Soldering Coax Connectors

What good is a shiny J-pole antenna if you can’t connect it to your radio? It makes a nice sculpture — a “copper cactus” — but it won’t help much with reception. So for our latest SPARC build, the club met at the garage of Bob WB6YJJ to put our soldering skills to the test. Bob and Tim WA0PTC guided us through the process of soldering UHF connectors, also known as PL-259 connectors, to lengths of RG-8X coaxial cable. With some patience and steady hands, everyone went home with new, handmade cables to hook up and get on the air.

Checking the connector

Checking the connector

Soldering it all together

Soldering it all together

PL259 Diagram

How to connect PL-259 connectors to coax cable. Diagram via

2 Meter Copper J-Pole Antenna

After two informative presentations from Allen Wolff  KC7O, first on soldering technique and then on constructing a 2m cooper j-pole antenna, SPARC members held a group build as our October meeting. Bob WB6YJJ generously hosted the eager builders in his garage workshop. The total cost of materials per antenna was only $20. And according to an antenna tuner, each j-pole had an impressive 1.2 : 1 SWR (standing wave ratio). Not bad! (I used my j-pole during our October 11 on-air net and received good signal reports. —ed.)

If you are interested in building your own 2m j-pole, Allen has graciously shared his presentation. Click here or on the image below to download it as a pdf.

If you have any questions about Allen’s design, feel free to reach out to us.

And here are a few pictures taken during the build.

A completed j-pole ready to go on-air.

Sending Data with Fldigi

Fldigi stands for Fast Light Digital modem application. It’s a free and open-source program that allows an ordinary computer’s sound card to be used as a simple data modem. (I’m paraphrasing Wikipedia here!) ARES Northeast has been spreading the word about Fldigi’s usefulness when other communication systems fail due to natural disaster or power outage. You can use it to transfer small files from your computer when the Internet is down.

SPARC’s own Oliver, K6OLI has created a guide to setting up Fldigi on a Windows PC. His step-by-step instructions, complete with screenshots, will get you up and running.

In addition, the following two videos come recommended by ARES NE director Gary Wong, W6GSW. If you are using Fldigi, consider dropping by an ARES activity day to compare notes with fellow SGV hams!

Fldigi: Learn How to Use It

Basic NBEMS Fldigi Setup

Winlink: Email Over Radio

At our January 4, 2017 meeting, SPARC president Bob Vanderwall WB6YJJ presented a video on the benefits of Winlink. Here is a simple definition of Winlink taken from its Wikipedia page:

Winlink is a worldwide radio messaging system that uses amateur-band radio frequencies to provide radio interconnection services that include email with attachments, position reporting, weather bulletins, emergency relief communications, and message relay.

The most common use of Winlink is sending email from an area where the Internet is unavailable. During an emergency that knocks out Internet access, Winlink can get a message to loved ones and other contacts. This powerful communication resource is an all-volunteer effort administered by a group called the Amateur Radio Safety Foundation Inc. Our Northeast section of ARES (Amateur Radio Emergency Service) uses Winlink as part of its preparedness plans.

With a relatively small investment in equipment (typically an external sound card and free software such as Winlink Express), amateur radio operators can get up and running. Over the course of 2017, SPARC will continue to discuss how to set up and use Winlink at our monthly meetings .

This video by Rick Frost K4REF is a great introduction to Winlink. Rick has posted a series of videos on various aspects of the system on his YouTube page.

Once you’re ready to give Winlink a try, here are recommended node frequencies for the San Gabriel Valley:
145.050 MHz, 1200 baud
W6GSW-10 (Alhambra)
KA6ECT-10 (Pasadena)
W6SGB-10 (San Gabriel)

431.125 MHz, 9600 baud: