Category: Operating

Operating, QRP, SOTA

SOTA After Action Report – Sheridan Peak

Posted on by Jason Milldrum

Thanks to the efforts of Etienne Scott, K7ATN, we who live in the Pacific Northwest have a couple of nice SOTA summit-to-summit activity days each year. One that happens in early spring and if I remember correctly the other which occurs later in the summer. I participated in the spring S2S Party two years ago, but haven’t had a SOTA activation since.

As mentioned in a previous post, things have been kind of crazy here lately, and Jennifer has been encouraging me to get out to do something I enjoy, so I decided to take this Saturday to participate in the S2S Party. I was considering Bald Peak, which is just on the outskirts of the Beaverton-Hillsboro area, and makes for a quick and easy trip, but by the time that I went to Sotawatch to claim it, I noticed that K7ATN had already done so. Thanks to SOTA Maps, I was able to easily browse some other peaks relatively close, and settled on Sheridan Peak, especially since a previous trip report tagged it as a fairly easy drive and hike.

I needed a travelling companion, so I asked my 5-year-old son Noah if he wanted to go, and he eagerly agreed. I wasn’t sure if that enthusiasm would hold up during the trip, but at least because of the short hike to the summit, it would be easy to bail out if necessary. So we departed the house at around 9 AM, stopped by McDonalds for a light breakfast and a large coffee for me, then took the backroads of Washington and Yamhill Counties out to Sheridan Peak.

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The drive was uneventful, other than my phone’s GPS getting a bit lost at the very end of the trip. However, the driving directions from the two previous write-ups of this peak on pnwsota.org were great and got me right to the parking lot. Actually, the gate to the parking lot was closed, but that was OK because there is a nice big turnout on the road immediately below it, so we just parked there and walked around the closed gate.

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The hike up to the summit was quite easy, and Noah did well for one of his first actual hikes. Unsurprisingly for a peak in the Oregon Coast Range, the weather was damp and showery. Although we didn’t have much of a view from the top due to the forest, one big advantage of that was the canopy over our heads providing a bit of a break from the rain.

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Fortunately, I was prepared for the rain, and I quickly erected a tarp shelter for us to use to take cover from the elements. It was actually fairly cozy under the shelter, as another advantage of the tree cover was that it was acting as a nice wind break from the usual chilly blast you get on a peak.

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I don’t currently own any HF portable gear, but thanks to the generosity of W8NF, I was able to borrow a Yaesu FT-817 and Elecraft T1 tuner. A few days prior to the activation, I cut a random wire and counterpoise that would at least work on 40 and 20 meters, and tested it in my backyard. That turned out to be a good thing, as I was able to get my wire in the tree and get the 817 QRV with no problems at all. I also brought along my Baofeng UV-5R with rubber duck/tiger tail combo for 2 meter FM ops, with the 817 as the designated backup if that didn’t work.

At the designated time of noon local, I heard K7ATN full quieting on 2 meters (which wasn’t a huge shock, as his peak was only about 20 miles away from mine). There wasn’t a huge turnout for this activity day like there was a few years ago when I did it on Cooper Mountain, but I did manage to make four S2S QSOs on 2 meter FM with the UV-5R in order to officially activate the peak. Woo! After that, I switched to 40 meters LSB on the 817 and made a couple of S2S QSOs with stations that I had already talked to on 2 meters and one with a local chaser. Finally, I had K7ATN spot me on 20 meters and managed to squeak out a couple more SSB QRP QSOs, both with stations in Arizona. By then, Noah was getting a bit cold and wanted to get going, but I was pretty happy with the results. From the sounds of things on 2 meters, a few of the other activators had some pretty crummy weather conditions to deal with, especially NS7P on Mary’s Peak.

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So after about an hour on the peak, Noah and I packed everything up and headed back down the half mile or so to the pickup. I was very proud of Noah, as he did great for a 5-year-old; never really complaining and obviously really enjoying being out in nature, plus I think he liked the radio activity as well.

I’m really happy to have made this activation, especially since I was able to get Noah involved in both an activity out in nature plus radio fun! Thanks again to K7ATN for all of the hard work that you put into the PNW SOTA community and the rest of the activators for getting out there in this wet spring Oregon day. Stay tuned for hopefully one or two more SOTA activations this year, hopefully with more family members coming along on future trips.

Edit: Here’s a recap of the event from K7ATN.

2
Etherkit, Operating, Wideband Transmission

Wideband Transmission #7

Posted on by Jason Milldrum

More Musings about Etherkit’s Future

As I mentioned in my previous post, we are still undergoing a stage of tremendous upheaval in our household. I won’t really know how our new life will shake out quite yet, but I am certain that my time will be more restricted. I think I’ll have a good grasp on the extent of this within a month or so. In the mean time, I’ve been thinking about Etherkit. It’s a bit weird to air this out on the blog, but I think it would be good for others to hear my thoughts about this and have the chance to offer feedback.

The assumption is that I’m going to have less time to work on Etherkit (the only real question being how much less time), which means that if I do have enough time left to continue with the business I will need help by either outsourcing manufacturing or finding someone to bring on as a partner. If possible, I’d like to go that route, as I’m not really ready to see Etherkit fold up yet. This would also require more funding, so I would probably have to find a way to raise capital via the sale of equity, or perhaps I could crowdfund enough on a future product to keep things afloat.

Right now I have in the product pipeline OpenBeacon 2, which is perhaps 80% finished (most of the remaining work is in firmware), and a handful of small useful RF modules. On the drawing board I have a couple of QRP transceiver designs utilizing the Si5351 that would definitely fall into the category of cheap and cheerful, and would probably be a lot of fun to bring to market. Also, since OpenBeacon 2 is based on the Arduino Zero, I’ve been discovering the power of the Atmel SAMD series of ARM Cortex-M0+ microcontrollers. I’d love to develop a dev board derivative of the Arduino Zero using some of the SAMD line that have a bit less flash storage and consequently are a bit less expensive. I think hams (and other hackers) would really like such a device.

The other option is that due to time constraints I just cannot realistically continue Etherkit as an active business (at least regarding retail sales of physical stuff). If that happens, then I would still like to stay active in some way, under the restrictions in my available time. Perhaps writing may be a good choice, since that is quite portable and can be picked up and set aside a lot easier than designing electronics. Writing technical books, for a new blog that earns money somehow, or as a contract writer for an existing website are all possibilities. I’ve thought it might be nice to write about test and measurement for the ham’s home lab.

Either way, I’m not done with the ham homebrew community. The open question is merely how much time I can still give. Let me know what you think about the above in the comments.

Back to the Shack

It’s been a while since I’ve transmitted any RF on the amateur bands other than the testing that I’ve been conducting for OpenBeacon 2. Between how much time I’ve been putting into OpenBeacon 2 (and refining the Si5351 library), it’s been very difficult to find the time to sit down to operate. On top of that, I honestly just haven’t felt much of the operating mojo, so unsurprisingly I haven’t even tried to make it a priority.

Generally, it’s not great to force these things, but I’m getting to the point where I’m feeling a bit disconnected from amateur radio and that I really need to be QRV again in order to rebuild that connection. The ARRL Centennial in 2014 was a great operating year for me because it gave me a concrete and interesting goal to pursue.

W1AW WAS

So I figure that I need something similar to get me motivated again. A good goal perhaps would be to finally finish up basic DXCC from this QTH. As of right now, I stand at 75 confirmed entities in LoTW. It shouldn’t be that difficult to get 25 more confirmations in LoTW by the end of the year, especially if I carve out a couple of weekends for contesting. I used to chase a lot of the big DXepditions as well, and that might be another good source to pick up a handful of ATNOs (assuming I pay whatever fee they charge for a prompt LoTW upload). I’d also like to actually get a successful HF SOTA activation or two under my belt, and this would be a good summer to do that.

The League

Speaking of the venerable institution, I let my membership lapse recently. Not really with the mind to do so, but given the rather significant dues increase, it was becoming a bit more difficult to justify the expense. Yeah, they are only asking $10 more per year, but I have to ask myself if I’m getting $50 of value every year.

I was honestly barely reading the QSTs that were arriving in the mail. However, the archives always have been one of the best features of the membership. I’m glad they do work with the FCC to represent our interests. Their lab does a good job of evaluating products. It feels that their organizational structure is a bit too ossified; a bit too hierarchical for my tastes. Getting feedback to the leadership seems difficult if you aren’t already connected to leadership.

On the balance, I’m generally pro-ARRL, but I still don’t know that I see the value of just forking over $50 annually. I understand why they needed to do a rate increase (although it probably would have been better to phase it in more gradually rather than a 20% hit all at once). I also understand the economics of why it would be difficult to offer a membership without QST, unless a paper QST was scrapped entirely. I would be curious to see how the rate increase ends up affecting their member numbers and their bottom line.

0
Operating

2014 Ten Meter Contest

Posted on by Jason Milldrum

Since moving to the current QTH, it has now become something of a tradition for me to operate in the ARRL 10 Meter Contest. The last few years of the contest have been enjoyable since we’re on the peak of the solar cycle, and I don’t have to stay up all night to catch stations, meaning I can still sleep and have some family time. I think Radiosport is fun, but I just don’t have time for much of it with my other obligations. This is one of the few times I get to indulge and spend a significant portion of a weekend sequestered in the ham shack, clutching a mug of coffee.

I always enter the SO SSB QRP category of the 10 Meter Contest, which is a pretty lonely category, presumably because of the relative difficulty. One nice thing about entering the category is that there may only be one or two entrants from your section (or even division!), so the chances of scoring some wallpaper is pretty good, even if you put in a fairly minimal effort.

Since I have no illusions about competing with the LP and HP entrants, my main goal each year is to beat my previous best score. Since my score from last year was 7,490, I figured with a bit of effort, I should be able to get to at least 10,000. So that was my goal for 2014.

Over the last few years, I’ve just used my stock station equipment for the contest, which means an Icom IC-718 (turned down to 5 W PEP of course) and a ZS6BKW doublet up about 30 feet (probably not the best pattern on 10 meters). I figured that I was going to have to up my game a bit in the equipment department in order to make a big jump in scoring, especially since we are now past the peak of Cycle 24. So I decided on a two-pronged attack to the problem: I needed a directional antenna and a way to process my speech to give me more readability for the same RF output power.

I’m on a limited budget, so purchasing a brand new commercial beam wasn’t in the cards, but fortunately it’s fairly easy to homebrew a decent 10 meter antenna. After putting out the #lazyweb call on Twitter for some antenna plans, Robin G7VKQ pointed me to some simple plans for a 10 meter Moxon.

These plans looked like they would be just about perfect for me, since I already had a lot of 3/4″ Sch 40 PVC pipe and fittings. A Moxon doesn’t have quite the raw gain of a 3-element (or more) Yagi, but it does have a very nice front/back ratio, which means a lot of my 5 watts should be only going where I want it to.

So a trip to Lowe’s a few days before the contest secured me the remaining supplies that I needed (mostly the 1-1/4″ PVC pipe and fittings) and I was able to construct most of the antenna in my garage in one afternoon. I had to extrapolate the PVC measurements from the plans on WB5CXC’s web page a bit, since the fittings I purchased no doubt had different dimensions from the ones he used. I also ended up using some spare stiff steel wire that I had left over from a previous project and some Lexan as the spacers between the driven element and reflector.

Here’s the completed Moxon up on my 6 foot ladder for testing and tuning. Using the DSA815-TG and my HFRLB return loss bridge, I was able to see that the initial resonance was around 27 MHz, and quickly got it trimmed up to a center frequency of about 28.7 MHz.

Once tuning was complete, I put the antenna up on 15 feet of 1-1/2″ Sch 40 PVC mast, secured to a 2×4″ support screwed into the eaves of the house and another one on the ground held down with a sandbag.

Some quick checking of the efficacy of the antenna by tuning in a JA station, then moving the antenna off-axis with my Armstrong rotor, indicated that the front/back ratio of the Moxon was indeed very impressive.

WIth the antenna situation well in hand, I just needed to get my speech processing in place. For that, I went to my Elmer, Dave W8NF, in order to borrow one of his LogiKlipper LK-1 prototypes. The LK-1 provides an adjustable amount of RF clipping (not audio processing) and the ability to interface with just about any commercial amateur radio imaginable. With the addition of a headset and footswitch, I was able to confirm on a second receiver that the LogiKlipper was working and that the adjustable clipping settings had an effect on my readability.

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By the time that 13 December 0000Z rolled around, I was still attending to some family business, but I was able to get into the shack at around 0030Z to try to pick off a few stations before the band closed here at dark at around 0100Z. I pointed the Moxon to about 300 degrees and worked a KH6 right off the bat, but then something awful happened. A horrible, very bad, no good bit of wideband QRM popped up on the entirety of 10 meters. There seemed to be two components to it: a wide rushing noise at a constant S8 or S9, then a pulsing buzz (at about maybe 0.5 Hz) peaking at about 20 dB over S9.

I whinged about this on Twitter and some suggested that I go DFing for the QRM. That’s a worthy suggestion, but I’ve never done that before, and I probably would have spent the entire contest trying to figure out the how to do it, which didn’t seem like a trade-off I wanted. I could still hear the strongest stations (although the pulsing would sometimes even wipe them out on peaks), and I was really only interested in working the strongest stations any way, as a SSB QRP station. So I decided to just grit my teeth and press on.

I woke up at daybreak on Saturday and was able to get in the shack right away. Usually if there’s propagation to Europe, I’ll hear them on 10 meters first thing in the morning, but there was almost nothing I could hear, and certainly nothing I could work.  However, there was good propagation to New England, so I was able to make quite a few QSOs there; usually able to make a contact with anyone who was loud with a call or two. Later in the day, propagation opened up to the Midwest, followed by the South (and a bit of the Caribbean), then the Plains and Mountain West states (but no Dakotas!). In the early evening, I wrapped up with a run of JAs.

The first full day ended with a score of 8282 and 101 QSOs, which was already better than my previous best score. It didn’t seem like it would take much effort to beat my 10,000 point goal at this point, barring something catastrophic like an equipment failure or solar blackout.

Up again at dawn on Sunday (one of the “benefits” of having young kids), the bands seemed to start off a bit slower. I did manage a few QSOs to the islands off the western edge of Europe, but still nothing in Europe proper. But by about 10 AM local, things seemed to pick up significantly, at least for North American propagation. Since I was hearing a lot of the same big contest stations as the previous day, my strategy was to spend a bit more time calling new mults. The entire time, I was still dealing with that terrible QRM, which was not that much of an impediment to hearing most of the time, but was awfully fatiguing.

There was also a bit of assistance and moral support from my two sons, which was much appreciated.

The second day of contesting went much like the first, at least as far as propagation went. I was able to get more DX mults on Sunday, as the pileups for those stations died off and my small signal was able to compete a bit better in the smaller piles.

When all was said and done, I ended up with just a bit over 20,000 points; more than double my initial goal!

My QSO total was 182, which indicates that I didn’t quite get as many QSOs on day 2 as I did on day 1, probably because I spent more time chasing mults. I think that was a good strategy overall, but I probably could have chased non-mult QSOs a bit harder on the 2nd day had I been super-motivated.

This is obviously a subjective view, but propagation for this contest didn’t seem quite as good as last year. I didn’t hear nearly the amount of EU stations that I did in 2013. However, domestic propagation was still pretty great, and I was able to make plentiful QSOs from stateside stations. Those mults are just as valuable as DX mults, so it wasn’t terrible that I didn’t get much in the way of EU QSOs. I did manage to work almost every state except for the states immediately surrounding Oregon, with the exception of Rhode Island and North Dakota. I didn’t hear as many Canadian stations as I would have expected, but I did seem to have a pipeline into Manitoba. I posted my score to 3830, but that’s just a condensed version of what is here.

I believe it’s safe to say that equipment upgrades played a significant role in my much-improved score. How much credit goes to each is probably impossible to precisely define, but I’m content to call it 50/50. As always, the contest was a ton of fun, and allowed me to hone my station equipment and operating skills. I’ve set the bar pretty high if I plan on beating this score next year. As the solar cycle continues to decline, I’m going to have to do even more on the antenna front to give me a fighting chance to beat 20k. But for now, I’m content to have done so well and had such a good time.

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CC-Series, Etherkit, Homebrewing, Operating, QRP, Wideband Transmission

Wideband Transmission #5

Posted on by Jason Milldrum

Latest CC1 Progress

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As you can see from the above photo, I have finished a significant portion of the digital side of the newest CC1 prototype and now I’m on to the receiver section. This weekend I finished my first pass of the audio chain and characterized the gain and frequency response of the chain. Next up is the design of the IF and front end of the receiver. This time I plan to do a much better job of characterizing the performance of entire radio, designing for specific critical receiver specifications, and iterating the design as necessary instead of holding on to dodgy performance from circuits.

Mixer Investigations and the Search for Better Dynamic Range

Since I decided to ditch the dual-gate MOSFET mixer front end, I’ve been considering what to replace it with. At first, I was thinking about using the ADE-1 for the mixer and product detector, but I’ve been intrigued with reading about H-Mode mixers over the last few weeks, which led me to the similar, but simpler KISS mixer by Chris Trask. That seemed like a good candidate for the CC1, with relative simplicity and better-than-average performance. Since good IP3 performance is the main characteristic of this mixer, I wanted to try measuring IIP3 at my own bench to see how it looked in a home made circuit with less than optimal parts and layout.

To get warmed up, I first attempted to measure the IIP3 of a few parts that I had on hand where I already knew IIP3 values to expect: the SBL-1 and the ADE-1. Using a DG1022 as the signal generators, my HFRLB as a hybrid combiner, and the DSA815TG, I was able to measure an IIP3 of +13 dBm for the SBL-1 and +17 dBm for the ADE-1, which is pretty much right on what other people have published.

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Here is my test setup for measuring the KISS mixer performance. I deviated from the circuit described in the KISS mixer white paper in a few ways. First, I used a TI TS5A3157 analog switch, as I didn’t have any Fairchild FST3157 on hand. I also used a hand-wound trifilar transformer on a BN2402-43 core instead of a nice transfomer from a company like Mini-Circuits. I drove the KISS mixer with +3 dBm from a Si5351. My measurement of IIP3 for this variant of the KISS mixer came out to +27 dBm, which seems reasonable given the poorer components I was using. Conversion loss was 7 dB. I’m going to try to measure it again with an actual FST3157 and a Mini-Circuits transformer in the near future, so it will be interesting to how much that will improve the IMD performance.

But honestly, I probably won’t need better than +27 dBm performance if this mixer is used in the CC1. Since the CC1 is meant to be a trail-friendly radio with modest current consumption, I don’t think I want to include the high current amplifier needed after the KISS mixer to get maximum performance out of it. Which is kind of a shame, but I figure that I should be able to keep RX current to around 50 to 60 mA and still have a receiver with better IMD performance than your typical level 7 diode ring mixer receiver. Stay tuned for more details on the CC1 front end as they are worked out in the NT7S shack.

10 Meter Contest!

Yes, it’s almost time for my favorite contest of the year: the ARRL 10 Meter Contest. Ever since I moved into the current QTH, it has been a bit of a tradition for me to operate the contest as SSB QRP only. By virtue of entering that least-liked category, it has been no problem to collect some modest wallpaper from this contest. That’s fun, but my real goal is to beat my previous score. Last year, I think I did fairly well with 7490 using a stock IC-718 and my ZS6BKW doublet. So this year, I’m going to have to step up my equipment game in order to have a good chance of besting last years score. I’m thinking some kind of gain antenna is going to be a must. If I can get a Moxon or small Yagi up around 20 feet and use an Armstrong rotor, that should help give me a little more oomph than last time. We’ll see if I can get something built in the less than 3 weeks before the contest.

4
Cool Stuff, Design, Homebrewing, Operating, QRP

For Noontime Net

Posted on by Jason Milldrum

I’ve been working on getting the little bugs out of the Si5351 SSB rig and making improvements to the circuit. Since SSB QRP operating can be a bit more challenging than CW QRP ops, Dave AA7EE suggested that I think about a speech processor IC to use in place of the op-amp microphone amplifier. He directed me to the Elecraft K2 schematic, which uses an Analog Devices SSM2166. I poked around the Analog website a bit and found a sister IC called the SSM2167. It’s smaller, simpler, and cheaper than the SSM2166, which could make it perfect for this radio.  I ordered a couple of samples of each from speakerxpert and they rush-shipped them here within a few days.

So today I got around to installing the SSM2167 in the 40 meter SSB radio, set the compression level to about 10 dB, and took a look at the transmitter waveform on my oscilloscope (I can still kind of see the screen if I get some light shining on it from the side). There is a single resistor which sets the compression level, and by jumpering around it, I can set the level to 0 dB. By comparing the waveforms with compression at ~10 dB and then off, I could tell that the average transmit power was increased quite a bit with compression on.

Next, I decided to check-in to the Noontime Net to see how it would work on the air and hopefully get an audio report. Luck would have it that net control Leslie N7LOB was very strong here, so I knew I should have no trouble checking in today. Also I was fortunate to have a strong signal from Lynn KV7L, the gentleman who donated the SA602s that are used in the radio. I’ve got a raw clip of my check-in below, which I hope to incorporate into a more polished video a bit later.

As you can tell from Lynn, 10 dB of compression might be a bit much for something like checking into a net. I changed the resistor to set compression at around 6 dB, which should be more appropriate for this type of use. It also sounds like some folks on the Noontime Net want to see some photos of the rig, so here are a few taken with my tablet. Not the best quality, but it should give you an idea of what it looks like until I can get my “real” camera back and take better photos.

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6
SOTA

SOTA After Action Report – Cooper Mountain

Posted on by Jason Milldrum

About a week and a half ago, I received an email from Etienne K7ATN, asking me if would be able to participate in an event he organized called the Portland Urban S2S Party. In a nutshell, this was an effort to get activators on as many of the “urban” SOTA summits in the Portland area so that we could all work each other on 2 meter FM simplex. That sounded like a lot of fun, and as it turned out, the nearest peak to me (Cooper Mountain W7O/WV-099) was unclaimed. It also worked out nicely that this is a very easy summit to access due to the fact it is essentially in a suburb and would require only a short hike.

(I injured my left knee/quadricep with a tear a bit over a year ago, and I’m currently in physical therapy to work on improving it. I can walk, but ascending and descending anything is difficult for me. Fortunately, I can now do a bit of easier hiking)

The event time was set for 26 April 2014 at 2000 UTC. I grabbed my dusty IC-T7H with quarter-wave whip, notepad, and waterproof windbreaker and made the short 15 minute drive to the road near the summit. That was easy to find thanks to a nicely documented summit report from K7ATN.

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The footpath between the houses was easy enough for me, but the final ascent to the recommended operating spot was a bit tough because of how wet the ground was. In the above photo it looks like there is lots of wild grass, but the roots were very shallow, as every step up the hill resulted in a bit of a muddy slide backwards. However, I managed to slowly make my way up the hill without injuring myself further and found a dry spot under a tree to set up shop.

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I arrived a bit early, so I turned on the HT and heard K7ATN on the designated frequency holding some QSOs. A quick call to Etienne confirmed that I was getting out OK, so I sat down and waited for the net to start.

Cooper Mt - Op Position In Red
Cooper Mt – Op Position In Red

At 2000, K7ATN kicked off the net and had a total of 13 check-ins from local summits. I was able to hear everyone else except for the station on Mary’s Peak, which wasn’t a total surprise, as that summit was directly south of my QTH, while I was on the north side of Cooper Mountain. Below is a map of the summit-to-summit QSOs that I made in the event.

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I’ll let K7ATN’s summary speak for the results, but I had a great time getting out for my first real SOTA activation, even if it was a bit of weaksauce in the adventure department. It was great to get back out and do a bit of hiking and ham radio in the outdoors. Thanks to Etienne for the invitation and the rest of the participants and chasers for a damn fine afternoon of SOTA fun.

1
Cool Stuff, DX, Operating

The Final Courtesy

Posted on by Jason Milldrum

The final chapter of the Hi Juno event has arrived at the NT7S shack. After months of waiting and wondering if my reception report was received, I returned home from a SOTA activation to find the beautiful Hi Juno QSL in my mailbox.

Hi Juno QSL Front
Hi Juno QSL Back

Thanks to the folks at JPL who coordinated this intriguing event and took the time to QSL all of us crazy hams who participated. The Hi Juno QSL will definitely sit as one of the specially treasured ones in my collection.

Here’s to a successful mission!

1 Gallery
Cool Stuff, DX, Ham Culture, Operating

We Make Contact

Posted on by Jason Milldrum

My last blog post (from two months ago, sorry about that) detailed my participation in the worldwide Hi Juno event; a coordinated effort from amateur radio operators from around the world to send a very slow speed Morse Code signal (HI, to be exact…DIT-DIT-DIT-DIT DIT-DIT) to the Juno spacecraft as it slingshotted around Earth on it’s way out to Jupiter.

After the attempt, the Juno science team promised an update to let us know how the experiment turned out, but was very quiet over the last few months. Worse, was news that Juno had tripped into safe mode during the Earth flyby. There was a decent chance that no usable data from this experiment would be recovered. Suddenly, yesterday on 9 December 2013, there was a press release announcing that there would be a presentation on the results of the Juno Earth flyby, including results from the Hi Juno experiment, and that this presentation would be streamed online. This morning at 10:30 AM, I eagerly connected to the livestream to see what they would announce.

Hi Juno Spectrogram
Hi Juno Spectrogram

In short: we did it! As you can see in the spectrogram above, our signals were detected by the Juno spacecraft in a couple of different time slots. The green dits are the signals that were actually detected by Juno, while the gray ones are anticipated signals which were not detected. One thing is slightly misleading about the spectrogram, as it appears that our actual signals are not depicted in it. I’m not sure why that is, but I imagine it is for clarity in public outreach. Still, as a ham, I would love to see the spectrogram without the overlay of the expected data. One other thing that is interesting is the streaky lines in the upper right-hand corner. It is said that these are terrestrial SW broadcasters.

The Waves instrument primary investigator said that there were at least 1400 hams who participated in the experiment (I assume that is based on the number of QSL requests sent through their email address). If you assume that each was running a barefoot commercial rig (I was, but had it dialed back to 50 W just to go easy on the finals), it’s not hard to imagine that collectively we put around 100 kW of 28 MHz RF out there for a few hours.

Perhaps this stuff is too obscure for the average person to care about, but in my view this is one of the most inspiring and amazing things I’ve done in amateur radio. You can see a bit of my raw reactions from Twitter below:

It’s pretty rare for a space agency to reach out to the public at-large for active participation in a spacecraft science experiment. The fact that we were able to pool together and successfully transmit a signal to space probe whipping around the Earth at very high velocities just boggles my mind. I also have to give a huge huzzah to the team who created the public outreach website for Hi Juno. It was top-notch and did a perfect job in coordinating all of us hams around the world. I hope that the success of the Hi Juno experiment will encourage science teams to consider similar future efforts when possible.

It does seem that the Hi Juno experiment had quite an impact on the science team, as it inspired them to create a short documentary about the event and the results, which you can see below. It’s very well produced and exciting to watch. There is also a shorter video which just shows a depiction of reception of the Hi Juno signal. Now I just need to wait for my Juno QSL to arrive…

UPDATE: Here’s a press release about Hi Juno from the mission page.

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Cool Stuff, DX, Operating

Hi Juno After-Action Report

Posted on by Jason Milldrum

As I write this, the Juno spacecraft has completed its slingshot maneuver around Earth, having stolen a bit of Earth’s rotation energy. and is now on its way out to Jupiter. A bit before the designated 1800 UTC start time for the event, I was able to set up my Icom IC-718 at the appointed frequency of 28.324 MHz with an output power of approximately 60 watts CW.

I executed the hijuno.py script via SSH (as mentioned in my last post) a few minutes shy of 1800, turned on my handheld scanner so I could monitor the transmit frequency, and waited for the show to start. I also checked a few WebSDR receivers to see if I could detect how many hams were participating in the Hi Juno event.

Hi Juno Website
Hi Juno Website

The transmitter started up, but immediately I could see that it wasn’t in sync with other stations that I could hear and see on the receiver. My shack PC is running Ubuntu 13.04 and it set up to automatically set its clock via NTP, but obviously it was off by quite a bit. So I had to duck into the shack quickly to manually update NTP, then come back to my laptop to restart hijuno.py via SSH. This time, I could see by following along with the interactive Hi Juno website and listening to my transmit monitor, that my timing was correct. As you can see above, the website had a nice graphical display of when to key up and key down for those doing this manually. That little yellow triangle at the bottom of the screen moved from left to right to indicate the current position within the transmit timing window.

W5ZA WebSDR
W5ZA WebSDR

At this point, satisfied that the Python script seemed to be working, I went back to WebSDR for a listen. The W5ZA 10 meter beacon receiver in Shreveport, Louisiana seemed to be a great choice for monitoring all the Hi Juno signals out there, probably because it was still in daytime, as opposed to the European receivers, which seemed to be showing nothing. Normally this would be considered bad, but I have to think in this case it was a good thing, since the ionosphere was probably not reflecting 10 meter signals back to Earth in this part of the world, and they were free to make it to Juno. To the left, you can see a screen capture of the W5ZA WebSDR just after a Hi Juno keydown period.

The rest of the event was fairly…uneventful. The Python code worked perfectly and stopped transmitting at the right time. It was fun chatting on Twitter with other hams who were also participating in the event. Based on watching the WebSDR waterfall and checking Twitter search, it seemed like there were quite a bit of us taking part in the event. I have no idea, how long it will take for us to hear back from the investigators whether this worked or not, but I hope it’s fairly soon. I’m definitely looking forward to getting a QSL. My first one from an interplanetary spacecraft. I also have to say that the Hi Juno website worked wonderfully during the event with its simple and clear graphic instructing you when to transmit, and showing you transmit window. if we ever get more opportunities to participate in experiments like this in the ham community, it should be a model on how to run things. Even though we didn’t get any immediate gratification, it was a fun event and I hope that NASA/JPL reaches out to us again in the future.

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Etherkit, SOTA

Wideband Transmission #3

Posted on by Jason Milldrum

Polyvaricons Now For Sale

I’ve decided to try a small experiment and see if there’s any interest in selling a small selection of components that would be handy for RF experimenters. The first product I have up for sale (in limited quantities at this time) are four-packs of the somewhat-hard-to-find polyvaricon variable capacitor for only $10. Please head on over to the Etherkit store to get the details and to purchase a pack. If this is successful, I may keep selling them and branch out into some other RF rarities.

Behind the Scenes in Kitbiz

Think that your local small-time kit business is raking in the dough? Probably not. This blog post from ch00ftech does a wonderful job of explaining the economics behind small-batch kitting and will probably give you a new perspective on all of the expenses incurred in such an endeavor, including many which may not be obvious to you at first. Although in this particular instance, the author was not particularly trying to make a profit, the post still captures the process involved, even for those who wish to earn a few bucks from their toil, brilliantly.

World’s First Mt. Hood SOTA Activation

Here’s a really neat write-up (with photos) of the very first SOTA activation of Mt. Hood, the tallest peak in Oregon (11,249 ft [3,429 m] tall). Well done, KB3QEW!

Lower Prices on the For Sale Page

I’ve lowered the prices on most of the items on my For Sale page, so please get over there and take a look at some good ham gear and test equipment!

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