A 40m High Performance Antenna for Field Day

40m V-Beam Wire Antenna at Field Day

40m V-Beam Wire Antenna at Field Day

The Nashua Area Radio Society has been using a 3-element 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

40m V-Beam – EZNEC Antenna View

Our 40m V-Beam antenna was initially designed in 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 for my project.

AutoEZ Antenna Modeling and Optimization Software - Wires Tab

AutoEZ Antenna Modeling and Optimization Software – Wires Tab

AutoEZ is a collection of Visual Basic code and Microsoft Excel macros that act as a front-end to EZNEC 5.0 and later. AutoEZ provides a number of very useful enhancements to EZNEC including:

  • Ability to use formulas and variables to construct and modify EZNEC wire models
  • A Test Case generator and execution environment to vary model parameters and graph the results calculations run by EZNEC
  • An automatic optimizer that can adjust the parameters of an antenna model in EZNEC to optimally meet a defined set of performance goals
  • Harnesses the full power of Microsoft Excel formulas for trigonometry, logical, and other mathematical capabilities for use in EZNEC modeling
AutoEZ Antenna Model Variables

AutoEZ Antenna Model Variables

The first step in the project was to rebuild the EZNEC model that I already had for our 40m V-Beam antenna in AutoEZ. I began by defining several AutoEZ Variables and Excel Formulas in the AutoEZ Variables Tab that enabled me to easily modify the design of the antenna and to optimize it. Some of the basic variables included the target design frequency for the antenna, the height and separation of the antenna elements, the distance to the element anchor points, and the length of the element wires.

AutoEZ Antenna Model Variables (Formulae View)

AutoEZ Antenna Model Variables (Formula View)

The image above shows the model variables in “Formula View”. You can see some of the math and trig functions that were used to compute values for some of the variables. AutoEZ can only optimize variables that do not contain formulas so I was careful to ensure that the base separation between the elements and the length of the element wires were constants as these are the parameters that I wanted to optimize later.

AutoEZ Antenna Modeling and Optimization Software - Wires Tab

AutoEZ Antenna Modeling and Optimization Software – Wires Tab

Excel Trig formulas and the Variables were used on the Wires Tab to determine the coordinates of the wires in the antennas. There are a total of 7 wires in the model. Six are the two ends of the three inverted-V elements. The Seventh wire is a short 4″ section in the middle of the Driven Element to allow a current source to be inserted to drive the antenna there. I was careful to create an accurate model of the wire gauge, insulation, and loss that we are using for our V-beam

Model Variables to be Optimized

Model Variables to be Optimized

With the model built, it was back to the Variables Tab to select the parameters to be optimized. Optimization is best done as a multi-pass process and I did this in two steps. The first set of runs included optimization of both the element spacings and their lengths. This led me to conclude that the mast spacing of 27 ft (Driven to Director) and 28 ft (Driven to Reflector) were the best choices. I then set these as fixed values in the variables tab and ran the optimizer a second time with some starting element lengths to optimize the element lengths by themselves.

Optimizer Objectives

Optimizer Objectives

One must create a set of frequencies and objectives for the optimizer before running it. This is done in the AutoEZ Optimize Tab. The antenna is being used for SSB on 40m so I choose a range of frequencies that covered the SSB sub-band on 40m. Note that I weighted the center frequency heavier than the edges by including it more times in the optimizer’s list. The use of the Optimization Objectives and their associated weights and values are well covered in the AutoEZ documentation so I won’t cover them in detail here. The parameters above were chosen to create a reasonable balance between SWR values across the 40m SSB sub-band, good Front/Back and Front/Side performance from azimuth values ranging from 60º to 300º, and a reasonable amount of forward gain for a 3 element antenna of this type.

I expected that the final impedance of the antenna would be a typical value for a yagi in the 20 to 30 ohm range. Thus, I set the SWR calculations based upon a 25 ohm target impedance. More on the matching of the resulting design later…

Element Optimization Results

Element Optimization Results

It took several runs of the optimizer with different sets of Optimizer Objectives to get the final results I was looking for. The Optimizer tried 130 combinations of element lengths to arrive at the final lengths shown above. Note the improvements in SWR (1.6 -> 1.04), Forward Gain (+1 dB), Front/Back (+4.2 dB) and Front/Rear (actually Front/Side) performance that the Optimizer was able to achieve over my manual, trial and error optimization.

Post-Optimization Model Variables

Post-Optimization Model Variables

Next, I rounded the optimized element lengths and plugged them into the Variables Tab.

Post Optimization Azimuth Pattern

Post Optimization Azimuth Pattern

The image above shows the optimized Azimuth pattern for the antenna as generated by AutoEZ and EZNEC. A very clean result!

Post-Optimization Elevation Pattern

Post-Optimization Elevation Pattern

And here’s the optimized Elevation pattern near the center of the SSB sub-band. This antenna is a little low for 40m but the resulting maximum gain at a 35º angle should work well for US contacts during Field Day.

Calculated Performance for the Optimized Antenna

Calculated Performance for the Optimized Antenna

The final step in the optimization process was to calculate a full set of performance calculations for the antenna using the Calculate Tab. AutoEZ makes it very easy to generate a set of Test Cases for incremental frequencies in the SSB sub-band on 40m. Note the setting of the Elevation angle of 35º to match the maximum gain angle for the optimized antenna. Also, note the parameter settings for Ground Type and Characteristics. I set these to model the less than ideal soil conditions that we have here in New England.

Performance Plots for the Optimized Antenna

Performance Plots for the Optimized Antenna

AutoEZ provides several nice graphical capabilities via the Patterns, Triple, Smith, Custom and Currents Tabs.  I used some of them to plot the data from the performance calculations. These graphs help to visualize the results of the optimization to verify that the design objectives for the antenna have been met.

1:2 Matching Balun (25 ohm to 50 ohm)

1:2 Matching Balun (25 ohm to 50 ohm)

I am using a 1:2 matching Balun from Balun Designs at the feed point of the antenna to transform the antennas final 25 ohm feed point impedance to 50 ohm to match our coax feed line.

40m V-Beam Antenna

40m V-Beam Antenna

We are looking forward to using the optimized version of our 40m V-Beam at Field Day 2018. It took me a couple of days of time to read all of the AutoEZ documentation and learn to use the excellent tools it provides. I don’t think I will build another EZNEC antenna model without using AutoEZ. Even without the optimization features, AutoEZ makes the construction and modification of an antenna model in EZNEC far easier than it would be using EZNEC alone. I hope that you’ll give AutoEZ a try for your next antenna design project.

Fred, AB1OC

 

DX Alarm Clock Part 2 – Hardware

The DX Alarm Clock

The DX Alarm Clock

I recently wrote a blog article about the DX Alarm Clock software – here is Part 2 of the Series on the how I built the hardware for the DX Alarm Clock.

DX Alarm Clock Hardware Components

The DX Alarm Clock is based on a Raspberry Pi 3 computer and an Adafruit Pi-TFT Touch Screen Display.  The list of components, along with links is below.  Since I built the Raspberry Pi almost a year ago and technology is always advancing, some of the parts are no longer available or have better replacements available.  I’ll provide information on what I used and a recommended replacement.  Approximate prices are included.

 

Rapberry Pi 3

Rapberry Pi 3

 

Motherboard: Raspberry Pi 3 ($35) – includes a 1.2 GHz 64-bit quad-core ARM CPU, Build in WiFi, Ethernet, 4 USB Ports, an HDMI port and audio port (3.5″) and Bluetooth.

Also you will need a power adapter  ($10) and Class 10 Micro SD card ($15) for the Raspberry Pi.  Ours is a SanDisk Ultra 64GB Micro SD Card.

Pi-TFT Touch Screen Display

Pi-TFT Touch Screen Display

Display: Adafruit Pi-TFT 2.8″ Display with Capacitive Touch Screen ($45).  A slightly larger, 3.5″ display is now available.

PiBow Case

PiBow Case for Raspberry Pi and Touch Screen Display

Case: Pimoroni PiBow Case for Raspberry Pi and Pi-TFT Display($20)

Kinivo Speaker

Kinivo Portable Speaker

Portable Speaker:  Any small portable/rechargeable speaker will do.  Mine is a Kinivo, but it is no longer available.  Any small speaker will do as long as it is Bluetooth or has a 3.5″ stereo connector.

 

Raspberry Pi Development Environment

Raspberry Pi Development Environment

Raspberry Pi Development Environment

After constructing the Raspberry Pi, case and TFT Display, the next step was to connect it to a monitor via the HDMI port, a mouse via one of the USB ports and to a Bluetooth keyboard.   Then I loaded the Raspbian Operating System onto the Raspberry Pi via the micro SD card.  I first copied the OS to the Micro SD card using a PC or Mac and then inserted the card into the Raspberry Pi and booted from it.  You can find a good tutorial on how to do this at https://www.raspberrypi.org/learning/software-guide/quickstart/

Once Raspbian is installed, you will have a windows like GUI (Graphical User Interface) environment with a web browser, and a number of additional applications included.

This gave me a development environment that I could use to build and test the DX Alarm Clock software.  I used the Python language to develop the software.  I used the Python IDLE development environment, which is included in the Raspbian OS.

Interested in Raspberry Pi Amateur Radio Projects?  See the article on a Raspberry Pi Satellite Rotator Interface.

LEO Satellite Contacts via Easy Sat and Linear Transponder Satellites

Satellite Antenna Details

Satellite Station 2.0 Antennas

We recently did a Tech Night at our club on Building and Operating a Satellite Ground Station. As part of my portion of our Tech Night presentation, I recorded several LEO satellite contacts and made videos showing the operation of the computer controlling our Satellite Station 2.0 during these contacts. These videos give an idea of what its like to operate through LEO satellites.

The video above is a recording of a several contacts through SO-50 – an FM “Easy Sat”.

The next video several contacts made through FO-29, a linear transponder satellite.

The distortion that you hear in my voice is a result of my own voice coming back delayed through the satellites.

We will have our Satellite Station 2.0 setup at Field Day this year. If you are local to Nashua, NH; you are welcome to visit us during Field Day and see our Satellite Station in operation.

You can read more about the station used to make these contacts here on our Blog.

Fred, AB1OC

Quicker-Turnaround Digital Modes in Experimental Stage for WSJT-X Suite

WSJT Screen

WSJT Screen

WSJT-X developer Joe Taylor, K1JT, weighed in to express his appreciation to all who shared their ideas and experiences using JT9 and JT65 modes during recent multi-hop E-skip openings on 6 meters.

“We are very much aware that a mode with most of the excellent characteristics of JT65, but with faster turnaround time, would be a big winner in such situations,” Taylor commented on behalf of the WSJT-X development team. “We are experimenting with several such possibilities. Tentative goals include 15-second T/R sequences, sensitivity around S/N = –20 dB, occupied bandwidth less than that of JT65, and capability to decode as many as 10 or 20 signals in a 2-kHz bandwidth.”…

Source: Quicker-Turnaround Digital Modes in Experimental Stage for WSJT-X Suite

This is something to follow if you are interested in the JT modes for HF and VHF communications. Our experience is that a new JT variant that would trade S/N margin for a faster QSO segment speed would be just the ticket on many of the HF bands as well as 6m.

  • Fred, AB1OC

Nashua Area Radio Society’s 2017 Field Day Station Test

ARRL Field Day is the Nashua Area Radio Society’s largest and most popular activity each year. You can see more about our recent Field Day activities on our Field Day page and on our Blog.

Dave Merchant K1DLM, our Field Day chairman, is bringing some 21st Century radio and computer technology to our Field Day setup this year. There are several aspects to this new component of our Field Day plans including –

  • Two Flex-6700 Software Define Radios running over a network  for our new Digital and enhanced GOTA Stations
  • An on-site WiFi Network to enable using the N1MM+ Logger in network mode for sharing of log information, station activity, real-time scores, and messages
  • A central Score Board and Field Day Information Computer in our public information tent
2017 Field Day Site - Upper Field Layout

2017 Field Day Site – Upper Field Layout

We will again be holding our 2017 Field Day operation at the Hollis-Brookline High School in Hollis, NH. We are planning on using the upper baseball field area as our main operating location. We have decided to add a third tower this year and locate it on a soccer practice field which is situated several hundred feet away from our main operating area. All of our antennas and equipment will lie within the required 1000′ circle but the third tower would situate those operating at that location away from the rest of our group. Dave’s solution to this problem was to set up a network and operate two Software Defined Radios (SDRs) at the lower site remotely from our location on the upper field.

Dave has enlisted Piece Fortin, K1FOP to be our IT Chairman for Field Day this year. Pierce has been instrumental, along with Dave, in the planning and testing of all of this new technology. Pierce and Dave have a great deal of networking and IT experience and knowledge and we could not have put together what is described here without them.

Dave K1DLM, Piece, Hamilton K1HMS, Mike Ryan K1WVO, Anita AB1QB, and I have gotten together multiple times to set up and test all of this new technology. I wanted to share some more about the equipment and the associated testing (which has been staged in the kitchen at our QTH – thank you, Anita!).

We began the testing process by setting up our 20m CW station.

20m CW Station Test

20m CW Station Test

This station uses an Elecraft K3S Transceiver, a K1EL WinKeyer and the N1MM+ Logger running on a Windows 10 Laptop PC. We used this station to get our basic N1MM+ setup including our Field Day CW keying macros right.

40m SSB Station Test

40m SSB Station Test

Next came our 40m SSB station. This setup uses an Icom IC-7300 Transceiver and allowed us to set up and test N1MM+ on the fly audio macro recording and playback. All three of our SSB stations will have on the fly recording and playback capability which will allow each of our SSB operators to record and use a custom set of audio macros.

Digital Station Test

Digital Station Test

Next came our Digital Station. This station uses one of the two remote Flex-6700 SDRs.

Remote Flex-6700 SDRs and Antenna Switch

Remote Flex-6700 SDRs and Antenna Switch

Dave, K1DLM put together a really nice package for the two Flex-6700 SDRs and associated equipment which will be located on the lower field. He used a rack system to mount the two SDRs, power supplies, a three-band Tri-plexor, a set of bandpass filters for 80m, 40m, 20m, 15m, and 10m and a 403A 8×2 networked antenna switch. This setup allows either of the two SDRs to share the tri-band yagi or the 40m and 80m Inverted-V antennas on the tower on the lower field and operate on any of the 5 available HF bands. Antenna and filter switching automatically track the frequencies of the two SDRs making the setup simple to use.

Digital Station Second Display - SmartSDR & More N1MM+

Digital Station Second Display – SmartSDR & More N1MM+

The Digital Station’s remote SDR will be operated using a SmartSDR client running on the Digital Station laptop PC. This station will have a second monitor to better accommodate all of the windows associated with it.

Digital Station Main Display - N1MM+

Digital Station Main Display – N1MM+

The main display associated with the Digital Station will run decoders for all PSK and RTTY modes. The ability to decode multiple PSK signals simultaneously and multiple RTTY decodes are available. The Digital station also acts as the N1MM+ master station in our Field Day setup for all of the other stations which use N1MM+.

Satellite Station Test

Satellite Station Test

Our Satellite Station 2.0 was also added to the test setup. It uses a MacBook Air laptop running MacDoppler to control the antenna rotators and the Icom IC-9100 Transceiver which are part of our Satellite Station. A Windows 10 Surface Pro computer is included which runs N1MM+ and provides logging and other network functionality for our Satellite Station.

GOTA Station Test

GOTA Station Test

We also tested our GOTA station which uses the second Flex-6700 SDR and a FlexRadio Maestro to provide a more conventional “buttons and knobs” interface for our GOTA operators to use. This station will also have a laptop PC running N1MM+ for logging.

Scoreboard Computer

Scoreboard Computer

We also build and tested a Scoreboard PC. This computer will be located in the Public Information tent at Field Day and will be connected to a large display. It will show our real-time score, QSOs being logged as they are made and other useful information about our Field Day operations. This computer will also continuously play videos from our Video Collection and will provide access to IP video cameras which monitor the tower and equipment on the lower field.

Pierce, K1FOP and Hamilton, K1HMS Testing CW Stations

Pierce, K1FOP and Hamilton, K1HMS Testing CW Stations

Our networked N1MM+ testbed contained at least one station of each type (CW, SSB, Digital, Satellite, and GOTA) that will be part of our Field Day setup this year. The Station Masters for the additional CW and SSB stations came by to test their setups using the test bed.

Field Day Networking System

Field Day Networking System

The networking system which Dave and Pierce built is central to all of the technology described here. All of the gear is mounted in a single rack which will be located on the upper field during Field Day. The setup includes a Firewall/DHCP server, a commercial grade outdoor WiFi access point, a 4G LTE modem for Internet access, an Ethernet Switch, and a UPS power supply.

MoCA Data Link Cable

MoCA Data Link Cable

The upper and lower fields at our Field Day site are separated by several hundred feet. A thick line of trees between the two locations raised concerns about connecting the upper and lower sites using WiFi. Pierce came up with a great solution to this problem – we will be using MoCA Data Modems and RG6 Quad Shield 75 ohm Coax Cable to provide a 10 Mbps data link between the two sites. We tested the MoCA link using a much longer run of coax cable then we will need to use at Field Day and confirmed full 10 Mbps throughput.

N1MM+ Talk Window

N1MM+ Talk Window

Our networked N1MM+ setup will allow any station in our setup to send messages to everyone who is operating at Field Day. We can use this capability for important communications like “lunch is ready!” or “I need help from Pierce (our IT chairman) on the 40m SSB station”, or “The 6m band is wide open!”.

Our GOTA and Digital stations will be located together in the same tent and will provide our Field Day 2017 visitors to see and use 21st-century Amateur Radio technology to make contacts. We are expecting young people who participated in our High-Altitude Balloon project and from other local schools where we have done Amateur Radio activities to attend. In additional to being a learning opportunity for all of us in the Nashua Area Radio Society, we hope that the state of the art technology that we are using will generate interest among our visitors. If you are local to the Nashua, NH USA area, come pay us a visit during 2017 Field Day. We’d enjoy providing a tour for you and your family along with a chance to Get On The Air. Hope to see you at Field Day!

Fred, AB1OC

Why Ham Radio?

Scorpion SA-680 Screwdriver Antenna

Fred’s Truck with Antenna

Every so often, I drive Fred’s truck into work and people ask me what that big antenna on the back of the truck is for. I explain to them that it is for Ham Radio.  But the reply is usually, why ham radio – isn’t that outdated technology?  We have cell phones and IM, etc…what do we need Ham Radio for?  So I thought I would put down my thoughts as a relatively new Ham about why I enjoy spending so much of my time with Ham Radio.

amateur_radio_could_save_lives_in_times__2205260000_9445423_ver1-0_640_480

Amateur Radio for Public Service

Public Service

The number one reason we still need Ham Radio along with all the other technology we now have is for public service.  When there is a disaster and cell phones, television, etc are all not working, Ham Radio operators provide the critical communication.

Ham Radio operators help locally to keep hospitals and first responders in contact with each other to help those affected by the disaster.

Hams also use our ability to communicate around the world on HF bands to help family members around the world to get in touch with loved ones affected by a disaster.

Ham Radio operators have been on the scene helping in every disaster from the earthquakes in Nepal to the recent flooding in California.

hamsats

Amateur Radio Cube Satellites

Technology and the Maker Movement

I only became a Ham 5 years ago but many of my fellow Ham Radio operators got their license when they were in their early teens and used what they learned to launch their careers. Many have had very successful careers in STEM fields, all launched by their interest in Ham Radio at a young age.  As technology advances, so does the technology used in our hobby.   We even have a nobel laureate, Joe Taylor K1JT who is a ham. Joe has developed weak signal digital communication modes that let us communicate by bouncing signals off the moon!

As technology has advanced, so has the use of it in Ham Radio.   Most Ham Radio operators have one or more computers in their shack.  Many also have a software designed radio (SDR), where much of the radio functionality is implemented using Software, we use sound cards to run digital modes, which are a lot like texting over the radio, and we use the internet extensively as part of operating.  We can also make contacts through satellites orbiting the earth and even the International Space Station.

Most hams love do-it-yourself technical projects, including building a station, home brewing an antenna, building a radio or other station component.  In my day job, I am a program manager for software development projects, but its been a while since I have built anything. As a Ham I taught myself how to code in Python and about the Raspberry Pi and I built the DX Alarm Clock.

vk6lc

QSL Card from VK6LC in Western Australia

International Camaraderie

One of the coolest things about being an amateur radio operator is that you can communicate with other hams all over the world. Ham Radio is an international community where we all have something in common to talk about – our stations and why we enjoy ham radio.    The QSL card above is from a memorable QSO with Mal, VK6LC, from Western Australia, who was the last contact that I needed for a Worked All Zones award.  I must have talked to him for 1/2 hour about his town in Australia and his pet kangaroos!

world-map

Amateur Radio Map of the World

Geography Lesson

I have learned much about geography from being on the air and trying to contact as many countries as I can.  There are 339 DX Entities, which are countries or other geographical entities and I have learned where each one is in order to understand where propagation will allow me make a contact.  I have learned a great deal about world geography. Through exchanging QSL cards often get to see photos from so many areas of the world.

dxcc-challenge-award

DXCC Challenge Award Plaque

Achievement – DXing and Contesting

DXing and Contesting provide a sense of achievement and exciting opportunity for competition. Many Hams work toward operating awards. You can get an operating award for contacting all 50 states, contacting 100 or more countries, contacting Islands, cities in Japan, countries in Asia, or anything else you can imagine.  Each of these operating awards provides a sense of accomplishment and helps to build skills.  Contesting builds skills through competition among Hams to see who can make the most contacts with the most places in 24 or 48 hours. Contesting also improves our operating skills and teaches us to copy callsigns and additional data accurately.

anita-instructor

Teaching a License Class

Teaching Licensing Classes – Passing it On

Recently I have joined a team of club members who teach license classes to others who want to get licensed or upgrade their existing Amateur Radio licenses.  Teaching provides a way to improve my presentation skills and also helps me to really understand the material that we teach about Amateur Radio.  It is always a thrill at the end of the class to see so many people earn their licenses or upgrades.

There are so many interesting aspects of Ham Radio which is what makes is such a great hobby.  Getting your license can open up a world of possibilities.  Upgrading to a new license class provides more opportunities to communicate over longer distances.  Ham Radio clubs, including our local club, the Nashua Area Radio Club,  provide many resources to help you get your first licenseupgrade to a new license class, and learn about the many aspects of our hobby.

A New Project – Digital Fast Scan Amateur Television

Digital ATV CQ Call

Digital ATV CQ Call

Skip, K1NKR a local friend and VHF/UHF expert and I began talking about the idea of building a Fast Scan Amateur Television (ATV) System some time ago. Our early research and the antenna equipment which we had in place at our stations led us to plan our ATV project around the 70 cm band. The 70 cm band plan in the United States has allocations for Fast Scan ATV transmissions with a bandwidth of up to 6 MHz. Our research led us to Jim Andrews, KH6HTV’s excellent website where we discovered that it was possible to build a Digital ATV station using reasonably priced commercially available DVB-T format Modulators and Demodulators. Jim’s site has a wealth of great Applications Notes on Digital ATV and it’s a great place to start to learn about this technology. A combination of a DVB-T Modulator and Demodulator from Hi-Des was chosen as the heart of our Digital ATV System. We also worked with Jim to secure the needed Wideband Linear Power Amplifiers for the 70 cm band. We began receiving the equipment to build our Digital ATV Stations late last year. We’ve done quite a bit of testing on the air and some custom development work which has resulted in a pair of excellent performing Digital ATV stations. The picture above shows a Digital ATV “CQ” that I sent to initiate one of our early QSOs.

Digital ATV Transceiver

Digital ATV Transceiver

Here’s a picture of Skip receiving my “CQ” at his end. The picture quality produced by the equipment that we’re using and the DVB-T format is phenomenal. The Hi-Des Modulator which we are using has a large number of parameters which can be set to determine the format and bandwidth of the signals we generate. After some experimentation, we have settled on using QPSK modulation and a 6 MHz signal bandwidth. This combination delivers excellent picture quality with more than adequate motion performance. We see very few if any picture artifacts using our current format. We’ve also done some experimentation with QPSK and a 4 MHz signal bandwidth. I plan to share more on signal formats in a future article on our blog.

Digital ATV System User Interface

Digital ATV System User Interface

We are both using HD Digital Camcorders as our primary video signal sources and 1080p monitors to display our received signals. I opted to include an HDMI Video Switch from Gefen in my setup which also allows me to send video and graphics from a variety of different sources including my PC over the air. The monitor in the picture above on the right is a touch screen display which I use to control my ATV Transceiver system.

AB1OC Digital ATV Transceiver

AB1OC Digital ATV Transceiver

Early on, I decided to build a Transceiver like a setup. I wanted to create a unit which was simple to use just like the HF Transceivers that are available today. Some of the key capabilities that I wanted to create include:

  • Real-time selection and switching between multiple HD video sources
  • Transmission of PC sourced Video and Graphics over the air
  • Preview and cueing of the next video transmission while receiving
  • Simultaneous display of both receive and pending transmit video
  • Built-in Transmit/Receive (T/R) switching with termination and protection of the Tx power stage
  • Sequencing of T/R stages including my tower mounted pre-amplifier system
  • Power and SWR monitoring with automatic trip on high SWR
  • An internal low-noise RF preamplifier to provide additional receive signal gain if needed
  • Touchscreen graphical interface for configuration and operating the system
  • Recording of both sides of on-air video QSOs to an attached PC

To achieve these goals, I decided to build a Raspberry Pi 2 based Linux controller of my ATV Transceiver and to package all of the ATV components and video switching/conversion gear needed in a small rack mount enclosure. Many of the components in the system communicate with each other over an Ethernet LAN and the transceiver is networked to computers and other devices via an external Ethernet connection. More on the details of the Transceiver design to come in a future article.

Skip and I recently produced a short video to demonstrate how Fast Scan Digital ATV works and to show the quality that these systems are capable of producing. Our project is still a work in progress and I expect that we will continue to learn as we perform more tests and continue development of our systems. I plan to post additional articles here to share the details of our designs and learning from our on-air testing as we proceed.

– Fred (AB1OC)

2015 Field Day Station Test

Field Day QTH

Field Day QTH

It’s almost time for the 2015 Field Day Event and we’ve been in high gear getting ready. Anita, AB1QB and I will be operating with the Nashua Area Radio Club, N1FD this year. The club was very active in WRT2014 and we were able to purchase several of the WRTC station and tower kits from that effort. I will be operating the 20m SSB station for Field Day and Anita and I decided to setup our station kit in our backyard last weekend to verify that all of our equipment was ready and in good working order. The first step was to pitch the wall tent from the WRTC kit. The tent and the associated tables/chairs can comfortably hold 3 – 4 people.

Field Data SSB Station Test

Field Data SSB Station Test

I will be using our Elecraft KX3 Transceiver again this year. We’ve added an outboard KXPA100 100w Amplifier to bring the station up to 100w and Elecraft’s very nice PX3 Panadapter. The combination makes a great 100W Field Day Station.

Elecraft KX3 Field Day Station

Elecraft KX3 Field Day Station

The picture above is a closer view of the setup. The KXPA100 Amplifier and the PX3 Panadapter are fully integrated with the KX3 and the combination creates a 100W transceiver with a useful Panadapter. The Panadapter should be helpful for Search and Pounce operation during Field Day. I’ve also added a Behringer HA400 four channel headphone amplifier (the unit on the right on top of the power supply) to the setup. This enables connection of a total of 4 sets of headphones to the station – one for the operator, one for a logger and two more pairs for folks to listen in on the fun. Our club has been doing a great deal of outreach to encourage new HAMs to join the hobby and I built this setup so that some of the new folks can listen in on our operation more easily. I will be using a Heil Pro 7 headset to operate and we will have 3 sets of Heil Pro Set 3 headphones for others to use. The Heil gear is very comfortable, light weight and sounds great over the air.

N1MM+ Logger

N1MM+ Logger

I will be using the excellent N1MM+ Logger for Field Day this year. It was very easy to setup N1MM+ to work with the KX3. I was also able to use it to trigger the KX3’s voice message memories for calling CQ and for calling in Search and Pounce mode. I am doing an N1MM+ clinic at our final Field Day prep meeting tonight to help others in our club to get going on the N1MM+ logger.

Generator Test

Generator Test

One of the many great aspects of Field Day is that it results in a test of one’s emergency equipment and operating skills each year. Our club has a large generator and power distribution system that we all share for Field Day so I used our station test session as a reason to get my smaller generators out for a test run. We have a pair of Honda EU2000 generators which can be used together to generate quite a bit of power. Here’s one of them in use during our station test.

Our club has quite a bit of antenna equipment and we will be putting up two 40 ft towers and tri-band beams with Triplexes and Filters for our 20m, 15m and 10m SSB and CW stations. I’ve built a 40m Delta Loop for our club to use for 40m SSB and we’ll be putting up 40m and 80m inverted-V and dipole antennas to cover those bands. I plan to do another post after Field Day is done on the setup of our antennas and the N1FD operation. I hope to work some of our readers on the air during Field Day this year.

– Fred (AB1OC)

HF Mobile – Planning A U.S. County Hunter’s Tour

2015 Dayton, OH County Tour

2015 Dayton, OH County Tour

Anita (AB1QB) and I have been having a lot of fun with our Mobile HF station since we completed it several months back. We’ve been working quite a bit of DX and we make some contacts whenever we are out doing errands or taking other trips. We are planning to attend the Hamvention in Dayton, OH again this year and Anita suggested that we use the trip to activate some most wanted United States Counties along the way.

CQ US-CA Award

CQ US-CA Award

U.S. County Hunters are Amateur Radio operators seeking to work and confirm all 3,077 U.S. Counties. CQ Magazine has an awards program for U.S. County Hunters. Quite a few Amateur Radio operators work all U.S. Counties – some do this using multiple modes and several have done it multiple times. To find out more about the US-CA Award, see the excellent County Hunter Dot Com site.

The Mobile Amateur Radio Awards Club (MARAC) is a support group for county hunting and mobile activities with members all over the world. This is a great organization to join if you are interested in County Hunting. MARAC provides additional awards center around County Hunting and mobile operating.

You can also view WY7LL’s video on YouTube for a nice introduction to County Hunting, MARAC and the tools that the group provides to help County Hunters.

Anita did the planning for our County Tour to Dayton, OH and back. She began by looking at looking at the County Hunter’s Web most wanted page to determine which counties lie along potential routes between are home and Dayton, OH were most needed by County Hunters. Based upon this information, she created the route shown at the beginning of this post. As you can see, we are taking different routes going to Dayton, OH and back to allow us to activate as many U.S. Counties as we can. We are also taking a few side trips off our route to activate a few of the most needed Counties near our route.

Date

States Counties
SundayMay 10 MA Middlesex, Worcester
CT Windham, Tolland, Hardford, Litchfield, New Haven, Fairfield
NY Putnam
NJ Bergen, Passaic, Morris, Somerset, Hunterdon, Warren
PA Northampton, Lehigh, Berks, Lebanon, Dauphin
MondayMay 11 PA Northumberland, Montour, Union, Snyder
TuesdayMay 12 PA Cumberland, Fulton, Bedford, Blair, Cambria, Indiana, Westmoreland, Fayette, Greene
WV Marshall, Wetzel, Tyler
OH Monroe, Washington
WednesdayMay 13 OH Athens, Meiga, Gallia, Lawrence, Scioto, Pike, Ross, Greene, Montgomery
SundayMay 17 OH Clark, Madison, Union, Delaware, Morrow, Richland, Ashland, Wayne, Medina, Summit, Cuyahoga, Lake, Ashtabula
PA Erie
NY Chautauqua, Erie, Niagara, Orleans, Monroe, Livingston, Ontario, Wayne, Seneca, Cayuga, Onondaiga
MondayMay 18 NY Oswego, Madison, Oneida, Herkimer, Montgomery, Fulton, Schenectady, Albany, Columbia
MA Berkshire, Springfield, Hampshire, Worcester, Middlesex

Planned U.S. County Activation Schedule

The table above shows the 86 U.S. Counties that we plan to activate on our trip along with a rough idea of our schedule.

County Finder App

County Finder App

We found a useful iPhone App (County Finder) that will tell us what County we are in at a given time. The County Finder App uses the GPS in our iPhones to provide our current location in real-time.

Ham Clock Grid Square App

HamClock Grid Square App

We will also be tracking and logging the current grid square that we are operating from. We will be using the HamClock App on our iPhones to determine our grid square of operation in real-time.

Mobile Logging

Mobile Logging

Anita and I will be taking turns operating and logging. We are planning to use a laptop computer running the DXLab Suite and we will connect it directly to the IC-7000 Radio in our truck. This combination plus the County Finder and HamClock Apps above should allow us to accurately log all of our contacts. We will also be uploading contracts that we make to eQSL, LoTW and ClubLog in real-time as we operate.

OpenAPRS App

OpenAPRS App

We will also be running an APRS station so that folks can see where we are located in real-time and follow our progress. We are using the OpenAPRS iPhone App for this purpose. Our APRS callsign with be AB1QB-15 and you can see our position and progress on aprs.fi at any time by clicking here.

N1FD Special Event QSL Card

N1FD – Nashua Area Radio Club QSL

Anita and I are members of the Nashua Area Radio Club and we will be operating using the Club’s call sign, N1FD/M, during the trip. In addition to the electronic QSL’ing methods mentioned above, we will also be able to provide paper QSL’s using the Club’s QSL card shown above. All paper QSLs that we send will note the correct County and Grid Square from which the QSL’ed contact was made. See N1FD on QRZ.com for QSL information.

Band County Hunters Net Frequency (SSB)
20m 14.336 & 14.271 MHz
40m 7.188 MHz
80m 3.901 MHz
17m 18.136 MHz
15m 21.336 MHz
12m 24.936 MHz
10m 28.336 MHz

County Hunters Net Frequencies

We plan to operate on or near the County Hunters Net Frequencies listed above. We will be QRV SSB on all of these bands and we may also do a limited amount of operating on 160m SSB as well.

Scorpion SA-680 Screwdriver Antenna

Our Mobile HF Station

We hope that you will take some time to work us during our trip. If you do and you read our Blog, please let us know. If we do not have other stations calling, we’d like to take a little time to say “hello” and get to know some of our readers better. We will also be attending the County Hunter’s Forum on Friday, May 15th at this year’s Dayton Hamvention. If you are there, please introduce yourself and we’ll have an “eyeball QSO”.

– Fred (AB1OC)

2015 DX’ing – One Of The Best Years Ever So Far

March 2015 DXpeditions

March 2015 Featured DXpeditions

2015 has been quite a year for working new DXCC’s for us so far. This month is the most productive that I have experienced with more than 20 interesting DXpeditions on. We’ve been fortunate to have the chance to work the DXpedition on Navassa Island (#2 on ClubLog’s most wanted list) which took place in February of this year. In addition those show above, there are also quite a few small operations including E51UFF on North Cook Island and VP8DOZ on South Georgia Island (#9 on ClubLog’s most wanted list) being on. Also, Eritrea, E30FB which is operating right now is #20 on ClubLog’s most wanted list. All of this makes for a great opportunity to work all-time new ones as well as to add new DXCC Band-Points.

Anita, AB1QB has worked 13 all-time new DXCC’s and I’ve worked 5 all time new DXCC’s since the beginning of 2015. Anita has broken the 250 DXCC barrier and I’m just 2 away from breaking 300. There have also been quite a few new IOTA’s for us. Anita has added 11 IOTA’s this year and I’ve added 14. We also added more than 85 DXCC Band-Points each towards our DXCC Challenge Award totals. I have set a goal to work at least one new DXCC Challenge Band-Point each day in 2015 in hopes of getting to the 2,000 DXCC Band-Point level before the end of the year (I am currently at 1,785 worked).

Shack Board

Shack Board – Upcoming Operations and Contests

We use a number of different sources to find out about these operations. Our favorite ones are The Weekly DX, the DX-World.net (the source of the graphic above) and DX Publishing’s QRZ DX. These are all excellent sources for finding out about upcoming DXpeditions, small DX operations and IOTA activations. Working DX contests such as CQ WW DX, the ARRL DX Contests and CQ WW WPX are also excellent ways to work new DXCC’s and new Band-Points. We have a whiteboard in our shack where we record upcoming operations that we need as well as contests that we want to participate in. This helps us keep track of what is coming up that we need.

DXLab SpotCollector

DXLab SpotCollector

We also use the SpotCollector component of the DXLab Suite to help us identify new DXCC’s, Band-Points, IOTA’s and WAZ Band-Zones that we need in real-time when they come on. We have also used SpotCollector to alert us when stations that we need for the Yearly CQ DX Marathon are on the air.

Spot Sources Configuration In SpotCollector

Spot Sources Configuration In SpotCollector

We have configured SpotCollector (the spotting component of DXLab) to aggregate spots from a variety of sources. Our logs are kept in DXLab and we program the SpotCollector to filter all of the incoming cluster spots and CW/RTTY Skimmer data to tell us about high-priority stations that we want to work when they are on the air. The key to this approach is careful filtering of incoming cluster and skimmer spots to only display and forward the most important opportunities.

Award Setup in DXKeeper

Award Setup in DXKeeper

The first step in the filtering is to configure DXLab’s DXKeeper component for the types of contacts that we are interested in. This is done in the Award configuration section of DXKeeper.

SpotCollector SQL Filter

SpotCollector SQL Filter

We then use the powerful SQL script capability of SpotCollector to only tell us about stations that we are willing to “head for the shack to work”. SpotCollector is configured to send the appropriate spots as text messages via email to our mobile phones so that we know immediately when something that we need comes on. The filter above selects all-time new DXCCs, new DXCC Band-Points, new IOTA’s and new WAZ Band-Zones which are spotted in the Eastern or Central United States. The filter also picks up new Band-States for the ARRL Worked All States Award.

We hope our readers who are interested in working DX and IOTA’s will be able to find some time to work so of the operations that are on the air right now. This time period is certainly one that has a lot of potential to put “new ones” in the log. If you use the DXLab Suite, you might try some to use some of the more advanced features of SpotCollector to help you to better find stations that you want to work when they are on.

– Fred (AB1OC)