Last updated April 8, 2008
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Hamfest Schedule
| I've been a licensed amateur
radio
operator for over ten years.
Some of my favorite activities include contesting and antenna
construction. Field Day with W4DW is a perennial favorite
activity. If you made a contact on 80 phone with W4DW this year,
I was probably the voice on the other end. ;-) I have a pretty standard station with a Yaesu FT-1000MP for HF, an Icom 970-H for VHF/UHF and the obligatory Icom 706-MkIIG in the car. Antennas are never a constant around here, but I'm currently running an inverted vee trap dipole for 160 - 20 meters, (well, I was for a while, see below) and trying to decide what to do for 20 thru 10. House remodeling is causing me to keep changing the station, but I'll survive. Like every ham, I've accumulated a lot of gear over the years. What's different is that I acquired a stockpile of new in the box accessories a few years ago. If you need something, check out the list at this link Sort of a Blog! April 8, 2008 Antennas, trimmer capacitors, hamfests, remodels and software. Oh My! Remodeling, Anyone that knows me is aware that I'm remodeling the house with plans to reolcate sometime soon. The work is taking forever though, and the budget is usually half of what actually gets spent. What does it have to do with ham radio? Well, I've saved the family room/kitchen for last. That also happens to be the ham shack. Like so many other shacks in the world, I've had to relocate the shack to the basement. I'm also about to have to move the entry point for my coax so that I can get the deck replaced. Oh joy! On the other hand, it's forcing me to sell off or trash all of the "treasures" that I don't really need at the QTH. At the same time, I'm finding things that I've been searching for months to find! That's a good indicator of "TOO MUCH STUFF!" Antennas, On the antenna front, I've been futzing with various wire antennas. I had a B&W trap dipole for 160 through 20 at about 75 feet for a while. My totally subjective opinion was that it was good on 20 and 40, but marginal on 80. The bandwidth was really narrow, around 100 kHz?, probably a lot less. And it could have been my installation, so take this with a grain of salt. Anyways, I was tired of having to manually retune every time I traversed the band. On a lark, I decided I needed a seperate antenna for 80 phone. Quick and dirty, I dug around a bit and came up with the parts - a couple dog bone insulators, one of those green dipole centers with the molded in SO239, a spool of 5000 feet of copper wire (big *(#^ eatin' grin ) that I acquired just for making antennas, and one of the handiest tools I have for the job - a Hykon wire measure and spooler. (Every wire dealer you ever see at a hamfest has one. They're perfect for spooling off wire for long wire antennas!) A soldering gun and an hour later, I had a dipole cut for 80 phone. (okay, 75 phone - nyah!) Antenna in hand, the next question was where to put it? Having over an acre on a ridge line and in 90 ft. oak trees all around makes this an easy decision - sort of. Quick and dirty strikes again! I lowered the B&W down - it's center supported on a pulley as an inverted vee , with the ends still 20 ft or more above ground -- and attached the new antenna to the same support rope about two feet higher. Basically, the 80 meter dipole (no traps) installed as another inverted vee was directly above the B&W. I didn't think they'd interact very much, but boy, was I surprised! The 80 dipole was 3:1 or better across almost the entire band! Bandwidth on the B&W improved slightly, but not much. Now, to be honest, I don't know if the monoband dipole would have been this broad banded if installed alone or not, but I wasn't in the mood to mess with it. Signal reports were good to excellent, compared to previous incarnations of antennas, so it seemed like a winner. Nothing lasts forever. In this case, it didn't last long at all. Seemed like I was getting some signals from on high. First, the center support rope broke. Then a windstorm brought the antennas down again. Finally, a B&W 90 ft. folded dipole became available at a local radio club auction. This is the one that is supposed to have a 3:1 or better SWR from 1.6 to 30 MHz and above. Sounds like just what I wanted. I needed something better on 160 and I wanted something that the radio could tune internally. It came home with me ;-) and went up a few days later. It's now at about 75 ft., but I'm not convinced it has the performance I want. It seems like a compromise on performance, although it does provide a beautiful match on every band! (But then, so does a dummy load. Hmmmmm....) Oh well, I still have an antenna in the air and a radio that works. When the mood strikes again, I'll try something else. Trimmer Capacitors, (or does your Icom 970H have a display with just dashes where the frequency should be displayed?) New project - my Icom 970H all mode developed a little problem! The 440 side wouldn't display the frequency. Oh, it would while I was turning the big round knob, but once I stopped, after a few seconds, the display just switched over to dashes. After an internet search and a session with the service manual and a volt meter, I found the problem. In the PLL circuit, there's a low locking voltage that needs to maintain at about 1 volt at the test frequency. It dropped to about 0.5. Simple adjust, turn C23 till it gets to 1 volt. Easy fix, sort of. The cap was really, really sensitive! the slightest touch would move the voltage +/- 50%! Tapping the cabinet would even alter the tuning! Bad cap? Probably, but I tuned it as much as I could and buttoned it up and it worked like a charm..... ..... for three days! More digging. Internet search.... one or two articles 'translated' from foreign languages, with missing information.... a couple calls to Icom tech support and a little luck catching the right techs, and I think I have a solution. The wisdom is that there are two trimmer caps that need to be replaced, C23 and C121. The interesting thing is that Icom has changed the part number for C121. Aparrently, they figured out that the original needed an update? Just a guess. The new part is a 12pF CERAMIC trimmer. I think C23 is a ceramic too, but not sure. Anyways, Icom service suggested that both of these caps need to be replaced. In fact, they suggested doing it for both the PLL-A (2 meter) and PLL-B (70 cm) units. Take note: THIS IS NOT IN THE ICOM KNOWLEDGE BASE! There are only a couple (perhaps only one) reference to this problem on the internet. (I found a few references, but they all seem to be copies of the same one.) Although I have the PLL-B problem temporarily fixed again, I ordered the parts so that I could make the fix permanent. I'll let you know how it works. To be honest, this was a team effort with another ham, but I didn't want to publish his call without letting him know first. ;-) Here are the part numbers to order - two each for the radio. C23 4610000110 C121 4610001990 NOTE: THIS IS A NEW PART NUMBER and replaces the original. Software I really need to find some blogging software if I'm going to do this much more! Next, I need to either find or write a logging program. I've been looking but haven't really found something that makes me happy. Since I'm also a database consultant, it should be something I can do! One more project to add to the list! And Hamfests! Can't wait for RARSFest! This Saturday! I've been doing the hamfest thing for a few years now! They're fun, but they're starting to feel more like a job than a fun, leisure activity! Can't wait till I can go to these things to find stuff instead of selling! Oh My! See you at RARSFest! ;-) 73, AG4XR |
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Hamfests are a big part of my
hobby
too. I set up at most hamfests in North Carolina, and a few out of
state. Hopefully though, I'll sell off all my extras pretty soon. While
hamfests are fun, I miss the days when I just went to buy stuff!
Here are my current plans: |