Wednesday, December 09, 2009

DDS Sine Wave Generator

I have not had a chance to experiment with this yet but it's pretty interesting. I ran across a project using an Arduino board from the Academy of Media Arts Cologne where they generate a nice looking sine wave in software from 0 to 16kHz. The project is found here

This picture from the project's web page shows the Arduino board with a low pass output filter and a picture of a generated wave form on the oscilloscope. behind it. The web site mentions they have used a similar system to generate audio tones for a WSPR project as well.


Tim, N9PUZ

Wednesday, December 02, 2009

One of my recent projects was a WM-2 watt meter from Oak Hills Research.

The WM-2 is a solid piece of test equipment with 5% accuracy and three power ranges: 5W, 1W, and 100 mW. I have a couple of small QRP transceiver projects in mind for the winter and the WM-2 seems like it will be a useful addition to my test bench.

Evaluation: The components in the kit are very nice quality. The meter movement and quality of the dial face are very nice. The instructions, while thorough could benefit from a couple of actual pictures vs. drawings in a few places but all in all if you pay attention to the instructions you'll end up with a working instrument right from the start.



Saturday, November 21, 2009

ARRL Sweepstakes - Phone

Pssst, hey kid... wanna do Worked All States in a weekend? This is Sweepstakes Phone weekend. There will be many, many operators on all trying to make as many phone contacts as possible beginning mid-day Saturday. Hope to put a bunch of you in the logbook!


Tim, N9PUZ

Thursday, November 19, 2009

MCP9700A Temperature Sensor Arduino Library

I've done a little polishing on my code for using the Microchip MCP9700A Temperature Sensor and converted it to a library for the Arduino. I'm releasing it under the GPL in case it might be of use to anyone else. You can download it here:


This is my first attempt at an Arduino library. Comments welcome.


Tim, N9PUZ

Tuesday, November 17, 2009

Temperature Sensing on the Cheap

Recently I was experimenting and needed a temperature sensor in a TO-92 type package. After a little searching I discovered the Microchip MCP9700A. This sensor is a bargain at about $0.36 each in single quantities from Mouser.

The interface is dead simple. Vcc, Ground, and an output that you can hook directly to an ADC input of a micro. The part I chose measures from -40C to +125C and outputs 10 millivolts per degree. If you need Fahrenheit temperatures it's easy enough to do the conversion once you know Celsius.

I tested the sensor out with one of the Arduino boards and easily had it measuring and displaying room temperature in about hour.



Saturday, October 31, 2009

Rain, Rain, Go Away

Well, here in central Illinois we just wrapped up receiving many inches of rain in just a few days. I know some of you would love to have a bit of it and believe me if there was a way I'd certainly share.

Over the course of the last couple of days we've had some sump pump problems to resolve. These included:
  • The outlet line plugging up because of the pump sucking up some gravel,
  • Replacing the pump,
  • Having to run a secondary utility pump because so much water was coming in that the regular one could not pump fast enough.
Why would you care about any of this? Well, there's a lot of down time in the middle of the night tending pumps, etc. and I got to thinking about some ways to monitor this ground water situation. There isn't a full formed project in my mind yet but some things I think might be important include:
  • A sensor to detect the water level in the sump well being above a certain level and the pump not running.
  • The amount of time the pump has run in the past hour. Actually, the amount of water that has been discharged would be cool but that might really complicate the system. I don't want the monitoring/measuring to decrease reliability.
  • An audible/visual alert in the main living space if there are problems.
  • A system to send me a text message if there are problems for when I'm not at home.
I'll be giving more thought to this. Other important household things are in the same vicinity as the sump so I may give some thought to anything I may want to watch over in terms of the furnace, etc. as well. All this looks like a job for one of those Arduino boards I've been tinkering with.



Monday, October 26, 2009

Another Breakfast Success!

This past Saturday there was another successful "No Host Ham Radio Breakfast" here in Springfield, Illinois. We had good attendance with I believe about 51 people from quite a few of the surrounding counties.

I highly recommend that people do something similar wherever you live. Essentially I just pick a date and then start talking it up on the area radio nets, sending emails, etc. On the chosen date we meet at a buffet style restaurant for breakfast and spend a couple of hours catching up with old friends and meeting new ones. The only "official" activity aside from eating is a chance for everyone to introduce themselves and mention any local activities coming up with their organizations.

I think the "no host" format is important to the success. By that I mean that there is no club or organization sponsoring the get together. It always seems like there are people who don't like the local club, don't like the nearby club, don't like the ARES group, etc. Yet somehow if there's no organization involved they're able to come eat and have fun. People. Go figure.


Tim, N9PUZ

Friday, October 23, 2009

Looks like the FCC is going to write some rules regarding net neutrality so that broadband providers won't be allowed to provide priority of their own services like telephone, etc. over those of competitors. This NPR story has more information.

I guess I have mixed emotions. On one hand if it's my "pipe" I think I ought to have some rights to provide the best service/speed with my own products. On the other hand I see the desire to make things "even" because in a lot of places consumers may only have one or two options for broadband Internet.


Tim, N9PUZ

Wednesday, October 07, 2009

Arduino, Part II

Okay, I think I'm officially an Arduino fan. At least for one of a kind projects.

The board I recently purchased worked flawlessly. Beyond that a little web searching reveals all sorts of useful add-on hardware that is fairly reasonably priced. There are a host of accessory boards, or shields in Arduino-speak that make your life easier and your project easier. Some of the available shields include plain prototyping shields, ethernet shields, WiFi shields, ZigBee shields, motor controller shields, and on and on.



Saturday, September 26, 2009


Recently I acquired an Arduino Duemilanove. I realize a lot of you probably think I'm coming to the party a bit late but I'm an embedded systems developer by profession and I have all sorts of code snippets for various micros, in-circuit programmers, etc. In short, I've just never had a need to pay extra for a board with a bootloader and software libraries.

A new project came up and it's a "one off" that didn't really justify a custom circuit board, etc. I was searching for reasonable priced boards that used the Atmel AVR processors and was reminded of the Arduinos while looking through the Sparkfun Electronics web site. If you ignore for a moment that they are the Arduino design and have their bootloader the fact is several of these boards are less than $18US in single quantities! They use either the Atmel AVR ATMega168 (16K) or ATMega328 (32K) micro so they are fairly capable in bare form at a price that's hard to beat.

When my board arrived I decided to have a look at the Arduino software and programming environment. I have to say there are some nice looking features and my plan right now is to try things out by using it for this current project.

One more thing that's very cool about Arduino... not only is the development environment, compiler, etc. freely available but it is available in Windows, Linux, and Macintosh formats so you can easily program on your computing platform of choice.

I will report more observations as things progress.


Tim, N9PUZ

Wednesday, September 23, 2009

Reaching Escape Velocity

I love to read. Mostly about technical subjects but frequently about the exploits of others who do what I consider to be really cool things. One such guy is Steve Roberts. He once spent a few years of his life building an outrageous, high tech bicycle called BEHEMOTH then rode it around the country. 17,000 miles of riding. He's on to building a high tech microship now.

This week I got a copy of Steve's book Reaching Escape Velocity. So far it's a great read but it's not about technology per se. It's about how to launch gonzo engineering projects with the help of sponsors, volunteers, and a little help. Details of the book are here along with order info.


Tim, N9PUZ

Sunday, September 20, 2009

Winlink Testing -- Success

The Winlink Testing mentioned in an earlier post was a success. Over a two day period the only two stations that appeared in my "heard" list were KA9VAU and KA9STB. Both were far enough away that it had to be a VHF band opening and not potential interference.

I will make an announcement in all the usual places but by the end of the month N9PUZ-10 and N9PUZ-3 will move to 145.610 MHz.


Friday, September 18, 2009

Winlink Testing

Around noon local time on September 18 I switched the N9PUZ-10 RMS Packet gateway to a frequency of 145.610 MHz. That's the designated ARES digital frequency for Illinois. I'll be leaving it there through the weekend to monitor for any other heard traffic and to give anyone who cares to listen a chance to monitor for beacon messages, etc.

I anticipate moving the gateway and the N9PUZ-3 (alias SPI) packet digipeater to 145.610 MHz by the end of the month unless some unforeseen problem comes up.


Tim, N9PUZ

Thursday, September 17, 2009

New Web Site... The Work Continues

Work is slow but steady on the new, revamped web site. You can get a peak at the new N9PUZ now.

Sunday, September 13, 2009

A Full Weekend

It was a ham radio weekend here. On Saturday I went to do a site survey in Carlinville, Illinois. I'm helping the club down there set up a VHF Winlink 2000 Gateway similar to N9PUZ-10 that I operte in Springfield. The Illinois ARES organization has an initiative to make Winlink 2000 available in each of the State's 102 counties and we're trying to do our part.

Sunday was the Capitol City Century bike ride. My home club, the Sangamon Valley Radio Club always coordinates APRS trackers and phone operators for SAG vehicles, rest stops, etc.

This coming Saturday is the annual Peoria Superfest. One Illinois' larger hamfests. I'm making my list...


Tim, N9PUZ

Friday, September 11, 2009

Web Site Updates

I'm in the process of making some updates to my main web site. It's going to undergo some much needed reorganization and I'm moving it to a different host.

The new site will be hosted at My old domain name and web site are still active at and once the changes are a little further along that domain name will be pointing to the new site.

Thanks for all the reader support!


Tim, N9PUZ

Friday, September 04, 2009

ARS Spartan Sprints

The first Monday of each month, September 7th this September, is the monthly ARS Spartan Sprint. The sprints are short, fun QRP contests. It is a contest but these are really friendly operators. They'll go as slow as you need them too and don't be surprised if you get a short rag chew when you meet someone new. Only two hours. Lots of fun.


Tim, N9PUZ

Monday, August 10, 2009

'ZO Fest 2009

This past Saturday, August 8 was the 2009 edition of ZO Fest in Bloomington, Illinois. ZO Fest is the annual gathering of the Society of Midwest Contesters, a group of dedicated contesters and DXers in Illinois and neighboring states.

As usual a god time was had by all. Ralph Bellas K9ZO is the chief instigator and every year he and the other line up some of the best contesters, DXers, and DXpeditioners in the Midwest to share stories, experiences, and tips with the group.

I've had a day to rest up now and I'm already looking forward to 2010!


Tim, N9PUZ

Sunday, July 26, 2009


The last Sunday of July is always the Adventure Radio Society's Flight of the Bumble Bees contest. It's a four hour, low key QRP event that encourages people to head to the outdoors for an afternoon of fun operating.

I was only able to operate for a little over an hour and logged just two contacts. The propagation really stunk here today.Still, it's an enjoyable event that I particularly like because most of the ops call CQ at reasonable speeds that mere CW mortals can copy.

Highly recommended for your calendar in 2010!


Tim, N9PUZ

Friday, June 26, 2009

It's Field Day Time!

It's the eve of Field Day. Saturday and Sunday many, many ham radio operators will switch their radios to battery power or haul entire stations into the field. There they will operate for up to 24 hours trying to rack up as many points as possible in the ARRL's annual non-contest.

Do you participate in Field Day? How? Some people operate from home. Others participate with a group. Some are serious about racking up points, others use Field Day as more of a party with friends.

My plans are to participate in two Field Day events. Our local club, Sangamon Valley Radio Club tends towards low key operating and a big Saturday evening cookout with all the families, etc. The local ARES group, Capitol Area Amateur Radio Emergency Response Team has a smaller more serious effort. Both groups seem to have a lot of fun.

It's going to be very hot here in central Illinois. Whatever you do, if it's outside drink lots of water, have fun, and stay safe.



Sunday, June 14, 2009

Support Your Local Hamfest

We read a lot about the big mega-Hamfests -- Dayton, HamCom, Pacificon, SeaPac, Huntsville, etc. Many of us travel to one or more of them a year in search of bargains, to renew old friendships or perhaps meet an "on air" friend in person for the first time. They are great!

Don't forget to attend and support your local hamfests though. They are treasures in their own right. Today my wife and I went to Egyptian Fest in Granite City, Illinois. 2009 marked their eightieth (that's 80 not 18!) year.

I remember going to the Egyptian Radio Club hamfest back in the 70's when I was first licensed. I'd rummage through old equipment having no idea what a lot of it was. Even though I wasn't buying the old grey beards would explain the equipment to me and perhaps share a story about people I hadn't met and how they had used this or that to first get on the air or make a rare contact. It was an enjoyable day I looked forward to each year.

Egyptian Fest is still a small, friendly hamfest. Today for their 80th birthday they pulled out all the stops with not one but two guest speakers plus a presentation on D-Star that I was unable to attend due to talking with too many friends while I should have been listening!

First up was Bob Heil K9EID of Heil Sound. Bob showed a presentation that described a little background on the company and then did an interesting presentation on microphones, articulation, and what you want to be heard effectively on the air.

Second up was retired FCC Special Counsel Riley Holingsworth K4ZDH. Riley talked about human nature in general and hams in particular. Along the way he shared a few humorous stories and then took questions.

Not every small hamfest will have speakers like Bob and Riley. But an awful lot of them have some pretty sharp people talking about some aspect of the hobby they love. If you don't go take advantage of them you're the one who's missing out.

The local hamfests are a good place for second chances too. Remember that vintage equipment I mentioned earlier? I'm pretty sure I saw a few of those same radios in the outdoor swap area today!


Tim, N9PUZ

Tuesday, February 24, 2009

New Rig at ARS N9PUZ

After several years of great service from my Icom IC-718 I've replaced it with a shiny new Icom IC-7200. I really liked the IC-718. I had added the W4RT dual filters to mine and that made for a nice HF rig that had great performance in a compact, easy to use package. I always said the only way Icom could have improved the IC-718 was to replace the audio chain DSP with a nice IF chain DSP like they have in thier higher end rigs like the the "Pro" series. Perhaps they heard me.

The "Big Brown Truck" brought the IC-7200 yesterday. After only one evening I've decided I really like this radio. The variable DSP filtering simply blows away the mechanical filters I had in the IC-718. You can adjust the bandwidth for CW and USB modes in 50 Hz increments. The radio remembers the "wide", "medium", and "narrow" selections you make for each mode. The display is nice and crisp although a little smaller than the old radio. It is very easy to read.

I'll be writing more as I gain experience. I was able to try this radio and a Yaesu FT-450 and this one seems like the clear choice to me. If you are in the market for a $1,000 class HF rig this one bears close consideration.

The old IC-718? Fear not, I didn't put it out to pasture and it's not gathering dust. A Ham down South bought it and I've already had a note from him that it works great and he's enjoying it.


Tim, N9PUZ

Monday, February 16, 2009

The RF Gain Control - Unsung Hero of Your HF Rig

A lot of times when I talk to Hams that are new to HF operation they mention how bad noise (QRN) and interference (QRM) can be. They often wonder whether adding an external DSP or internal crystal filters will eliminate the problem. Well, these accessories can help but new operators, and perhaps you as well, may already have one of the most effective tools in combating interference and noise.

The RF Gain control on your transceiver is the unsung hero of HF operation. It provides a variable means to reduce the strength of all of the signals coming in to your receiver. Used properly it can very useful in picking out just the signal you want. Here are the basics...

First off, if the band is just generally noisy like 40 and 80 meters so often can be, use the RF Gain control to reduce the static and noise levels you hear when you are not tuned to a signal until the noise is just barely audible. Then starting scanning for stations to work. If you're not trying to snag some rare DX station or pass an emergency message then there's no reason to make your rag chew tedious by hearing all that noise. As long as you can hear the other station does it really matter if the meter indicates S9 or S2?

Next, lets say you find a station to work but there is some QRM or QRN making it tough to hear them in spite of the adjustment you made earlier. Try this: Turn the RF gain control to minimum. You may hear nothing at this point. Then, turn the volume control up very high. You still may not hear anything. Now, use the RF Gain control (not the volume control) to control the volume of the station you want to hear. A lot of times this will make the easy to copy while drastically reducing the junk you don't want to hear.

Remember to turn down the volume control before you increase the RF Gain when you move on to the next QSO or things will get VERY loud! Once you practice this a little and get used to it you'll wonder how you ever got along before.