The article “Filter showdown” from DSP DesignLinepresents three filter battles: digital vs. analog, windowed-sinc vs. Chebyshev, and moving average vs. single pole.
Archives for September 2007
This Weekend in Ham Radio at KB6NU
30m was open to the west coast this weekend, and I managed to work several stations out west. One of them was K6XG. We discovered that we had several things in common—he worked for Hewlett-Packard, back when they were in the test equipment business, and I covered HP for Test&Measurement World back then; we both teach General Class license courses; and we both use Begali paddles.
Today, I drove down to the Findlay Hamfest with Zoltan, KD8ABX and George, K8GEO. The weather was really atrocious, but even so, there was a decent turnout, as well as some good deals to be had.
Zoltan, for example, got a double set of fiberglass poles for $80. I purchased another IC-735, this one with an AH-4 antenna tuner for $300. I also got some single-sided PCB stock for $2. I forget which project I was going to use it for, but when I do remember, I’ll be sure to have some on hand.
One amusing thing we came across there was a couple fo vacuum tube-based kits from Glenn, NN8G, whose company is called Pastime Projects. He’s selling a single-tube (6V6) transmitter kit for $64, including the tube, $54 without the tube. Neither kit includes a power supply.
They’re cute, but a little pricey. The one-tube transmitter that I’ve written about would be much cheaper to build, I think.
This evening, I worked Rick, KB1PJO. Rick mentioned that he’d just gotten his license, so I looked him up on QRZ.Com. Sure enough, his license was issued on August 22, 2007, meaning he’s only been a ham for two and a half weeks! He’s the first no-code Tech that I’ve worked on CW, I believe. Let’s keep our ears out for more of them, and when you do work them, please be courteous and patient.
It Pays to Be Persistent…….or Lucky
Yesterday, I wandered down to the shack about 2100Z, thinking that I’d make a couple of contacts while waiting for my XYL to get home from work. I switched the rig to 30m and was instantly thrown into the middle of a pileup. I pulled up DXWatch on my laptop and discovered that the DX everyone was chasing was 3B7C, the DXpedition to St. Brandon Island in the Indian Ocean. The pileup stretched from 10.104 to at least 10.107 MHz.
I tried for more than an hour to crack that pileup. I changed frequencies, I tuned around and found who he was working and tried to call around that frequency, but nothing. After a while, I just got bored and gave up, switching to 40m, where I had a couple of nice QSOs with Jack, W4SON/M and Mark, VA3UMP. (I’m still not sure whether I can count VA3UMP as a callsign that spells a word. What do you think?)
After those two contacts, I decided to give 3B7C one more try. I tuned around a bit, and found that he was listening around 10.106. I heard him sign “TU 3B7C UP” and then hit the button on my memory keyer that blasted out my call. “KB6NU?” was the reply. I reached for the paddles and sent “DE KB6NU KB6NU K.” He came back, “KB6NU 599.” To which, I replied, “TU 599.”
How about that? After an hour with no luck, I worked him on the first call on my second attempt. Yesterday, at least, it was better to be lucky than persistent.
FCC to Lower Vanity Call Sign Fees September 17
I don’t thin that a lot of you have been waiting for the price to go down, but if so……….Dan
From the ARRL Letter, 9/7/07:
The FCC will reduce the regulatory fee to obtain or renew an Amateur
Radio vanity call sign by more than 40 percent starting September 17. In
a Report & Order (R&O) released August 6, “Assessment and Collection of
Regulatory Fees for Fiscal Year 2007,” in MD Docket 07-81, the
Commission will cut the fee from its current $20.80 to $11.70. This
marks the lowest fee in the history of the current vanity call sign
program. The FCC is authorized by the Communications Act of 1934 (as
amended) to collect vanity call sign fees to recover the costs
associated with that program. The vanity call sign fee has fluctuated
over the 11 years of the current program — from a low of $12 to a high
of $50. The FCC says it anticipates some 14,700 Amateur Radio vanity
call sign “payment units” or applications during the next fiscal year,
collecting $171,990 in fees from the program.The vanity call sign regulatory fee is payable not only when applying
for a new vanity call sign, but also upon renewing a vanity call sign
for a new term. The first vanity call sign licenses issued under the
current Amateur Radio vanity call sign program that began in 1996 came
up for renewal last year. Call signs issued prior to 1996 are not
considered vanity call signs, even if the holder was able to request a
specific call sign.Amateur Radio licensees may file for renewal only within 90 days of
their license expiration date. All radio amateurs must have an FCC
Registration Number (FRN) before filing any application with the
Commission. Applicants can obtain an FRN by going to the ULS
and clicking on the “New Users Register”
link. You must supply your Social Security Number to obtain an FRN.The ARRL VEC will process license renewals for vanity call sign holders
for a modest fee. The service is available to ARRL members and
nonmembers, although League members pay less. Routine, non-vanity
renewals continue to be free for ARRL members. Trustees of club stations
with vanity call signs may renew either via the ULS or through a Club
Station Call Sign Administrator, such as ARRL VEC.
License application and renewal information and links to the required
forms are available on the ARRL Amateur Application Filing FAQ Web page. The FCC’s forms page also offers
the required forms.
2007 Simulated Emergency Test, 10/6-7, 2007
From the ARRL website:
The ARRL Simulated Emergency Test is a nationwide exercise in emergency communications, administered by ARRL Field Organization Leaders including Emergency Coordinators, District Emergency Coordinators, Section Emergency Coordinators and Net Managers. Many other Section Leaders like the Section Manager and the Section Traffic Manager may have a hand in planning the exercises and/or reviewing the results. Amateur Radio Emergency Service (ARES), National Traffic System (NTS), Radio Amateur Civil Emergency Service (RACES) and other public-service oriented groups can be involved. The SET weekend gives communicators the opportunity to focus on the emergency-communications capability within your community while interacting with NTS nets. Although the main SET weekend this year is October 6 -7, local and section-wide exercises may be held throughout the fall season.
To participate in this year’s emergency test, contact your local ARRL emergency coordinator or net manager to find out the details for your area. ARRL Sections, ARES teams and nets may conduct their exercises anytime during September through December. If you don’t know who to call, please touch base with your ARRL Section Manager for assistance.
Unstick Coax-Seal
The September 5, 2007 ARRL Contester’s Rate Sheet has the following tip:
To remove stuck-on Coax-Seal from connectors and cables, Carl KM1H recommends Brake Clean if you’re working on the tower. On the ground, use Lacquer Thinner or Acetone which are harder to use aloft. Steve K7LXC also notes that professional grade vapor wraps leave much less residue than Coax-Seal.
Want to Get Your Community Involved in Amateur Radio? Get Involved in Your Community!
I often hear hams lament that their communities show little interest in amateur radio. While this may be true, these hams have to realize that community involvement is a two-way street. To get communities involved in amateur radio, amateur radio needs to be involved with the community.
I’ll give you an example of what I’m talking about. Here in Ann Arbor, MI our amateur radio club worked with the local Red Cross and maintained a station there in the 1980s and early 1990s. For reasons too complicated to get into here, this partnership was severed in the late 1990s.
Even so, we often talked about what we’d have to do to re-establish the mutually beneficial relationship that we once had. Unfortunately, we really didn’t know who to talk to at the Red Cross, and the attempts we made to try to get back in their good graces were fruitless.
That is until I joined the Ann Arbor Rotary Club in March 2006. It just so happened that one of the guys that joined the club at the same time I did was the Chairman of the Board of Directors of the Red Cross. Not only that, but he was very interested in re-establishing an amateur radio capability at the local chapter.
The result is that our club is now working with them again. We have helped them install their 47 MHz radios at the chapter headquarters and in their emergency response vehicles. Having finished that project, we are now in the process of setting up the amateur radio station. While we may have eventually been successful without the contact I made at the Rotary Club, my guess is that this contact greatly accelerated the effort.
Another example is our work with the Ann Arbor Hands-On Museum. This is a science museum that gives kids (and adults, too) some real, hands-on experience with science and technology. There are, for example, exhibits that help kids learn about electricity, springs, weather, electricity, and other topics in science and technology.
When the executive director of the museum spoke to our Rotary Club, the thought occurred to me that this would be a great place for an amateur radio station. I met with the director, who is also a Rotary Club member, and he was very enthusiastic about the possibilities. The result is that we are going to be operating a series of special events throughout the fall of this year, with a goal of setting up a permanent station at the museum in 2008.
I’m sure that my involvement with the Rotary Club was a big part of the enthusiastic reception they gave me and amateur radio. Membership in the Rotary Club, and other community service clubs, such as Kiwanis or the Optimists, give one, if not instant credibility, at least some measure of it. So, my advice is that if you want to get your community involved in amateur radio, perhaps you should first get involved with your community, and one way to do that is to join a service club.
From “Zero to Homebrew”
While cleaning out my e-mail inbox this morning, I came across this recommendation from Kendrick, KB1NCR:
This book made it possible for me to go from “zero to homebrew.”
Frank K0IYE Harris’ book Crystal Sets to Sideband It’s available as a seres of PDF files; each chapter must be downloaded separately.
All of his radios are homebrewed with “no ICs” – this is Frank’s way of
teaching how each stage and circuit work in a straight forward and
comprehensive way.
This is a really good book. It’s packed with lots of good info and practical advice. I plan to recommend it to my General Class students this January.