Last Chance Hammin'

Perhaps that's a bit melodramatic, but my time for operating and homebrewing is going to be severely curtailed very soon. Baby Boy Milldrum will be arriving any day now (the estimated due date is July 22) and we're in full-blown panic mode as we finish the last minute preparations to get the baby's room ready, make sure we have all of the assorted baby stuff that's needed, and take care of those homeowner chores that need to be done for the summer. So I figured that I should take some free moments to enjoy the hobby while I can. Sometimes I feel like every blog post here should have some really meaty and meaningful content, but perhaps that inhibits me from posting more than a few times a month. So prepare for this post and many of my future posts to cater a bit more to the short attention span crowd. I'll have to get my ham radio in small doses whenever I can, so expect a bit of ADD to set into the blog for a while.

Anyway, my inbox has been blowing up with DX Sherlock alerts telling me that 6 meters has been open most evenings over the last few weeks. I finally broke down and dug out the Buddipole components on Friday so I could try to snag a few QSOs on 50 MHz. I managed to grab a few SSB QRP QSOs with the FT-817 into VE4 and VE6-land on Friday night using the Buddipole in a simple dipole configuration. The band was in great shape that night, as I could hear a lot of East Coast stations coming in quite strong via multihop Es. On Saturday, I tried to work CW QRP on 50.096 MHz but had zero success even after calling CQ many, many times. The band was open and there was still plenty of activity on the SSB portion of the band, but CW was a bust. Come on CW ops, we've got to do better than this.

I still managed to make it a interesting ham radio night. After packing in the gear from the back deck, I went into the shack, flipped on the HF rig, and checked 20 meters (just around sunset local time). Very soon I stumbled upon the legendary Martti, OH2BH calling US West Coast stations. After a quick tune-up, I was able to snag him within about 4 calls. He was absolutely booming into Beaverton (by the sounds of it, he was booming into the entire western portion of the US). This was my first QSO with Martti and was memorable to be sure.

Moving on to a more unpleasant topic, am I the only one who things that most of the ham mailing lists are dying of a creeping mediocrity and groupthink mentality? The big two QRP-Ls are mostly a joke as far as getting an interesting, topical discussion going. On the other hand, start bitching about computers or some other off-topic old fart rant, and you'll get 30 messages a day. The SKCC group made me sick with its virtual pitchforks-and-torches assault on the new owner of Vibroplex because he had the audacity to replace the stamped brass identification plates with a silkscreened version. The way that a few prominent members of that group (including one who is affiliated with a competing key manufacturer I might add) character assassinated the owner was quite disgusting.

This provides a nice segue into another topic people love to hate: Twitter. I quit tweeting a few months ago due to the large jackass/decent person ratio that I was experiencing. I thought I would miss it quite a bit, but once I got over the DTs in a few days I didn't really miss it much at all. I still debate whether I should go active on Twitter again, because I see some utility in it; but even when you remove the jerk factor, it still feels like drinking from a firehose most of the time. Not to mention that huge time sink that results from checking your account all of the time make sure you are up-to-the-minute on the latest crap. What to do?

Finally, a plea. Some of you may know of qrpedia.com, which I tried (and failed miserably) to turn into a QRP/homebrewer aggregated blog and knowledge repository. It's already in sad shape, but with the new kid coming, I know I'll have no time to devote to it, so I need to let it go. I don't want to nuke the site because there are a handful of people who put a lot of hard work into posting content there. I would like to sell the site for a nominal price and have it go to someone who could give it another chance. Please contact me if this interests you at all. Prices and terms are very negotiable.

Dayton/FDIM 2010 - Days 2 and 3

Hans Summers Presenting at FDIM 2010

Please accept my apologies for the long delay in posting my impressions of Hamvention and FDIM. I was literally on the move every waking hour of my time in Dayton on Thursday, Friday, Saturday, and Sunday. Up about 6 AM to shower, at Hamvention all day, then FDIM at night. Back to N8ZM's house around 11 PM to crash in the easy chair. I've never worked so hard to have fun. My writeup is going to focus mostly on FDIM, since that was the main reason that I was in Dayton. I probably can't give you much information about Hamvention that you haven't already heard thousands of times from other hams. Besides, the muse has taken leave from me again, so I don't want to butcher this recap any more than is necessary.

My adventure in Dayton got off to a proper start on Thursday, which was seminar day at FDIM in Fairborn. I arrived around 7 AM, which was a bit early, but I got a chance to get a seat pretty close to the front of the room. By the start of festivities at 8 AM, the room was pretty much full. There had to be more than 200 attendees (I unofficially heard that this was the best attendance at FDIM in a few years).

There were a total of six presentations for the day. I'll give you a brief rundown of my impressions of each one.

  • K8ZT - The morning started off with a presentation by Anthony Luscre, K8ZT about strategies for being successfull in QRP contesting. The PowerPoint deck for this talk came in a over 140 slides, which meant that Anthony had to rip though the slides at a lightning pace. He gave some good inspiration to those of us who have not yet taken the QRP contesting plunge.
  • G0UPL - Next up was world-class homebrewer Hans Summers, G0UPL. His presentation was about his QRSS efforts. About half of his talk covered information that is already on his website, but he did get into some areas that I haven't seen him cover before. I especially enjoyed seeing his natural power battery experiments. At the end of his talk he announced the sale of a kit version of his latest QRSS transmitter, which I'll cover later on. He came with the stereotypical dry British humour (LOL), which I enjoyed immensely.
  • G3RJV - My favorite talk of the day was given by the legendary Rev. George Dobbs, G3RJV. He did a masterful job of combining a grand tour of simple receiver designs with more philosophical aspects of our hobby. You can tell that Rev. Dobbs has honed his public speaking skills quite well from his years in church.
  • NE1RD - After lunch break we were treated to a great talk by B. Scott Andersen, NE1RD on the topic of his 100 Pound DXpedition. While the 100 Pound DXpedition is not a QRP-specific topic, NE1RD put a QRP spin on the talk by focusing on his recent CQ WPX QRP efforts on St. Thomas.
  • K8IKE & K4ZLE - Jim Everly, K8IKE, and Jay Slough, K4ZLE brought a power-packed presentation about  acquiring a set of "good enough" test gear for the homebrewer and how to use this gear to perform a useful subset of the ARRL lab procedures for RX and TX performance. We also had a bit of good-natured sarcastic side commentary from Ed Hare, W1RFI from the League's lab. This was extremely useful stuff and I wish that they had a little more time to delve into this topic.
  • K9AY - The final talk of the day was from prolific FDIM speaker Gary Breed, K9AY. He covered low band QRP operating; mostly focusing on the challenges of deploying a useful DX antenna on these bands. Gary brought some good information, but unfortunately he had to compress the end of his speech quite a bit because he ran long in the first half. Fortunately, the proceedings had all of the information that was skimmed over.
FDIM 2010 Thursday Vendor Night
FDIM 2010 Thursday Vendor Night

After a long day of sitting and listening to speakers all day long, we had a few hours to get up, grab some dinner, and stretch our legs. By 8:00, the main ballroom was reconfigured for QRP vendor night. The room was not 100% filled with vendors (as you can see in the photo to the right, most of the tables in the middle of the room were empty), but there was still quite a bit to see. Hendricks QRP Kits had the largest display, but Diz from kitsandparts.com was probably a close second with his huge stock of 'roids, components, and RF Toolkits. As I mentioned earlier, Hans Summers announced the sale of his latest QRSS transmitter as a kit with a PCB and a microcontroller that he would custom program with your callsign. This was the most popular item of the night. For nearly the entire two hours of Vendor Night, there was a large line of people waiting to purchase a kit and have it customized by G0UPL. I hope this sparks a lot more QRSS activity here in the States.

K3PG Sonic Tray Chassis Willamette
K3PG Sonic Tray Chassis Willamette

One very neat aspect of the night was getting to meet a bunch of the QRPers that I've known for years via the mailing lists but have never seen in person. Some of the highlights that stand out for me were my introductions to WA0ITP, K3PG, K8IQY, NM0S, KC2UHB, W8DIZ, and WB8ICN (sorry if I missed anyone!). It was a pleasure to finally be able to shake hands with my peers and mentors. I'd like to give a special shout-out to Diz for his salty greeting! That's the way to make a guy feel like a part of the gang from the first minute! I loved it! It was also a treat to have a good, long conversation with K3PG, whose enthusiasm for the Willamette was truly humbling, as well as infectious. Chatting with WA0ITP seemed like two old friends talking. I've collaborated with him so much via e-mail that it seemed perfectly natural to pick up where the electronic communications left off.

I hate playing favorites, but I think the true highlight of the night was meeting Mikey, WB8ICN. I was sitting in the lobby of the Holiday Inn, working on my laptop and waiting for the Vendor Night festivities to start. I wasn't paying much attention when a couple set down in the chairs opposite from me. They were having a lively conversation for quite a while, but I was engrossed in reading the FDIM Proceedings CD that I purchased earlier in the day. After a while, the gentleman sitting there was getting more and more animated in his conversation. At that point, my curiosity got the best of me so I had to check out what was going on. Something seemed vaguely familiar, but it took me a few moments before I saw the shirt with "WB8ICN" embroidered on the chest. Of course, I got up and introduced myself to Mikey and his wife Marybeth, which seemed to take him by surprise a bit! We had an awesome conversation and were probably getting a bit louder than we should have been. That was the only time we got to talk at Dayton and I wish I had more time to BS.

I'm only going to skim over Friday, since it was a bust regarding FDIM. Hamvention was as large and as crazy as everyone had said it would be, especially the flea market. Sometimes I get a bit overwhelmed in such huge venues, so I wasn't really acclimated to what was going on until Saturday. I imagine that I looked like a lost puppy dog wandering around. Hara is pretty old and decrepit, but that certainly didn't slow down any of the activity. The only thing that was really "offensive" to me about the place was the bathrooms. I never used them at Hara, but just walking within 30 feet of the entrance was enough to make me want to gag. I think I still have nightmares about the smell alone. God help anyone who actually had to use them

Due to a bit of a communication error on my part, I didn't make it to Friday's FDIM activities until the event was almost over for the night. So I'll just skip right on past that and get to the good stuff about the Saturday night banquet in my next post.

The Clackamas QRP Transceiver

Clackamas Schematic

Since FDIM 2010 is in the history books, it is my pleasure to finally publicly release my entry into the FDIM 2010 QRP Challenge: The Clackamas 40 Meter Transceiver.

The rig is a VXO-tuned superhet that operates around 7.030 MHz. The heart of the design is the BF998 dual-gate MOSFET (which was popularized by W7ZOI on his website and in EMRFD). The BF998 is used as the front-end mixer and as a combination product detector/BFO. My new favorite AF amp, the TDA7052, is my choice for the single allowed IC. The VXO signal is mixed with a carrier oscillator in a JFET mixer, which is then bandpass filtered and fed to a BS170 power amplifier.

Please download my contest writeup for full details of the design. I'll dissect the design in further detail in future posts.

More Willamette Pix

I recently received a couple of excellent photos of completed Willamette transceivers, and I just can't help but brag on these wonderful creations.

W8BH Willamette with Digital Dial

W8BH completed his rig quite a while ago but recently upgraded it by adding a KD1JV digital dial. Looks very sharp, Bruce!

K3PG Willamette in Sonic Tray Chassis

I'm really getting a kick out of this one. K3PG, appropriated an old Sonic drive-in tray to create a chassis for his Willamette. I really enjoy seeing the more mechanically inclined hams build cool enclosures out of interesting scraps. He did a great job with the shielding between the VFO and mainboard. FB work Paul!

All Buttoned Up

Clackamas in TPC-41 Enclosure

Yesterday I got the Clackamas all dressed up nicely in its new Ten-Tec TPC-41 enclosure. I have such a stack of bare, half-finished circuit boards laying in the shack that it's always a real pleasure to get a project to the point where it's well enough developed to put it in a case. It's also much nicer to operate the rig when you don't have to fumble around with holding a pot or switch in one hand while trying to work the control with the other. One valuable lesson that I've recently learned about the mechanical side of things is that a step drill bit set is an indispensable time saver, especially when you have many different sizes of holes to drill in the same enclosure.

The rig is all ready to make the trip the Dayton for show and tell. In the meantime, I'm going to try to make a few more QSOs with it when I get a few spare moments. Hope to catch you around 7.030 MHz.

Sweet Success!

Over the last week or so, I've been coming home from work nearly every morning thinking about ways to tweak the Clackamas (FDIM 2010 QRP Challenge) rig. I'm sure that Jennifer is wondering if I have OCD at this point. This morning I was able to stamp out the last few bugs in project and get the parts count to 72. There was a nasty PA oscillation that I had to tame and I was having trouble pulling my carrier oscillator low enough to get the transmitted signal on the right sideband. Somewhat satisfied that the thing might actually work, I went to sleep with the hope that I could try a QSO this evening when 40 meters would give me a better chance of making a QSO.

After dinner I managed to slip into the shack after Jennifer laid down to rest and I bribed Baxter to leave me alone with a Kong full of treats. I thought about trying to self-spot in order to scare up a QSO, but that didn't seem right. I wanted the first QSO to stand on the rig's own merits, not because I asked someone to listen for me. So I parked somewhere near 7030 kHz and started banging out a straight key CQ with 1 watt output. After about 5 rounds of CQ, I started getting the sneaking suspicion that I had screwed something up, but I trusted that my pre-QSO checks on the rig were correct. So I kept at it.

After a few more CQs, I finally got my reward. A huge signal about blasted the phones off of my ears! And it was saying my callsign! I got a reply from W7MDK in Peck, ID. I was so excited that the QSO didn't go so great, but we got all of the pertinent information across. He was going a bit faster than I normally copy, and I think my speed was impaired even further because of my extreme excitement. Dick gave my 1 watt a 579, while he was easily 40 dB over S9 here. I cut the QSO short to stop me from embarrassing myself further, but I got the first one in the log!

It's said that there isn't much better for the homebrewer than to turn on that newly created receiver and hearing signals off the air for the first time. It's hard to argue with that, but I think that making a complete first QSO with a rig you designed and built yourself has to top even that experience. Sorry to toot my own horn so shamelessly, but I'm just thrilled with the love of radio right now.

The next steps are to get going on the documentation for the judges, get the prototype into an enclosure, and start working on a second copy of the rig to make sure I can duplicate it from the schematic. I can't wait to share the design details with everyone, but that's going to have to wait for another month or so. In order to get the rig within the required parts count, I had to trim the receiver down to 34 parts. The transmitter ended up being 30 parts and the VXO came in at 8 parts. However, I was able to make the Clackamas a true transceiver, not just a trans-receiver.

Stay tuned for additional details as I can release them!

Update: Just worked JF2QNM in the JIDX contest. 1 watt spans the Pacific! Of course, all of the credit goes to the op on the other end, but it's still really gratifying to have your HB 1 watt signal make a nice hop like that.

QSY

I've noted with quite a bit of interest the recent surge of comments on QRP-L favoring a QRP exodus up from 7030/7040 kHz to [part of] the old Novice watering hole of 7100 to 7125 kHz. The esteemed Arnie Coro, CO2KK seems to have ignited the fire with this post to the reflector:

Dear amigos :
The 40 meters band changed last year ... when the worldwide assignment for ITU Regions I, II and III was finally made totally compatible for the first 200 kiloHertz. According to what we have learned here, this was a difficult to work out agreement, but at the end
thanks to the presence of radio amateurs sitting as members of many of
the nation's delegations attending the ITU WARC... it became a reality...
So, now we have the 7100 to 7200 segment for radio amateurs exclusive use. My understanding is that the US FCC decided to expand the 40 meter phone band down to 7125 kiloHertz...
That leaves the segment from 7100 to 7125 kiloHertz quite useable for CW...
My suggestion is to start using 7105 or 7110 kiloHertz as the QRP
meeting frequency, replacing 7030 and 7040 kiloHertz that are under so much QRM, especially from digital modes. I agree that many stations have already equipment with crystals for either 7030 or
7040 kHz... but for those of us with VFO capability, enjoying the much
more clear channels between 7105 and 7110 kHz opens up the possibility of many more QRM free QSO's...
My observations carried on during the past several days confirm that
that segment of 40 meters right next to 7100 is clear much of the time  !
Let's give it a try !!!

73 and DX
Arnie Coro
CO2KK

The positive response to Arnie's call to action was immensely gratifying to me. In addition to all of the reflector replies, there have also been some ham bloggers taking up the topic. I've long been a fan of this little slice of bandwidth, but at times it has been hard to scare up contacts there. In the last couple of years, SKCC has probably been making the most extensive use of the sub-band, which has increased the traffic there a fair amount and has brought more attention to the frequencies as a place to have a nice, relaxed CW QSO.

Not to long ago, I dreamed about ways to help increase the use of these frequencies, and even started chatting with a few other hams about ways to spark some interest. However, like a whole lot of my ideas, they never get off the launchpad since I just don't have the time to invest in all of them. After having a few unpleasant encounters with RTTY contesters running me off 40 meter frequencies last weekend, I'm even more determined to help promote 7100-7125 as a QRP (and general CW) safe spot.

I've become inspired enough that I've decided to take a new design for a minimalistic superhet rig that I'm working on and adapt it to operate on these frequencies. If there's any interest in it, I might even take a crack at offering it as a kit for purchase. Long live 40 meter QRP!

Over the North Pole

This weekend, I've been participating in the SKCC Weekend Sprint when I get the opportunity in between other obligations. At about 0900 local, I heard F6HKA on 20 meters coming in pretty well with a very fluttery signal. As you can see on the azimuth map for my QTH, the path to France goes right over Greenland, so it's not a huge stretch to assume that the unique signal quality is due to auroral effects from the increasingly active Sun.

After about an hour of trying, I finally managed to snag a QSO with Bert using 5 watts! A great day for QRP!

F6HKA-1811-14-Feb-2010-14046.mp3

Take a listen to this QSO which was recorded a bit before I made my contact with F6HKA. You can definitely hear the watery, fluttery sound of his signal.

Important Willamette Update

Thanks to some prompting from a Willamette builder who inquired about some performance issues with his rig, I was able to identify an error in the bill of materials which causes a significant degradation in receiver sensitivity.

Fortunately the fix for this problem is very simple. Audio preamplifier collector resistor R49 was incorrectly called out as 10 k, when it should have been listed as 4.7 k. If you have a 4.7 k resistor in your junkbox, just swap it in at the R49 position. A 5.6 k resistor will also work fine here. Alternately, you could just parallel another 10 k resistor across the existing one. I will be happy to supply the correct resistor to any builders who purchased a kit from me and need one.

I've determined that this wasn't a design flaw, but a transcription error. My original hand-written notes have the correct value and my prototype does work correctly (I'm sure NA5N would have caught this problem in the prototype he evaluated). Somewhere in the process of creating the schematics in my schematic capture program, I entered the wrong value. I did build a beta rig with all of the same schematics/BOM that everyone else did, but I didn't catch the error at the time. I will update the schematics and BOM posted on my website in short order to prevent any further problems.

Please accept a most humble apology from me for not realizing this significant error for a very long time. I do believe that you'll be pleased with the difference in sensitivity once you install the correct resistor. The receiver should sound like you would expect a proper direct conversion receiver to sound. After the modification, you should be able to run the AF gain at ~75% or less during most operating conditions.

I'd like to thank W0EP, N1RX, WB8ICN, and WB9VTB for their assistance in resolving this matter!

QRP SSB Transceiver in Progress

A little while ago, I got a hankering to work on a SSB transceiver. It's something that I've never homebrewed before, and it seemed it like it might be fun to tackle. The BITX20 seemed like an obvious choice, and W7ZOI recently published an improved bidirectional amp which would be nice to try in the rig. But I'm one who likes to try stuff that's a bit off the beaten path, so I decided to try my hand at something a bit different.

VU2PEP has a lesser-known SSB design on his website, that's a dual-band transceiver. Besides having 20 and 40 meter capability, it also has a different topology than the BITX series. Instead of reversing the flow of the signal to generate a SSB signal, this design sends the RX and TX signal in the same direction through the IF. Take a look at the schematics to get an idea of what I'm talking about.

I decided to make a "remix" of this design. The basic topology is the same, but most of the circuits are revised. The IF was moved to 4.9152 MHz, and the VFO is heterodyne-style to provide a ~19.12 MHz LO signal. My version is only for 20 meters. The front end has a preamp added and uses a cascode JFET mixer instead of a single JFET. So far, the RX strip and VFO is complete (although I might change the VFO because of some birdie problems), but the transmit amplifiers haven't been built yet. I got a good chance to work out the RX during Sweepstakes. Check out my YouTube video below to hear me describe the circuit so far and listen to the receiver on SS.