Etherkit Si5351A breakout board three ways

Finished assembling the last of the Etherkit Si5351A breakout boards I received from Jason's Indiegogo campaign. Since I had three of them to play with, I decided to do a few different configurations.


Board #1 is a pretty conventional setup with the header pins pointing up. Lays flat on a surface and could be mounted inside an enclosure if needed.

DSC01987.JPGBoard #2 I used female header pins to make interfacing with my *duino boards easier, since almost all the jumper wires I have are male/male.

DSC01986.JPGBoard #3 I set up to make it easy to use with breadboards. The header pins are pointed "down" so that I can stick the breakout board into a regular breadboard. I also added female headers to the output in addition to the SMA connectors.

DSC01984.JPGI still need to test the boards out to make sure they actually work. I think if I'm going to have any problems with the boards, it will probably be with the soldering of the Si5351A chip.

Building the Etherkit Si5351 breakout board

Spent some time at the workbench putting together the Etherkit Si5351 board that arrived the other day.


Although it's pretty much all surface mount, everything is on one side of the board, and the part count is relatively low so assembly is pretty easy. The fine pitch of the Si5351 chip makes soldering it more challenging, but generous use of solder flux helped the solder flow where it was supposed to go.


After the Si5351 came the TCXO crystal. The large pads make this part relatively easy to solder.


The transistors and 3.3V voltage regulator were the next components to get soldered on. These were pretty easy to do. As with the Si5351, a good amount of solder flux helps with the voltage regulator.


The remaining passive components (4 capacitors and 4 resistors) finish up the surface mount components. These are pretty easy to solder on. Tack down one side with a bit of solder, then solder the other side.


With all the surface mount components on the board, that leaves just the header pins and the edge mount SMA connectors. Easy peasy.


And with that, the Etherkit Si5351 breakout board is finished! Next step is to connect it up to one of my *duinos and see if it works.

I have two more boards to assemble, and some of the things I learned assembling this one should make the other two a little smoother. 

Si5351 breakout boards arrived!

The Etherkit Si5351 breakout boards finally arrived!

DSC01964.JPG(Banana for scale)

It took the Pony ExpressUSPS 13 days to deliver the package from Oregon to South Carolina. According to USPS tracking, it took 7 days for the package to surface in Ft. Worth TX. Then it disappeared for another 5 days before resurfacing in Columbia SC and then being delivered to the house the next day. Using Google Maps to get a rough idea of the distance, the package traveled about 3100 miles in 13 days, or about 10 miles/hour.

I'm looking forward to assembling the boards. Jason did a really good job with the boards. I think the most challenging part will be soldering on the Si5351 chip itself. It's a pretty tiny piece.


I don't have any plans for the breakout boards yet, but there are the usual suspects: SWR meter/antenna analyzer, signal generator, and maybe eventually a radio.


Pictures of the assembly coming up.

NC QSO Party 2015

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Spent the afternoon yesterday playing in the North Carolina QSO Party and finished up with 49 contacts (including 2 bonus stations and 1 bonus county) and 40 multipliers. Like last year, it was all on 40m. There were a few very faint stations that I could hear on 20m, but none clear enough to work.

Haven't worked out my final score yet (over 4000 according to N1MM+), but it easily topped last year's total. Had a lot of fun playing in the contest and it was nice getting back to the radio.

DIY Festival and Amateur radio

The Amateur radio presentation I gave at the Charleston Library's DIY Festival on Saturday went pretty well. Had about 10 people sit in on the presentation where I talked a little bit about what amateur radio is, what can be done with it, the licensing tests and then some construction techniques. To augment my presentation and emphasize the DIY aspect of ham radio, I brought in some of the projects I worked on including some of the Etherkit radios, my Arduino work station and some of the other circuits I soldered up.

There were a couple of people who were very interested, and asked a lot of questions, which was good. Hopefully they continue on to get licensed.

The DIY Festival itself was a pretty neat event. Lots of crafty-type things for the kids and lots of tables with people showing off their craft. Nice to see the Makelab Charleston guys there showing off a few things. One table had a Makey-Makey set up with bananas and carrots, which I saw a lot of kids having fun playing with. Looked like there was a great turnout of people for the DIY Festival.

Charleston Hamfest 2015

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Had another good time at the Charleston Hamfest today. There were a lot more vendors (including in the tailgate area) this year than last year. The day got off to a bit of a cool and frosty start, but warmed up nicely. Good sized crowd of people attending the hamfest. Here are the early birds. Even shortly after 8 there were a fair number of people browsing around the tables.


Started off the day picking up a couple of items off the Free Stuff table: a 1971 edition of the Radio Amateur's Handbook, and a CueCat.


I'm looking forward to going through the 1971 handbook. I think it will be cool to see what amateur radio was like when I was 1 year old.


I remember CueCats from my Apple //e days and always thought it would be cool to have one. Should be fun to play with this.

Browsing around the hamfest, I picked up an Ethernet shield, a big bag of resistors and some perfboard to mess around with.


The Ethernet shield will fit in nicely with the growing collection.


5200 1/4 watt 1% tolerance resistors (100 each of 52 values). I should be set for resistors for a good long time.


2 large plain perfboards, and 8 prototyping boards with solder pads. I like using the perfboard for quick prototyping and experimenting with circuits.

I was also able to find most of the things I'll need to build a window pass-thru block for the antenna.


Two 3 inch SO-239 bulkhead connectors and some screw-on caps for the cable ends.

There were a lot of other things I wish I could have picked up too (isn't that always the case?), but I'm pretty pleased with what I got today.

To top things off, I won one of the door prizes being given out too, a $50 ARRL gift certificate. Not sure what I'll get with it, but it will be something good.

The VE testing session at the hamfest went very well. There were 16 people taking tests today, 9 of whom were taking the Tech (Element 2) test. Everybody left with either a new license or an upgrade, so very successful on all accounts.


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Time to see if I can build myself a crystal radio set. Or two. Or three.

I decided rather than demonstrate building a radio at the Charleston Library's DIYFest, it would be easier to bring in some examples of some simple crystal radios that could be built using stuff easily obtained around the house. Found three nice cylindrical objects and started winding magnet wire.

The inductance of an air wound coil, according to Section 2.12.1 of the 2014 ARRL Handbook, is approximately

L (μH) = d2n2/(18d + 40l)

where d is the coil diameter in inches, l is the coil length in inches and n is the number of turns. Converting it to use more sensible metric units, it becomes

L (μH) = d2n2/(45.72d + 101.6l)

where d and l are in centimeters.

The first coil is 182 turns around a toilet paper tube. d = 4.5 cm, l = 6.7 cm, n = 182, and L = 757 μH.


Coil #2 is 110 turns around the cardboard core of a packing tape roll. d = 8 cm, l = 4 cm, n = 110, and L = 1003 μH.


Coil #3 is 118 turns around an empty plastic pill bottle. d = 4.8 cm, l = 4.1 cm, n = 118, and L = 504 μH.


This is the basic schematic I'm planning on using.


I want the radios to be able to tune in the AM broadcast band (540-1710 kHz) so the capacitance I'll need for coils #1 and #2 is around 10 pF and around 17 pF for coil #3.

Since I have three coils, I think I'll make one with a variable inductor, one with a variable capacitor, and one with a variable inductor and capacitor.

I don't have any high impedance earpieces (I've seen some builds say you can use a telephone handset though), so I might add an amplifier or impedance matching transformer and see if I can get regular headphones to work.

Cards from the buro

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Got my first QSL cards from the incoming QSL card bureau

I had received an email from the SPARC QSL Bureau a few months ago saying I had a bunch of cards waiting for me, and to send a SASE if I wanted to receive them. Sent off an envelope with postage attached, and today they arrived in the mail! So cool!

DSC01947.JPGNow I have 17 cards to respond to. I'll have to figure out how to use the QSL bureaus first.

Charleston Hamfest

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The Charleston Hamfest is coming up in a few more weeks! Looking forward to seeing what kinds of things interesting things I'll want to pick up. There are a few specific things I'll be looking for to build some projects.


Charleston Marathon 2015

Helped out yesterday with comm support for the Charleston Marathon again with my fellow amateur radio ops. Like last year, it was a pretty cool start to the event, but the weather warmed up nicely by the end of the race. This year I was assigned to two positions on the marathon course at Mile 2 and Mile 18.

Had a good time helping out with comm support, and fortunately there were no incidents along the course. Had a good time and I'm glad I was able to help out with the event.