I’m very impressed by Texas Instruments. They’ve been on what I call the ‘Arduinish’ bandwagon for a long time with the ‘Launchpad’ MSP430 starter kit. Now, they’ve added a few more Launchpad kits for other processors such as the Stellaris and Piccolo processors.

But Tech Days was really cool. They had a LOT of good classes, and a mini trade show where many of the TI Partners displayed their wares. Many freebies like USB sticks, back scratchers, coolies and lots of good data sheets and catalogs.

But the best … was a small piece of paper in the TI bag they gave at the entrance. Subtle. It says ‘Tools for 10’ and when you read the fine print … it’s a $500 gift certificate!! WOW!

I’ve ordered a $400 DSP starter kit to learn DSP on. I chose one that had lots of audio features hoping it will help me learn DSP filtering and things like that. I can’t wait!

Still to arrive is the Stellaris Launchpad. There are a LOT of plug ins called ‘Booster Packs’ which are similar to Arduino shields. In fact, some of them are compatible but I don’t understand it well enough yet to explain which ones and why.

SO, keep a watch out for more cool freebies, downloads, classes, and inexpensive toys as I note them here on the blog and of course on the Wednesday Night Tech Net.

Tracy N4LGH

As mentioned on the net, the UCF club found our QRM scanning the band and took some movies. These are from April 13.

Thanks for a great net! Dayton is going to be full of Orlando this year!

During the net I mentioned the Texas Instruments MSP430 Launchpad dev kit that
they sell for $4.30. That’s right, under ten bucks shipped. And everything is on
line and free. It has a format similar to that of the Arduino, but a flavor all
its own. TI and others are offering ‘Booster Boards’ that add functionality
similar to ‘Sheilds’ on the Arduino.

There is a free IDE (development environment) for programming in either assembly
or C and there is a huge support group that can help with virtually anything. I
was impressed.

Here are the links I promised –
(in no particular order …)

Also experimenter / ham projects –
iambic keyer among other things, overall really good site
Another keyer
same guy, good linux discussion and LOTS of info.

Hope you have some fun exploring this – consider getting into it or something
like it!
Tracy N4LGH

Go to the 147120_projects Yahoo group to discuss thebest time and day for the return of the central Florida Tech Party. Vern, KI4SDY proposes the return of the Tech Party to Longwood – Join in the discussion and lets get this party started!

Wednesday, January 11, 2012, 8PM Eastern Time
“Same Tech Time, Same Tech channel!”

New format, new equipment, new year … Technet!

Arm yourself with your radio, armchair and network connection for an evening of excellent technical exploration.

Tracy N4LGH

Tonight I did a ‘dry run’ with the Tech Net … after nearly eight months off the air, we had 15 checkins and an hour of great discussion.

We’ll be back next week at the regular time – see you there!

Look at this crew ;]

Burt Nate Homer Roy Jim Dave Vern and John at the last weekly tech party to he held at Verns. Another fun and productive meeting!

The only thing consistent is a constant state of change
What a great tech party. We’ve had a great year!
All things must change, and so with the Wednesday Night Tech party. Vern announced that there is a health issue in his family and he is needed at home.
We all appreciate the marvelous host that Vern has been since the establishment of the BiTX20 builders group and the ensuing Solder Social which grew into the Tech party.
Thank you, Vern! We wish you all the best and pray for a full recovery.
Burt and Nate studying intensely!

Burt and Nate checking out the data ... note all the cool digital toys surrounding them. Click the picture for a closer view.

The Tech Party needs a new facility. Perhaps two? Vern says he can probably host one meeting a month after a bit. Which got me to thinking, what if we did three tech parties a month, one at Verns, then one near the east side and one near the west side? Perhaps a ‘triangle’ with Vern to the North and spots to the Southwest and Southeast. That way everyone will have one tech party per month that is ‘closer’ to them.
Before we got the BiTX project going I had started doing the Technet from guest locations – Local amateurs homes, restaurants, parks, etc. So moving around isn’t a new concept to the technet, shouldn’t be a problem for the tech party, don’t you think?
This is a large metropolitan area and so there will never be any one location that is more convenient than another. There will always be someone excluded because of distance. This way I think more people will have a chance to participate.
SO, if you have an idea for a facility please email or leave a comment on this article. This coming Wednesday we’ll probably take the night off – if we haven’t secured a facility by then everyone is invited to my place in Winter Garden until we find locations more convenient to everyone else.
This past Wednesday was a lot of social but we got some great discovery done in the microprocessor world. I gave Nate a couple of PIC chips to play with on his new proto board and encouraged him to pick up a PIC programmer. There was some really god discussion on the various development kits available for the PIC, AVR and STMicro uP’s.

Coming along nicely! the crystal filter is installed, but needs to be tested, as is the audio amp. Go Vern!

The BiTX project is coming along nicely for most. More of us are conquering the VFO, although we will need to do a session on the VFO circuit again to learn to recalculate the other capacitors in the system to accommodate different values of variable capacitors.
I found this awesome calculator online. Can someone get this figured down to C code? This is nice –
Most of the guys have populated the crystal filter and audio amplifier portions of the board but haven’t tested them yet. Jim has almost the entire board stuffed, he’ll be mounting it in a chassis soon! This is going to get exciting when we start putting these things in enclosures and getting them on the air!
The next meeting, wherever we are, will be spent mostly on testing. We’ll have the IFR to run them on and several of us will have lab power supplies to run them with. It will be a hoot, ya’all come on out now, ya hear? ;]
Tracy N4LGH


Jims Coverage

Jim used a larger value variable capacitor, so his VFO has more frequency coverage ...

Well, mostly conquered
Jim has a capacitor that is way more than 50 PF. So it’s time to learn series and parallel capacitance, resonant circuits and probably something else. No, I’m not going to dive into it here, admitingly I have to learn that myself! However, there do seem to be some calculators out and about that should help.

As you can see in the picture his VFO covers a lot more than just the 20 meter band. For some that may be just fine. What it does, though, is limit the ‘resolution’ of your tuning dial. The radio does have a nice fine tune adjustment to compensate for that.

This is the disk!

This is the SD 'disk' that we used to update the Flash (U-Boot) on the NGW100. It's an older card that the older U-Boot could handle.

Another big breakthrough at the Party was the flashing of Das U-Boot. Yah, we have flashing Das U-Boot! Dave sucessfully formatted an SD card the way the NGW100 likes, we moved the Atmel Flash Upgrade Utility to the SD card, and told U-Boot to load the image. It was cool! Took seconds flat and now reports U-Boot 2010.8.

This is important to anyone who has an NGW100 as this upgrades the ‘bootloader’ in the board to be able to read 2GB cards. The U-Boot bootloader that ships preloaded in the card won’t read the cards with large blocks. We’ve been stuck with older cards, usually 64 and 128 MB. Dave had one card that was 1GB with the small block setup. That’s the card we ended up using to load the flash image.

Vern, Ralph and Roy

Vern, Ralph and Roy doing what we do at the Tech Party!


We had quite the group for the first Wednesday of the month. Remember there are several other groups that meet the first Wednesday of the month so the Technet and Tech Party are usually kind of light. We did great this week though!

Remember EVERYONE is invited to our group – you don’t have to be involved in any of our current projects to attend. The social value of this group is immeasurable! From time to time the group leader does focus the attention of the group to a specific point, but other than that this is definitely a multitasking group.

Jim, Nate and Bert

Jim, Nate and Bert working on Jims VFO - conquored for the most part, it's on frequency but covers more than the 20 meter band because he used a larger variable capacitor. What we need to do next is calculate the new capacitors to set his bandwidth.

Ejhngofarten nkne hbgrlop

Roy and hbgrlop being entertained by some of the technical magic that happens at every Tech party!

Jims VFO

Jims VFO with Vern and Dave in the back

Let the knowledge flow

It is absolutely the best thing in the world to have a room full of Elmers an aspiring techs. Here is Jims VFO showing the large range of coverage he has, with Vern and Dave in the background digging in to their projects.

Jims VFO

Here's Nate working on Jims VFO. Note the neat setup Nate made with some protoboards and a neat 'laptop' type case he found at Skycraft. This week his creation sported individual switches for each of the power busses, 12, 5 and 3.3v regulators and a lot of spirit for the next run of mods!

Here is a closer view of Jims setup and the frequency. Also note the power supply showing 80 mA current at 13.8v. Keep in mind the entire circuit is not powered, just the VFO and display.
See you next week!
Come out to next weeks Tech Party! Log in to the net on 147.120 Wednesday at 8pm if you can’t make it in person. There’s always something good going on and now n then there’s munchies! Never be afraid to bring munchies – you become an instant hero of the 147120 Tech Crew ;]

Last Wednesdays tech net was a raving success! Although there were only a handful of us there we finalized the defeat of our shortcomings with the Bitx20 VFO. What’s best, is that we used the tools that WE BUILT to test it! woo hoo!!

lower frequency

Lower Frequency

Upper Frequency

Upper Frequency

Verns VFO
is the first working properly. With the caps that Dave got from Mouser Electronics (Part # 23PW156; Film capacitors; styrene 50V 560pF) and the replacement variable cap, this puppy is dead on and unbelievably stable! The poor little am radio cap just wasn’t happy; it was shorted or possibly corroded, either way it was ‘jumpy’ every time we tried to do anything with it and we just couldn’t figure out the little trimmers on the back.
Replaced the Capacitor
The original was a little rusty or something

nice open air capacitor

reduction and variable capacitor

I had picked up a small ‘offcenter’ variable cap off ebay some time ago. The value is the same as the one in the kit so I was confident it would plug right in. I had built a small reduction on a 6:1 vernier giving a total of 30:1. Yup, it takes 15 turns of the knob to go from one end of the band to the other – 10 KHz per turn at the bottom end, and 20 KHz per turn at the top. Not bad!!

We used the FLL frequency counter kit we had built a couple months ago to test the VFO. It turned out to be a nice little tool for tuning the circuits in the BItx20. Verns ended up having a coverage of apx 3.998 to 4.352 – again very nice! Verns price for the reduction? He has to make the transceiver look really good ;]
The Perfect Setup?
Good enough for Nate!

In Operation

In Operation

The test was done on top of Nates neat setup he is building for his breadboard. He found a ‘briefcase’ type box at Skycraft and attached his breadboards on top of it, leaving room inside for all his accessories. In this test we used the power buses to make hookup much easier. Below is a view from another angle. Note the power supply showing the unit drawing 90 mA at 12v – backlight and all! Of course just the VFO and Frequency Counter are powered right now.

The Setup

The Tech Party BItx20 Setup!

We really did have a lot of fun with this one. Vern had to rewind his toroid several times, finally finding a smaller diameter wire in order to put his final 54 turns on the core. It is spec’d at 50 turns, but it ended up being too high in frequency. When he tried to go over 50, it was not in a single layer winding with the wire provided to the inductance was way off. The final verdict – 54 turns with #32 wire on the core provided. Yay!

hot glue

Fastening the toroid with Hot Glue. Once on, simply press the core against the board before the glue sets and this little circuit is good n' stable!

Vern really likes hot glue. Every time he wound a core he’d glue it down for testing. We finally convinced him to just glue the final result down. When dealing with things like this, like the inductor in an oscillator, physical stability is very important. Gluing the core down will keep it from moving and causing minute ‘microphonics.’ Good job Vern.

Fine Tune arrangement

Fine Tune Control

The Fine Tune Control gives almost a perfect 3 KHz shift – a little over 1.5 KHz each side of center. That’s extremely nice as all you have to do is tune ’em in so you can hear ’em with the main tune, and then adjust ’em so you can understand ’em with the fine tune. As designed and described!

So we were able to conquer the VFO – now on to the next stage. There are several builders going on to the audio stage next, a couple into the mixers. Next week we’ll discuss who is where and what new challenges we may face.
The Meeting Was A Smash
and we had a good time, too!

All in all we had a great tech experience, a great tech net, and a great result from the evening! I hope to see you next week at the tech party or at least check you in to the Wednesday Night Tech Net.


On Wednesday at about 8:00 pm local time is the 147.120 Tech Net.
You can find the Tech Net on the 147.120 MHz repeater (KJ4PLD) with a CTCSS tone of 103.5

the 147.120 Tech Net "net-operator"

Tracy (N4LGH) running the Tech Net

Here Tracy (N4LGH) acting as the Net Op at Vern’s Barber shop.

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