Teaching Evan the basics of radar signal processing with this baby-block 7-bit Barker code and its matched filter.
Archive for the ‘life’ category
7-bit Barker Code and Matched Filter
January 8th, 2012(No?) Nonsense Radio
November 10th, 2011The November 2011 issue of QST contains an Op-Ed that really left me shaking my head more than normal. The author bemoans the complexity and feature sets of newer handheld radios and pines for the days of his IC-02AT. He goes on at length about the “unnecessary” receive capabilities (NOAA weather broadcasts, AM/FM radio, etc) and how he has to search for the manual every time he wants to program a repeater offset.
Well, as someone who recently upgraded from a radio just slightly newer than the IC-02AT to a “modern” HT, he’s wrong on nearly every account (except the micro-/mini-USB port, which I would wholeheartedly support for charging purposes).
- Eliminate extraneous features. Too bad we all have different definitions of this. I think scanning is a worthless feature, but like NOAA/NWS weather broadcasts. In fact, my wife is delighted that we now have a battery-powered AM/FM+NOAA/NWS radio again that I will always be able to find and will guarantee that it works. Did you hear that, guys? My non-ham wife actually likes my HT and uses it to listen to FM radio!
- Eliminate multilevel menu trees. I’m just dying to replace my cell-phone-sized VX-3r with a knob-covered brick. I’m sure you are too. It’ll look great in my shirt pocket.
- Eliminate the proprietary programming cables. Maybe I’m not a typical ham, but I only have about ten memory channels programmed into my VHF/UHF FM radios and they took about 10 minutes to program through the front panel (my bad, menus). The mini-/micro-USB port is a good idea for charging, though.
- Allow for a battery pack that uses disposable batteries. Last time I checked, most radios have this option. Did I miss something?
- Create an inter-vendor standard for user interface. What if they standardize on Icom?!?! The last Icom VHF/UHF FM radio I used received a “grade of S, for ‘stupid’” from its owner. That was in 1993. All of the Japanese manufacturers will be put out of business by the factory owned by the Chinese military that produces their products before this happens.
He should buy another IC-02AT if he liked them so much. I bet for a Jackson or two, you could have a nice one…complete with the 6x AA battery holder. Heck, buy two or three for spare parts. I think I have the Service Manual around here somewhere if I didn’t already sell it.
On a more serious note, there are lots of no-frills radios available out there, even brand new ones with factory warranties. Until recently, at least, the money in VHF FM radios was in two-way, government, and public safety, not amateur. There are a lot of amateur rigs at the “low end” of the market that share a lot in common with their commercial counterparts. And, of course, you can always buy used Motorola gear on eBay if you desire ultimate performance and ruggedness.
DXpedition QSLing
November 1st, 2011This post might better be titled “supporting things that you value.” A recent large-scale DXpedition to a “new one” just started sending out QSL cards in the past few weeks. I have seen a bit of traffic leaking onto the regional contest club’s e-mail reflector about QSLing this operation and today someone complained that QSL requests that included donations were being processed rapidly and that he had not yet seen his. He was thoroughly chastised by a number of people on the reflector (including one of the DXpedition operators who went on at some length about the cost of the DXpedition) before the thread was (wisely) quashed by the moderator.
I composed a short reply very early in the melee, but decided (also wisely) not to contribute it because it really had little to do with contesting. So, I’m writing here in hopes that someone finds it interesting.
When I was a new ham, I won a copy of the ARRL Operating Manual at a hamfest. It sounds inane now, but I read the thing cover to cover. In the chapter on DXpeditions, the author writes, “A donation should never be a condition for receiving a QSL card.” That has stuck with me through the years. The fundamental question is: why spend tens of thousands of dollars on the effort only to hold the operators who worked you hostage for a donation that might cover your QSLing costs if you’re lucky?
But, life is rarely black and white and most DXpeditions understand the futility of that question, so the situation outlined above rarely happens. In the present scenario, the DXpedition stepped into the gray by prioritizing donors ahead of non-donors. I have no problem with this. In fact, as I began to write in my reply, it is a matter of supporting things that are important to you. If having a card for the “new one” is important so you get on the Honor Roll for this year’s DXCC Yearbook, how much is that worth?
This falls into the same category as people who used to complain about the results of contests sponsored by CQ magazine being unavailable for free online. Well, if you want the results, buy the magazine!
Enough ranting…did somebody mention that CW Sweepstakes is this weekend? SWEEPSTAKES!
New Arrival
July 10th, 2011
Early Monday morning, the day after Field Day, we welcomed our son Evan into the family. We were so right to stay home! As good friends have opined “your life will change…for the better.” So far, I would tend to agree. The blog will receive (even more) infrequent updates, K8GU may be a little less active on the air, and there will be fewer homebrew projects over the next few weeks and months. A few months ago after building some UHF antennas when I pinched the palm of my hand with a pair of pliers, I watched the blood blister heal and commented to Sarah on how amazing it was for several days straight. “You think that’s amazing? Well, I’m growing new life inside of me.” We laughed, but it’s very true. Every day is something new: grasping, gazing, grunting, and gurgling. This is only the beginning. That’s pretty amazing.
The Rupture 2011
May 22nd, 2011Thanks to some quick thinking on Sarah’s part, I was able to attend the Hamvention (Saturday only—the day that the sewer backed-up and “ruptured”…spewing nasty water down through the fleamarket) for the first time in a few years. This is a recap from my perspective.
- Attendance was down. The fleamarket was shrinking.
- There were a lot of lookers but few buyers in the fleamarket. Predict that the fleamarket will shrink further next year.
- There were still good deals to be found in the fleamarket—I picked up some LMR-600, a WA2AAU 2304-MHz amp (unmodified 1900-MHz PCS amp), a Rohn 45G rotator plate, some 20-GHz rated SMA relays, and some miscellaneous parts. And, I passed on a few good deals as well.
- I saw a lot more young people than I remember from past years. Or maybe I’m just getting older and the population of hams younger than me is growing on account of that.
- Hamabouts (and their drivers) were not so obnoxious as prior years.
- Hara Arena may be a dump (K1LT told me the story—don’t know if it’s true—that during the Rolling Stones first U.S. tour, they had been booked at Hara, but refused to play when they saw the facility); but, it’s perfect for the riff-raff who show up for the Hamvention.
- In the end, the Hamvention (like ham radio itself) is about the people you know and meet. I had fabulous eyeball QSOs with guys from almost all phases of my ham career (except the early years from 1993-2000). The VHF/UHF weak signal crowd is a pretty amazing bunch of hams. I had a great time getting to know some of them in the fleamarket.
Great Idea: Light Painting WiFi
March 21st, 2011Saw this in my Google Reader at work and had to post. Apply to work, ham radio, …? It’s clearly an artist’s take and not an engineer’s.
CQ 160 CW
January 31st, 2011We got a dose of Mid-Atlantic winter weather last week—that once or twice a year event that is too much for the utilities and drivers to handle. Snow, sleet, freezing rain, and rain arrived on Wednesday. Power was out from 2030 LT to 0200 LT on Wednesday night/Thursday morning and then again from 1600 LT on Thursday to around 1100 LT on Friday. So, I didn’t get to operate NS this week on account of no power! I did think of going out to the car, but I was too wiped out and cold from the furnace blower being off. I just wanted to crawl under a big pile of blankets and sleep until the electricity came back on. As I have mentioned before, I grew up in an area with many Amish. A coworker many years ago was teasing me about finding an Amish girlfriend. I responded by asking him how an electrical engineer would fare in a society dedicated to not using electricity. He had to agree, although the Amish have rather ingenious mechanisms for harnessing electricity to do their work. But, as usual, I digress—we’re slightly dependent on electricity in ways we probably should not be!
I like contesting on 160 meters (1.8 MHz). When you call CQ, you are usually rewarded with blistering rate from loud stateside stations. When you’re tuning up and down the band, weak DX stations pop out from between said loud stateside stations. Now that I have something resembling a 160-meter antenna, I gave the CQ 160 CW contest a shot after some friends left on Saturday night. Another nice thing was that the station is working well enough (with the exception of the K9AY relays and possibly directivity) that I could just walk into the shack and operate.
So, that’s what I did… Only worked a handful of Europeans, but that’s not too surprising. They were loud here, even with 10 dB of attenuation in line to reduce IMD from really loud local stations. There were numerous other European stations that I could hear (on the TX antenna) but was unable to raise. But, in about four hours (three in the CQ 160 and one in the NAQP) of operating on Topband, I have only the hard states left for WAS from this QTH: ID, SD, ND, WY, AK, HI. I’m waiting for the LoTW confirmations to start showing up!
CQ 160-Meter Contest, CW Call: K8GU Operator(s): K8GU Station: K8GU Class: Single Op LP QTH: MD Operating Time (hrs): 3 Summary: Total: QSOs = 182 State/Prov = 48 Countries = 8 Total Score = 25,984 Club: Potomac Valley Radio Club
Recent tinkerings (9 Jan 2011 edition)
January 9th, 2011Several people have commented over the years that I should “write more” on the blog. I usually respond that I could spend my free time tinkering/hamming or blogging, but not both. Here are a month’s worth of blog posts as freestyle poetry:
- A section on my workshop has been added to k8gu.com under Engineering.
- Discovered that although the SoftRock VHF Ensemble II won’t fit (barely) into the Bud CU-473 diecast box I bought for it, it will fit into an extruded enclosure that housed an ancient X-band radar detector I picked up at Dayton in 2002 in hopes of stripping the Gunn diode assembly and getting on 10 GHz. Bonus points for thriftiness. Photos will follow once I finish the project.
- Did not observe Quadrantid meteor pings with the SoftRock VHF Ensemble II, but did notice something interesting about the W3APL beacon. Need to investigate.
- Have more CE/K8GU QSL cards again, finally. Tonight, I might finish the bureau (and, ashamedly one direct) cards languishing. Some K8GU (and AA8UP, no kidding) bureau cards are sitting here staring at me, too. Not a big project, though.
- Operated the NAQP CW on Saturday (8 January 2011) for four hours and twenty minutes and made 318 QSOs x 128 multipliers for 40,740 points before log-checking discounts. This total is pleasing to me especially considering that it was almost all leap-frogging SO2R search-and-pounce, which can be very fatiguing. It’s fun to see the rate meter stay over 100 when you’re S&Ping. Good Sprint practice.
- Still the best 30 minutes on the radio every week: I operated the NS Ladder on Thursday (6 January) night and made my customary 30 QSOs x 24 multipliers for 720 points. Hopefully, adding 160 will give me some momentum to increase this score back over 1000.
- We had a spell of 50F (10C) weather on New Years’ Eve. So, I put the 2-meter beam back up on the chimney. It was formerly mounted on a steel mast that was ratchet-strapped to the chimney. A strong wind (>50 mph gusts) before Christmas bent the mast (actually a fence top-rail) and I had removed it. I cut the bent lower portion of the mast off and attached the remaining top portion with rotator to a “girder” constructed from two pieces of treated 2″ x 4″ x 10′ lumber joined with a half-dozen lag screws. Again, I ratchet-strapped the entire assembly to the chimney. The present configuration is much stronger and less prone to damage. The 3-element 50-MHz Yagi is still on the ground until I actually get the transverter finished, which should be soon (as it has been for 12 months now).
- Repaired a SoftRock v6.2 downconverter for WF1L and learned that you can solder leads back onto SOIC packages if you’re careful.
- Have had delightful exchanges with KN6X and ZL1CDP about repairing the TS-930S. Some of these discussions (and their fruits) may make it onto the site at some point.
- Back in December, I started integrating the W1GHZ transverters using UT-141 semirigid jumpers with pre-installed SMA connectors obtained on attractive terms from Max-Gain Systems. Mitsubishi RA18H1213G (1296 MHz) and RA30H0608M (50 MHz) modules arrived from RF Parts. May have a lead on something less expensive with more gain for 903 MHz via HA1AG. The big remaining tasks in all three transverter projects are the sequencer and IF interfacing.
- Also in December, I had dinner with NS Ladder father Bill, N6ZFO, in San Francisco at the Hyde Street Seafood House & Raw Bar, which is a favorite of NA Sprint father, Rusty, W6OAT. Yes, I did feel that I was in the presence of greatness. (I had their excellent pork chops since I’m not into seafood, especially raw seafood.) Like most contesters, Bill’s a super, fascinating guy apart from his radio contesting interests.
Locality Bias
January 3rd, 2011
Slate Labs has an “interactive tool” to look at food deserts in the U.S. by county—places where a healthy variety of food is unavailable. They define a metric of desertification by counting the number of people who do not have access (not sure how this is defined) to a car AND live farther than one mile from a supermarket (not sure how this is defined, either). So, I went looking at some places I’ve lived.
My home county is Holmes County, Ohio. If you look at the map, it’s the one that’s an island of dark brown in the middle of Ohio. 27.91 percent of Holmes County is a food desert by this metric! Blame it on the Amish. Because the county is rural, there are few grocery stores. And, because the Amish do not have access to their own cars, they count a large portion of this population. Other counties with large Amish populations (relative to the non-Amish population) also stand out clearly.
It also appears that the map is distorted by population density, with sparsely populated areas being more prone to classification as food deserts. Is this fair? Is there anything that can be reasonably done about these areas even if they are food deserts? I don’t at all disagree that this is an important, significant problem, but it seems that there might have been a better metric. Perhaps it’s the most accessible metric with the available data?
Although this map may be revealing in many ways, it also distorts the reality a bit. For me, it’s a reminder to not consume “news infographics” too casually. I haven’t read all of the comments on the Slate piece and probably won’t. So, forgive me if someone has already noted some of the above. As a final note, most of the people who write for Slate are relatively ignorant of what happens in the part of the country between the Coast Ranges and the Appalachians. So, as one commenter wrote, it’s a “typical urbanite view” of food.
Ruling the Air
November 29th, 2010
I rolled over another year on the odometer of life last week and as is the custom around here, I received some gifts, several of which were radio-related. The shirt is from my wife. The Yamaha CM500 headset is from my parents.
Both of these came in good time since my “CW is the Real Thing” shirt is getting threadbare and my ProSet developed a bad spot in the cable in the past week. I got to try them both out for a brief period at the W8AV multi-two operation in the CQ WW contest over the weekend.
The CM500 (the manufacturer page for these is gone, but you can get them from the usual places) came as highly recommended by the denizens of the Elecraft reflector via the PVRC reflector. They’re pretty good headphones. The sound is good and they have plenty of volume when driven by a TS-930. The ear pads are a little thicker than those on the ProSet, which is good because after a few hours, my ears feel pinched by it. The big downfall of the CM500 is that it feels a little bit like my head is in a vise when I wear them. There may be an adjustment for that.
I was originally thinking that I should send the ProSet back to Heil to be refurbished. But, the price is much higher than I remembered. Fortunately, they stock parts for the old models. So, I will be doing the refurbishing myself.
In WW news, I only operated for about two hours on Sunday afternoon at W8AV. Goose replaced his big tower with a new one and the lower 40-meter antenna was not back up yet. But, with a single 2-element Yagi at 140ish-feet and 1.5 kW from a homebrew 8877, I easily carved out a spot around 7064 kHz at 2000 UT and ran off a nice string of Europeans just as the band was opening.
