Come join the DARC for the Mar 2023 Lecture and Lab – In this lab you will solder/build a QRP portable EFHW antenna kit. The build will be at the Dallas Medical Center on the 3rd floor. Plan on attending in-person Mar 25, 2023 start time is 10am central time. More details below
Come join the DARC for October 2022 Lecture and Lab – you will build a vertical J-Pole Antenna for 146 and 455 MHz. Rollin Gary WA5RFG will be leading this build. This will be a fun in-person outdoor event at TW Richardson Grove Pavilion in Irving just off Interstate 635 and part of the Tech-Net in the park later that afternoon. Plan on attending in-person Oct 22, 2022 start time is 10am central time for the antenna build. Details below
The August, 2022, Lecture and Lab will be held in-person at the Dallas Medical Center on Saturday, August 27th, at 10:00 am. We’ll have an antenna build and a presentation, too. The antenna we build will be a 137-MHz helicoidal loop antenna pair for receiving weather satellite images and aircraft radio voice transmissions. The presentation will discuss the best software tools for decoding satellite imagery for yourself. The antenna will be very easy to build, and the cost will be only $30.00. 20 kits will be available!
You’ll need to bring a soldering iron and some general hand tools such as a tape measure, a sharpie, and your favorite set of files. The club will provide the antenna parts, but not the receiver: you’ll want to have a device that can receive signals at about 137 MHz. Most ham radios can’t do that, so now’s the time to check on your scanner or even order an RTL-SDR dongle or one of its competitors like an Airspy or SDR-Play. You’ll also want an adapter from a PL-259 connector to whatever connector your receiver uses.
The planned repeater maintenance on the DARC W5FC 146.880mhz repeater was completed ahead of schedule on March 20, 2022. Work was finished by 11am and the repeater is back on the air and 100% operational. The new Tesco DB224 antenna and coax should resolve all the scratch and noise on the repeater. Big thanks to all that helped to make this a success. Questions of comments hit us up on the contact form and let us know how it sounds and works. More photos from the install gallery here.
Planned Outage – The DARC W5FC 146.880mhz repeater will be off the air for some maintenance and a new antenna Sunday March 20, 2022 from around 8:30am until 2pm Central Time. The new Tesco DB224 antenna and coax should resolve all the scratch and noise on the repeater, please plan accordingly.
These are the easy-to-build cores of the 1:1 balun and 1:49 transformer you’ll be assembling.
Join the DARC for Lecture and Lab August 28th, 2021 from 11am until 2 pm Central Time virtually via Google Meet. (The virtual meeting ID/Link is always on the W5FC event calendar) You will get to build two easy kits: a 1:1 choke balun and a 49:1 impedance transformer. Both will be enclosed in waterproof PVC enclosures and neither kit will require precision soldering. The balun will be constructed to hang below the center of your dipole, and the transformer will be set up for use at one end of an end-fed half-wave antenna. To pick up your kit, you will need to come to the front parking lot of the Dallas Medical Center on August 21st, 2021 from 10:30 – 11:30 to pick up your kit from the Dallas Medical Center parking lot from Tony, NT5TM.
N. T. “Len” Carlson, K4IWL was a long-time DARC member before he retired to Florida, and his article about his favorite multi-band antenna was a popular page on our old website. I’ve looked in the club archives and found his paper for your reading—and on-air—pleasure.
Multi-band antennas can be very tricky to build and tune, but if you put in the effort required to adjust them, you can have a lot of fun.
During the July 2020 DARC Board Meeting, the issue of noise on the DARC 146.880 repeater was discussed. Tony NT5TM did a street level inspection July 10, 2020 and noted NO issues or apparent damage to any of the antennas. A plan was formulated for an early repeater site inspection Sunday July 12, 2020.
The response and interest in my presentation was great! Here are the links from the presentation and the details of my antenna build. Remember, we’ll be building this antenna at the July 28th, 2018, Lecture and Lab.
If you want to reproduce my design exactly, use CQ-118 from The Wireman.
I wanted full 2-meter band coverage; I used a 19 11/16” (498mm) upper section and a 19 3/4” (500mm) lower section instead. His size will work better in a radome, if you want to weatherproof the antenna.
If you attended today’s Lecture and Lab, I hope you had fun! If you need a copy of Budd’s original Buddipole plans, you can find them here. My add-on page of changes is available in this file. Some of you also had questions about the choke balun that I use. You can find more information in this “RFI-HAM” document; I followed the bifilar choke instructions on page 37. [Edit in 2020: the information about the “radio doughnut” chokes has been moved to a separate choke cookbook.]
Our next club meeting will be on September 5th. NWS radar expert Jason Dunn will present on “Reading Weather Radar.”
Don’t forget to sign up for Lifewalk! Members, check your email! The DARC will be supporting this charity run/walk on Sunday, October 1st. Club members have received sign-up links in their email. Non-members who’d like to help should send us a message using the contact form.
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