to make any contacts on the radio to get any kind of signal report though.

With only three connections to make, it should be pretty simple to replace the existing microphone cord with my length of CAT6 cable. The only thing I don't like about this wiring scheme is that it puts mic audio on the radio's PTT line. Although the radio didn't seem to protest during my testing, I'm not sure that's a good thing.

I think I'll test out this alternative wiring as well

Microphone wire CAT6 wire Function Pin (Kenwood) Pin (RJ45)
Shield/Green (F) Green/white stripe GND 3 6
White (E) White/blue stripe PTT 4 5
Black (A) Blue/white stripe MIC GND 5 4
Red (C) White/green stripe MIC 6 3

This will separate the mic audio and the PTT lines which, from the radio's perspective, seems to make more sense.

I wonder if I've got a rocker switch in the junk box that I could connect the UP/DOWN lines to. I think there's enough room in the mic base where I could make an opening and add it in.

Pondering microphone connection options

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Starting to ponder ways to connect the desk mic (an Astatic 877L) we picked up last month to the radio. Right now the mic has an XLR female connector on the end, while the radio uses an RJ-45 modular connector for the microphone input. I figure I have a few options:

  • Replace the existing cord on the microphone with some Cat5 that already has an RJ-45 connector on one end.
  • Make a pig tail with an XLR male connector and some Cat5 with an RJ-45 connector
  • Cut the XLR connector off and splice on a length of Cat5 with an RJ-45 connector

Fortunately, the bottom of the microphone has this handy wiring label. There aren't very many wires to connect up to the radio.


Having a look inside the base of the microphone, everything looks to be wired up as shown on the label. It looks like if I choose to replace the cable with a length of Cat5, it will be a little bit of work, but shouldn't be too bad.


From the Kenwood TS-480 manual, the pin-out for the microphone connector is

  • 1 - UP
  • 2 - +8V
  • 3 - GND
  • 4 - PTT
  • 5 - MIC GND
  • 6 - MIC
  • 7 - N/C
  • 8 - DOWN

Looks like red (XLR pin 2) would go to PTT (4) and black (XLR pin 3) I think would go to MIC GND (5). Not sure where the white wire should be connected to, but it currently goes to pin 1 on the XLR connector. The green wire in the mic doesn't appear to be connected to anything.

The downside to replacing the mic cable with Cat5 is that the wires are quite a bit thinner, so I"ll have to give extra thought to strain relief at the microphone base.

Field Day 2014

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Another Field Day has come and gone. I was able to get the laptops set up and networked just in time for the action to start.

This year, the 2PM start didn't sound quite as chaotic or noisy as it did the last couple of years. I'm either getting used to listening through the noise, or it just wasn't as busy this year, or both. I've seen other people mention that band conditions weren't all that great.

I spent the first couple hours logging and keeping tabs on the network connection between the two laptops. Got in a bit of operating before the skies broke open and the torrential rain started. It was bad enough that we had to break down both stations and get them inside out of the rain.

Rain delay

Rain kept us off the air for a couple hours as more rain passed on through, but later in the evening the rain cleared out and we were able to set up one of the stations again.

A rainbow!

I headed back home around 8PM and got back to the ship the next day for the last couple hours of Field Day. Weather was much nicer, and band conditions seemed to be better. I got in an hour of operating and was able to make 10m and 15m contacts into the northeast and northwest.

Me playing radio

Looking at the counts in N1MM, we made somewhere between 600-800 contacts. Because of the wifi dropping out and having to break everything down for the rain, the logs on the two laptops got out of sync. Some operators also didn't want to computer log, so there are some paper logs to add in as well. I think next year one of the things I'll have to do is send out some instructions on how to do the logging, and make a cheat sheet available at each station.

Had lots of fun again this year, and looking forward to next year's Field Day.

Field Day 2014!

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Another Field Day is coming up in a couple of weeks and once again I'll be playing radio with fellow WA4USN club members on the USS Yorktown with CARS. I hope to spend a little more time operating this year.

I'll also be paying closer attention to the generator and battery hook ups to learn how to set up the rig in the shack on portable power. Hopefully the weather is nice and the propagation is good.

ARRL Field Day

Atlanta Hamfest 2014 haul

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Had another great time at the Atlanta Hamfest this past weekend. Was very pleased to see a lot more people outside in the flea market/bone yard area. The hamfest seemed a little more crowded than last year too, which was nice. The inside flea market and commercial area seemed less full than last year though. Maybe everybody was outside this time.

There were a lot of things to see, and I ended up spending most of my time wandering around the bone yard. Came back with a pretty good collection of things this year and could easily have come back with a lot more.

One of the more interesting items, and the first one we bought was this funny toilet mug. We figured it would be a good gag gift for the club's Christmas party gift exchange.

Toilet bowl mug

One of the sellers out in the bone yard had a bin of "free stuff" which had a few interesting items in it. I pulled out a Hall effect transducer kit and a 200 μA meter out of the bin. Not sure if the meter is working, but if it is, it will be nice to put to work in something. The Hall effect transducer kit looks like it will be neat for learning about what kinds of things can be done with them.

Simpson 200 μA meter

Hall effect transducer kit

I also bought a parts bin of various power transistors from the same person. He also had boxes filled with bags of resistors, capacitors and various other random components that I was very tempted to pick up, but I already have a pretty decent stock (actually, probably not) and moved on.

My next purchase was a trio of air variable capacitors. As I was checking them out, the seller said "$3 and they're yours". Too good to turn down. One of them is already geared up with a dial and everything for a VFO tuner.

Air variable capacitors

We had been talking about getting a desk mic for the shack, and found a very knowledgeable lady who's been a licensed ham for over 50 years. Picked up this Astatic 877L mic from her that looked in pretty good shape. One of the rubber feet has fallen off and I'll have to wire up a cable to plug into the radio, but that's no big deal.

Desk mic

The last stop (for purchases) was a table full of a fairly random assortment of items from kits to components to enclosures and more. I think this is where I picked up the bulk of my purchases. Enclosures, a bag of grommets and containers of screws and standoffs, couple pieces of copper clad PCB. One of the enclosures even had some protoboard and resistors in it. This was another one of those tables where I could have picked up a lot more things than I did. He gave me a pretty good price for all the items I took off his table too.


Grommets, standoffs and screws

Wrapped up the hamfest with a purchase of some Dacron rope, some ceramic insulators and a 25 foot length of coax that will eventually feed a 2m antenna.

Pretty pleased with all the things I was able to pick up at the hamfest. And naturally, after we left I was thinking about all those other things that maybe I should have bought too. I guess it wouldn't have been a good hamfest if that didn't happen, would it.