Ok, this is slightly misleading but it’s true. I had a QSO with a Canadian station over 200 miles away on 2 meters. From my car none the less!
You may wonder how this was done. I had some help from above that’s how. I discovered that on the International Space Station (ISS) is this cool thing called a digipeater. Now I’m no pro at this but I will attempt to explain in hopes that someone else can enjoy getting their toes wet in Amateur Satellite opportunities.
To start, here is an eQSL card of my from my first QSO of this nature:
Note the mode on this card. It’s packet. The digipeater on the ISS relays APRS messages. This was all foreign to me prior to this contact. I discovered all of this by accident while I was monitoring the ISS frequencies for voice and SSTV. APRS transmissions were pouring out of my radio. Curiosity got me to research the sounds and ultimately steered me towards giving it a go.
Although I already had all the parts and pieces to start my way I lacked the knowledge of what to do. It took some figuring out, but I now have a simple and relatively low-cost way of working some satellites. Unlike voice mode, you do not need a directional antenna to do packet through the ISS. I use my mobile radio in my car, an omnidirectional antenna, a USB SignaLink sound card and an inexpensive Windows tablet pc. I downloaded UISS and AGW packet engine (both are free). I think I blew a brain fuse or two figuring out how it all goes together, but in the end, it works.
The uplink and downlink frequency for this is the same: 145.825
Go ahead, tune in and listen while the ISS is over your location. There are many websites and smart phone apps to give you the pass schedule.
If you are interested in this and want help getting started on this for yourself then feel free to shoot me an e-mail [email protected]
On Saturday, June 18th as I was heading home from a workshop I presented in Portland, ME I heard a CQ from KB1RJD on the VHF National Calling Frequency (146.520) for Summits on the Air from Mount Washington in New Hampshire – over 100 miles away. I answered their call but they could not get the last letter of my call sign, so I could not log the QSO. After getting home I looked up more information on Summits on the Air. Abby and I both love to hike and be outdoors and of course combining that with ham radio sounded like a lot of fun and didn’t seem to take any more equipment than what I already have – plus I had just purchased a new VHF/UHF 5 element, Elk Yagi.
Sunday morning, Abby (KC1FFX) and I headed up to Pack Monadnock (W1/HA-041). It wasn’t too far away and we thought it would be a great first try for an activation. If nothing else we would enjoy some beautiful weather on Father’s Day together! We jumped in the car with the ELK Yagi and a 5 watt HT on battery power. We also brought my IC-7100 and a buddipole. Let me tell you, we had a blast! We had so much fun on 2 meters with the handheld that we never got to setting up the buddipole.
It was a gorgeous weather and we made 12 contacts as far away as Plymouth, MA and Madison, NH! We really enjoyed the directional antenna and trying to “home” in on signals – we seemed to get better as the day went on.
We’re already looking forward to our next SOTA activation. When we got home we started looking at all the other mountains and hills in the area. There is a list of summits here.
We would love to hear from others that have tried SOTA before or if anyone would like to team up and activate a summit!
The most important piece of equipment in ham radio is our antenna. We are connected to the world with the magic of radio waves! Each License Exam from Technician through Extra class has questions to test our knowledge on antenna design and building skills. Home-brewed antennas are easy and relatively inexpensive projects.
This article describes a 2m, 3-element Yagi antenna construction concept that the N1FD FCC license teaching team has used over the last year for class demonstrations. The “Lego” style construction (v. 2.0) shown in the above picture is our new design that demonstrates the operating principles of the ubiquitous basic dipole antenna as well as a 2-meter, 3 element Yagi. (Note, This project evolved from an earlier effort by Diana Eng at Makezine.com, which can be seen here.
In this Newsletter issue, we will describe the construction of the “Lego” stylized antenna and show how it can illustrate basic properties of a dipole antenna. We will build a Yagi antenna with the addition of reflector and director arms in a future Newsletter article.
CONSTRUCTION of the LEGO STYLIZED ANTENNA.
The antenna demonstration unit consists of two assemblies.
A handheld receiver dipole set to a fixed frequency (e.g., 146.550 MHz). It is shown at the top of the photo above. It follows a “plumber’s delight” construction using pieces of PVC pipe for a short boom and handles. The dipole arms are two telescoping (7-28 inch) FM radio replacement antennas, available on eBay or Radio Shack ($4-6 dollars). The arms feed through the boom and are epoxied. Bridging across the arms is a common 6-volt flashlight bulb. The bulb lights up when the dipole receives a resonant rf signal.
The “Lego stylized” Yagi antenna components are shown below the receiver unit. The boom (middle item) is made of red oak dimensioned at ¾ x 1 ½ x 48 The top surface is grooved to hold an epoxied 3/16 steel rod. The bottom surface has drilled recesses to fit ¾ in PVC pipe for leg stands. The edge of the boom has two 24-inch adhesive tape rulers running from center to front and back of the boom. The rulers read-out the spacing between the driven dipole element and the parasitic reflector and director arms. In the photo, the D.E. and parasitic elements are seen below the 48 in. boom. The center element is the driven dipole and it is flanked by identical units that can be configured as either reflectors or directors. Each unit consists of two telescoping FM radio antenna rods epoxied in a grooved piece of red oak ( ¾ x 1 ½ x 3 inches) serving as “riders” on the boom. The telescope arms can be adjusted to “resonance” at any frequency in the 2-meter band. The bottom of all riders has 2 x ½ inch rare earth magnets. These allow the three antenna elements to be fixed at any position on the 48 in. boom.
You can view a closer look at the assembled Yagi antenna configuration in this video (Click on Link)
DEMONSTRATIONS OF BASIC DIPOLE BEHAVIOR.
1. Antenna Resonance Determined by Dipole Length.
As we all know, the resonance length of a dipole is given by the equation: L (in inches) = 5616/ [ Frequency (in MHz)]. We can show this fact with aid of the “receiver” antenna, which is set for a frequency of 146.55 MHz The light bulb of this antenna will light when it senses a signal of this value from our “Lego” antenna.
In the video below (Click on Link), we begin with a resonant D.E. length of 38.5 inches and see the receiver antenna light up. Next, we manually shorten the D.E. and see the bulb light dramatically dim. When the D.E. length is returned near the start value, the light bulb again brightens up.
Effect of SWR on Signal Strength.
Most modern transceivers have a built-in auto-tuner that can match SWR up to 3:1. We know this only makes the “radio happy”, still we key down without much thought on how our Tx signal degrades with a 3:1 match. The pictures below use the transmitting “Lego” dipole and receiver dipole to show the received signals for an SWR of 1.1 and 3.0. The SWR was changed by lengthening the D.E. elements by 2 inches while holding the Tx frequency at 146.55 MHz
3. Polarization Effects between Tx and Rx Antennas.
A horizontal dipole shows “horizontal” polarization; meaning the electric field vector of the rf signal is parallel to the earth surface. Similarly, a vertical dipole displays “vertical” polarization with the electric field perpendicular to the earth. We all learn this in a Technician class course.
When we use our 2m HT’s for short distance contacts, Tx and Rx antennas with opposite orientation create a huge signal loss. The effect is shown dramatically in the video below.
Our classroom constructible antenna for demonstrations in our Ham Radio license classes has evolved in design over the past year. We believe it has been a useful resource, helping students translate textbook theory to “Hands On” practice. Perhaps, this review has kindled interest for our readers to think of their Next Antenna Project!
The Nashua Area Radio Club has a dedicated team of Ham Radio license class instructors and we offer Technician, General, and Amateur Extra classes twice a year. We have a great track record using the Gordon West class materials and have 68 graduates who got their initial license or upgrade.
Our classes are held at Dartmouth-Hitchcock Nashua, 2300 Southwood Drive in Nashua.
We setup a live VHF and HF station in the classroom, which allows us to provide live demonstrations of the class material. This helps students to better understand the material and also give them an idea of what they can do with their license once they have it.
This season, two new instructors have joined our team, Greg Fuller, W1TEN and Brian Smiglieski, AB1ZO, who are both graduates of our May 2016 Extra Class. They join our existing instructors Dave, N1RF, Skip K1NKR, Wayne AG1A, Aron W1AKI, Anthony, KC1DXL, Wayne, KB1HYL, Fred, AB1OC and Anita, AB1QB.
More information can be found in the flyers below. Please pass this information along to anyone you know who is interested in a Ham Radio License or an upgrade. Contact Anita, AB1QB at [email protected] to sign up.