Tag Archives: Antennas

Hamvention 2018

On May 16th, Fred, AB1OC and I traveled to Dayton, OH for the annual Hamvention, held at the Greene County Fairgrounds in Xenia, OH for the 2nd year.

Contest University 2018
Contest University 2018

The Hamvention opened on Friday, May 18th, but we attended Contest University, held at the Crowne-Plaza in Dayton on Thursday.  We attended some great presentations there including one on VHF Contesting with JT modes – FT8 and MSK144 by W5ZN,  Joel Harrison and one on Learning from your Log-Checking Report by Doug Grant, K1DG. We also got to hear Rob Sherwood, NC0B, report on transceiver performance.

Anita, AB1QB with Dave, N1RF
Anita, AB1QB with Dave, N1RF

NARS Member Dave Michaels, N1RF  recently moved to Indianapolis, which is not far from Xenia.  Fred and I met up with Dave on Friday at the Hamvention.  It was great to see him again.

Elecraft KX2 Shack in a Box
Elecraft KX2 Shack in a Box

Since our Tech Night show and tell on portable and mountain-topping equipment, I have been interested in the KX2.  Our first stop on Friday was the Elecraft booth where we purchased the KX2 “Shack in a Box” and some accessories to go with it.  I am looking forward to using it during our upcoming SOTA activations to operate using FT8 and other digital modes.

Par Endfedz portable wire antennas
Par Endfedz portable wire antennas

We also purchased some PAR EndfedZ wire antennas from LNR Precision.

Burns Fisher, WB1FJ at the AMSAT Booth
Burns Fisher, WB1FJ at the AMSAT Booth

Next, we visited the AMSAT booth, where we chatted with NARS member, Burns Fisher, WB1FJ.

Dave Jordan, AA4KN, ARISS Mentor
Left to Right, AB1QB, Dave Jordan, AA4KN, ARISS Mentor, and AB1OC

We also met Dave Jordan, AA4KN, who is the ARISS Mentor for the upcoming ISS  Crew Contact with Hudson Memorial School.

Yaesu's newly announced transceiver, the FTdx101D
Yaesu’s newly announced transceiver, the FTdx101D

We saw a few newly announced items while visiting the vendor buildings.  Yaesu announced the FTdx101D.

Kenwood’s new transceiver, the TS-890S

Kenwood announced the TS-890S, which is pictured above.

SteppIR's new SDA-2000 Controller
SteppIR’s new SDA-2000 Controller

We also saw SteppIR’s new controller, the SDA-2000 OptimizIR

Flex Radio Power Genius Amplifier
FlexRadio Power Genius XL Amplifier

We also saw the FlexRadio Power Genius XL 1500 Watt Amplifier, which recently started shipping.

Rotating Mast soon to be available from Buddipole
Rotating Mast System soon to be available from Buddipole

We also visited Chris Drummond, W6HFP from Buddipole and he showed us their new MastWerks Mast/Tripod system.

Information on GOLF Series of Satellites at AMSAT Forum
Information on GOLF Series of Satellites at AMSAT Forum

We attended a few forums at the Hamvention including one from FlexRadio on SDR Technology.  Especially interesting was the AMSAT forum, where we learned about upcoming Satellite launches, including the GOLF Program (to follow the FOX Program).  Satellites in the GOLF program will have higher orbits resulting in larger footprints and also will incorporate new technology.

Overall, we had a great time at the Hamvention and we’re looking forward to going back in 2019!

Anita, AB1QB

Field Day 2018 is Almost Here!

Field Day is an Emergency Communication Preparedness, Communications Training, STEM Learning, and fun activity all rolled up into one event! Field Day 2018 is rapidly approaching and we’ve been working for over a month now to plan our 2018 operation. Field Day at the Nashua Area Radio Society is a major undertaking so we decided to share the Chairperson role among three members:

2018 Field Day Team Leaders
Team Leaders

It takes a great deal of support from our members to put together an operation at the level we do it at NARS. We’ve had many NARS members volunteer as Team Leaders to plan and pull together the many elements of our upcoming Field Day. Many, many thanks to all of our Team Leaders and to everyone who is contributing to support Field Day 2018!

Field Day 2018 Plans & Goals

Our Goals for Field Day 2018
Our Goals

We began our planning by setting some goals for our operation. Field Day at NARS centers around being a learning experience for all involved with a special focus on getting new members, new Hams, and young people on the air.

2018 Field Day Site Layout at Hudson Memorial School
2018 Field Day Site Layout at Hudson Memorial School

Our new site at Hudson Memorial School in Hudson, NH gives us the opportunity to experience Field Day at a new site. Our 2018 operation will double as our Open House for our High-Altitude Balloon program schools.

Space Communications Ground Station
Space Communications Ground Station

It will also provide an opportunity to test the space communications ground station that we are building to support an ISS Crew Contact with the students at Hudson Memorial School in the fall.

Station Plans

High Tech SDR System at Field Day
High Tech SDR System

We always like to incorporate new elements into our setup each year. This year we’ll be increasing the scope of our Software Defined Radio Setup and using it to add more Digital Stations.

Field Day Digital Station
Field Day Digital Station

We are planning a 10 Alpha station for our 2018 operation. With the additional Get On The Air Station (GOTA), free VHF station on 6m and the additional satellite ground station and 2m/70cm GoKit for Talk-in and Messaging use, we will have a total of 14 transmitters on the air at Field Day 2018! Here’s the planned breakdown for station bands and mode:

  • SSB Stations – on 40m, 20m, 15m, and 10m/75m
  • CW Stations – on 40m, 20m, and 15m/10m/75m
  • Digital Stations – on 40m, 20m, and 15m/10m/75m
  • Free VHF Station – on 6m (all modes)
  • Satellite Station – on 2m/70cm/23cm (all modes)
  • GOTA Station – on 15m/10m/75m SSB
  • Talk-in/Messaging Station – on 2m/70cm FM
Field Day SDR-Based GOTA Station
SDR-Based GOTA Station

Our GOTA will also use our Software Defined Radio system and share antennas with the Digital Stations. This approach provides an easy to understand and high-tech view radio equipment and SSB voice operations on the HF bands.

Generator Power at Field Day
Generator Power

We will again be in the Alpha category using off-grid power via generators. We will also have a solar/battery setup that we will use to make some contacts.

Antenna Plans

60 ft Digital Tower
60 ft Digital Tower

Antennas are a large part of any Field Day station and NARS brings a lot of top-notch equipment. We are planning to put up three towers again this year and all three will have yagi antennas for 20m/15m/10m along with wire antennas for 80m and 40m.

40m V-Beam High-Performance Wire Antenna
40m V-Beam High-Performance Wire Antenna

The 40m V-Beam wire antenna will be back for SSB and it has been optimized both electrically and mechanically.

Learning Opportunities

Setting up a Tower at Field Day
Setting up a Tower at Field Day

The setup of our antenna farm is a good example of one of the many learning opportunities at Field Day. Hamilton, K1HMS, and Jamey, AC1DC have been conducting Antenna Parties to give members a chance to learn how to build, setup, and tune our antennas. We’ll also be providing extensive training and information about all aspects of setup and how to operate during our June 5th Membership and June 12th Tech Night Meetings.

Team Operating at Field Day
Team Operating at Field Day

Learning to operate is another important aspect of Field Day. It’s a lot of fun for folks who are new to Field Day or to a particular operating mode such as CW or Digital to team up with a more experienced operator to operate as a Team. Doing this for your first hour of operating time will help you get up to speed on how to use a station to operate. You can also help out the more experienced operator by helping to capture call signs and exchanges and to log contacts.

Food, Fun, and Videotape at Field Day…

A Feast at Field Day
A Feast at Field Day

Valerie Merchant has again volunteered to provide food for us during our operation. Valerie did a great job with this last year and we are very happy to have her do this again this year. THANK YOU, Valerie!

WK1V's Video Drone
WK1V’s Video Drone

Also, Desmond WK1V will be bringing his drone again this year. Desmond took some amazing aerial video of our 2017 operation. Check out the video which follows.

Our 2017 Field Day Highlights Video

Important: Sign Up & Don’t Miss These Meetings

Our Field Day sign-up for Station Setup/Takedown, Operating, and Meals is available in our Members Forum on n1fd.org (don’t forget to log in to our website to view this link). Take a minute to follow the previous link and sign-up to be part of Field Day 2018! If you are not a member or are having trouble accessing the sign-up, please contact us at [email protected] and we’ll answer your questions and help you to sign up.

Field Day Station Training
Field Day Station Elements and Training

Also, we’d like to see as many members as possible attend our June 5th Membership and June 12th Tech Night Meetings. We will be sharing lots of information and how-to material and training between these two meeting. Please try to attend both to learn and take full advantage of the fun at Field Day. You don’t have to be an old hand or even have ever participated in Field Day before to have a lot of fun. Just try to make it out to these meeting and we’ll get you up to speed and help you to participate!

Bring Your Family & Invite Your Friends

Field Day Public Info Tent
Public Info Tent – Videos, Information, and a Talk-in/Messaging Station

Field Day is also a great opportunity to showcase Amateur Radio to the general public. We set up and staff a Public Information tent as a starting point for visitors to learn about the Nashua Area Radio Society and what we are doing on-site. We will provide tours of the site, a chance to Get On The Air at our GOTA station, demos of the equipment we are using, and much more! Please bring your family and invite your friends to come out to Hudson Memorial School in Hudson, NH any time between 2 pm Saturday, June 23rd and 2 pm Sunday, June 24th and visit our site. Here are some direction to our site (click below or refresh your browser if you don’t see the map) –

 

See you at Field Day 2018!!

Fred, AB1OC

A 40m High Performance Antenna for Field Day

The Nashua Area Radio Society has been using a 3-element 40m wire beam antenna for Field Day for the last several years. The antenna uses three guyed 50 ft. fiberglass masts from Max-Gain Systems. The antenna uses three inverted-V style elements separated by a little over 50 ft. Since we are in the northeastern United States, we can point the antenna on a fixed, 260° heading and it covers the entire U.S. well.

40m V-Beam EZNEC Antenna View - Antenna Optimization
40m V-Beam – EZNEC Antenna View

Our 40m V-Beam antenna was initially designed using EZNEC 5.0. It was manually optimized for decent gain and front to back performance and it worked quite well. Recently, we decided to try automatic optimization software on the antenna as part of a tune-up on the design for Field Day 2018. After looking around on the Internet a bit, we discovered a software package called AutoEZ which looked ideal the my project. You can read more about the optimization project and see the results via the link below.

Source: A 40m High Performance Antenna for Field Day | Our HAM Station

Our Field Day Wire Antenna information package has been updated to reflect the results of the optimization work. We have also added additional information to make the setup and tuning of our wire antenna including the 40m V-Beam easier. You can see the information package here.

Why Does The Antenna Formula 234/f Work?

antenna formula

The formula 234/f is a handy way to estimate the size of a ¼ wave antenna element based on the desired frequency for the antenna. Here is how to derive that number using only other constants and conversion ratios.

How big is a ¼ wave for a given frequency? We can use the band name as a hint (14 MHz is called 20m) but we need a more exact size.

The speed of light in a vacuum (c) is 3 x 108meters per second. The wavelength (λ) for a given frequency (usually referred by ν, but we’ll call f) is defined to be c/λ. Wavelength is the speed of light divided by the frequency. So, the wavelength in meters is:

We only want to know the size of a single cycle for this frequency so we can divide both the numerator and denominator by a million. That makes the numbers much smaller! Wavelength in meters is now:

That is, wavelengths in meters uses this simple formula:

But, we want this in feet (because we’re Americans) so we need to convert meters to feet. One meter is about 3.28 feet. So, convert wavelengths to feet:

which is

But we don’t want a whole wavelength; we want just a quarter of that for our dipole arm. Divide the whole thing by four.

which gives us

Why is this 246 and not 234? This is because we are using the speed of light as the speed of the current in the wire. But, nothing goes as fast as light but light! We need to put in the velocity factor for the wire (which is relative to the speed of light) to know how big a quarter wave is in the wire.

Choose 0.95 as the velocity factor as a guess for most antenna wire. That is, the charge propagates down the wire at about 95% of the speed of light.

which gives us the formula

The formula 234/f isn’t “magic”; it is just a distillation of the simple formula speed-of-light/frequency with all the unit conversions and velocity factor assumptions baked-in.

** Dipole animation from wikipedia.org

Posted by Scott, NE1RD