Category Archives: VHF-UHF

Posts related to UHF and VHF equipment and operations

Propagation Prediction Websites

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Is 20 meters open to the location of the latest DXPedition on the bands?   When is 6 meters open for Sporadic E?  Looking for a weak signal 2-meter contact with a specific grid square?  There are websites you can visit that give you a prediction of whether the band you are on is open to a given destination.

HF Propagation

N0NBH Propagation Widget

N0NBH Propagation Widget

The simplest HF propagation prediction is the widget that is seen on many Amateur Radio Websites – QRZ.com, DXSummit.fi, and more.   This gives you a rough idea of what bands are open day and night. Data is based on the Sunspot Number, A and K indices and other indices.  But this doesn’t take into account many factors like your location, the DX location, the characteristics of your station and the DX station.  Just because 15m says Poor doesn’t mean you won’t hear anything on the band.

VOACAP – HF Propagation Prediction

VOACAP Point to Point Prediction

VOACAP Point to Point Prediction

VOACAP, is the Voice of America Coverage Analysis Program, and provides detailed information about the HF propagation.  You can choose transmitter and receiver locations from many cities around the world.  It also provides choices of Antennas, Power, Mode, and more for each end of the contact. You can look at several different views of propagation.  If you spend some time delving into the details of propagation visit this site.

VOACAP Prediction from DXSummit.fi

VOACAP Prediction from DXSummit.fi

For a faster view of whether you will be able to contact a specific DX Station that is currently on the air,  the DXSummit.fi spotting website has incorporated propagation predictions on their website.  If you find a DX station spotted there that you contact, just right click on the DX callsign and select VOACAP from the drop-down.   You just need to choose whether you are a Basic (100 watts and a Wire) or a Super station (Amplifier and Directional Antenna).  You can also look at views of Short Path or Long Path.  It will give you a good view of when you need to be on which band to contact the DX station.

6 Meters – The Magic Band

DXMaps - 6 meter openings

DXMaps – 6 meter openings

The best website that I have found for 6 meters is DXMaps.com .  It provides a map view of the world or you can select a continent. Based on spotting network data, it shows 6 meter contacts and color codes them by Sporadic-E, Multihop ES, Meteor Scatter, etc…  even Aurora.  You can also get a view of 10 meters, 2 meters or 70 cm.  If you sign up for a free account, you can subscribe to real time notifications when there is an opening near you.

2 Meter Propagation

VHF Propagation Map

VHF Propagation Map

Looking for a tropo opening for a weak signal 2-meter contact?   Visit the website http://aprs.mountainlake.k12.mn.us/ to see a VHF Propagation map.  This shows tropo openings as color-coded clouds – with brighter colors for the longer openings.    This is based on APRS data.

These are the websites that I like to visit to understand the propagation forecast for the day.  If your favorite site is not on the list, add a comment so that the rest of our readers and we can check it out.

Anita, AB1QB

A Portable Satellite Station Part 5 – Plans for Our 3.0 Station

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Satellite Grids Worked

Satellite Grids Worked

We’ve made about 250 contacts with our Portable Satellite Station 2.0 and we have worked 106 grids which should be enough to earn a Satellite VUCC. The picture above shows the grids that we’ve worked via Satellites. We’ve learned a lot about satellite operation and had a great deal of fun in the process!

Portable Satellite Station 2.0 Goals

Portable Satellite Station 2.0 Goals

We’ve met all of our original goals for our 2.0 Station and we’ve used it portable at License Classes, Field Day, and other Amateur Radio Demonstrations. We’ve also shared presentations about our 2.0 Station with Amateur Radio Groups here in the New England area. The question that we get most often about the 2.0 Station is “What are your plans for the Portable Satellite Station 3.0”?

Portable Satellite Station 3.0 Goals

Portable Satellite Station 3.0 Goals

Well, here is the plan. We are working with a local group to secure and host an ISS Crew contact. The ARISS folks have published ground station requirements for these contacts. Here are the primary station requirements:

  • Transceiver with 50–100 W output, 1 kHz tuning steps, and 21 memories capable of storing split frequencies
  • Low-loss coax (such as 9913 or LMR-400)
  • Mast-mounted receive pre-amplifier
  • 14-element yagi antenna with switched circular polarity
  • Antenna rotators for azimuth (0–360°) and elevation (0–180°), with an interface for computer control
  • Computer running tracking software for antenna control (including flip mode operation)

Fortunately, our 2.0 Station meets or exceeds almost all of the primary station requirements with the exception of the antennas. The required antenna upgrades will shape the plans for our Portable Satellite Station 3.0.

M2 Antenna Systems 2MCP14

M2 Antenna Systems 2MCP14

ISS Crew Contacts are conducted using 2m Simplex radios on the ISS. We choose the 14-element circularly polarized 2MCP14 yagi from M2 Antenna Systems to meet the ARISS requirements for 2m. Here are the specifications for this antenna:

2MCP14 Antenna Specifications

2MCP14 Antenna Specifications

The 2MCP14 antenna offers a good balance between gain (12.34 dBi) and boom length (10′-6″) and is near the size limit that is practical for use in our Portable Station. This antenna provides an additional 3.14 dBi of gain compared to the M2 Antenna Systems 2MCP8A yagi which we are currently using in the 2.0 Station.

M2 Antenna Systems 436CP30

M2 Antenna Systems 436CP30

While not required for an ARISS Crew Contact, we are also going to upgrade the 70cm yagi to a 30-element circularly polarized M2 Antenna Systems 436CP30 yagi. Here are the specifications for this antenna:

436CP30 Antenna Specifications

436CP30 Antenna Specifications

This antenna is a good match for the upgraded 2m yagi. The 436CP30 has a boom length of 9′-9″ and a gain of 15.50 dBi. This antenna will provide an additional 2.2 dBi of gain compared to the M2 Antenna Systems 436CP16 yagi which we are currently using in the 2.0 Station.

Satellite Antennas Setup Portable

Satellite Antennas Setup Portable

The new antennas will require some modifications to our portable antenna system arrangement. They will need to be mounted on a cross-boom near their centers. As a result, a non-conductive fiberglass cross boom will be required to avoid problems with pattern distortion.

FGCB60 Non-Conductive Cross Boom

FGCB60 Non-Conductive Cross Boom

We will be using an M2 Antenna Systems FGCB60 Cross Boom which has removable, non-conductive end sections made from fiberglass material. The removable ends will make it easier to transport the antenna system. We will also need to make a new mast which is 24″ longer than our current one in the 2.0 Station to create the needed ground clearance for the longer antennas.

Alfa Spid Az-El Rotator

Alfa Spid Az-El Rotator

We are also planning to use a larger Alfa Spid Az-El Rotator. This unit will handle the extra weight of the longer yagi antennas and cross boom assembly and is more precise than the Yaesu unit used on the 2.0 station.

PS-2M and PS-70CM Polarity Switches

PS-2M and PS-70CM Polarity Switches

The last piece of the 3.0 Station Antenna upgrade is to add switchable left-hand and right-hand circular polarity. This will be accomplished via M2 Antenna Systems PS-2M and PS-70CM switchable polarity feed point upgrades for the 3.0 yagis.

DXEngineering EC-4 Control Box

DXEngineering EC-4 Control Box

We have a DXEngineering EC-4 Control Box from a previous project and we can use it to control the relays in the Polarity Switches which will be part of the 3.0 Station antennas. The box will allow us to select any combination of left and right-hand circular polarization on the 3.0 Station uplink and downlink antennas.

We should have all of the parts here for the 3.0 upgrade by the end of the year. We’ll post more as the project proceeds. Other articles in the Portable Satellite Station series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

Fred, AB1OC

Meteor Scatter Rocks! – Work’in the Orionids

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AB1OC 6m USA Grids

AB1OC 6m USA Grids

I’ve been pretty active on the 6m Band the past few years. As you can see from the image above, we’ve worked most of the grid squares in the eastern third of the United States on 6m. I use a mix of modes on 6m, including SSB Phone, CW, JT65, FT8, and MSK144. The addition of the MSK144 mode for Meteor Scatter contacts has been a lot of fun and has added some new grid squares to my total.

Orionid Meteor Shower Forecast

Orionid Meteor Shower Forecast

One of the fall Meteor Showers, the Orionids, occurred not too long ago, and I decided to focus on MSK144 during the Orionids to see how many grid squares I could work. The shower was most active over 3 days (Friday, Saturday, and Sunday).

MSK144 QSO with WA3LBI Using WSJT-X

MSK144 QSO with WA3LBI Using WSJT-X

The latest WSJT-X software supports a relatively new digital mode for Meteor Scatter contacts – MSK144. A Meteor Scatter contact made using MSK144 is shown above.

Meteor Scatter Pings Detected via MSK144

Meteor Scatter Pings Detected via MSK144

Meteors create short propagation enhancements when they burn up in the atmosphere. These short propagation bursts enable very brief (approximately 1-5 second) propagation on the 6m Band.

The video above shows an example of an MSK144 Meteor Scatter QSO using WSJT-X.

6m MSK144 QSOs During Orionids

6m MSK144 QSOs During Orionids

So I bet you may wonder how many 6m QSOs and grid squares I could work during the Orionids? I made 23 Meteor Scatter QSOs using MSK144 during the 2017 Orionids. The image above shows the 16 grids I worked using MSK144 during the three days. A few of these grids were new for me on 6m.

I used our Flex-6700 SDR, our SteppIR Yagis, and about 200w of power to make these contacts. It was a lot of fun making contacts using MSK144 Meteor Scatter on 6m. I am looking forward to future Meteor Shower activity!

Fred, AB1OC

Students Analyze HAB-2’s Flight Data – Nashua Area Radio Society

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The HAB team members in NARS have created a five-session curriculum to teach physics, atmospheric science, and radio technology that we use as part of our HABlaunches. The last session is the most fun of all – analyzing the telemetry data from our HAB’s flight to see what the students can learn from it.

Source: Students Analyze HAB-2’s Flight Data – Nashua Area Radio Society

We got together with the students who did our HAB-2 launch this week to analyze the data from the flight and to preview some of the videos that HAB-2 captured during its flight. You can read more about what we learned from the flight data on the Nashua Area Radio Society website via the link above

Fred, AB1OC

HAB-2 Sets Altitude Record! – Nashua Area Radio Society

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We flew our High-Altitude Balloon for the second time this past weekend. Our second High-Altitude Balloon Flight (HAB-2) was part of a STEM learning project that we did with STEM club students at Bishop-Guertin High School in Nashua, NH. The students did all of the flight prep and launched HAB-2 at approximately 11 am ET from a school in Winchester, NH. Parents, teachers and local students joined us for the launch as did several members of our HAB team.

Source: HAB-2 Sets Altitude Record! – Nashua Area Radio Society

Our students prepared, launched, and tracked HAB-2 this past weekend. Their HAB made it to almost 118,000 ft! You can read more about the launch and the flight on the Nashua Area Radio Society’s website via the link above.

Fred, AB1OC

Raspberry Pi Satellite Rotator Interface

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MacDoppler and GHTracker

MacDoppler and GHTracker

We’ve been using our Portable Satellite Station 2.0 for some time now, and it works great. One area that can be improved is the interface between the MacDoppler Satellite Tracking program we use and the GHTracker application, which controls the Green Heron Engineering RT-21 Az/El Rotator Controller in our setup. Our initial approach was to run the GHTracker app under Windows/VMWare on the same MacBook Air laptop that runs MacDoppler. While this approach works ok, it was more complex and less reliable than we had hoped.

Fortunately, MacDoppler and GHTracker use a UDP-based interface that will run over an IP network.

GHTracker Running On A Raspberry Pi 3

A Raspberry Pi Satellite Rotator Interface – GHTracker Running On A Raspberry Pi 3

Anita, AB1QB, got great results using a Raspberry Pi 2 with a Touch Screen for her DX Alarm Clock Project, so I decided to do something similar with GHTracker. The new Raspberry Pi 3 Model B boards feature a built-in WiFi networking interface and four USB ports, making the RPi 3 a perfect platform for this project. An email exchange with Jeff at Green Heron Engineering confirmed that GHTracker could run under Linux on the Raspberry Pi (RPi).

We wanted a compact package that did not require anything but a power supply to run the final project. There are many great parts available for building a Raspberry Pi system. Here’s what we used:

The total cost for all of the parts was $120.

The assembly of the case and the hardware was straightforward. The folks at Adafruit provide a pre-built Jesse Linux image for the RPi, including the necessary driver for the Touch Screen Display.

After some configuration work and creating a few shell scripts to make it easy to boot the RPi to an HDMI display or to the Touch Display, we were ready to install the GH Tracker App. We also enabled the VNC Server on the RPi to use a VNC Client application on our MacBook Air instead of directly connecting a display, keyboard, and mouse to the RPi. Finally, we installed Samba on our RPi to allow files to be moved between our other computers and the RPi.

GHTracker Running on the Raspberry Pi

GHTracker Running on the Raspberry Pi

Jeff at Green Heron Engineering provided a copy of GHTracker V1.24 and the necessary serial interface library to enable its use on the RPi. Jeff is planning to make a tar file available with GH Tracker and the library in the near future. We did some configuration work on LXDE (the GUI interface for Linux that runs on the RPi), and it automatically runs GH Tracker whenever the RPi is booted up. We also optimized the GUI for the sole purpose of running GH Tracker on the Touch Screen Display. Finally, we configured the Ethernet and WiFi interfaces on the RPi to work with our home network and LTE Hotspot modem.

RPi GHTracker Test Setup

RPi GHTracker Test Setup

With all the software work done, it was time to test the combination with our Satellite Rotator System. The setup worked on the first try using a WiFi network connection between the MacBook Air Laptop running MacDoppler and the RPi. The USB-based serial ports, which control the Azimuth and Elevation direction of the rotators, worked as soon as they were plugged into the RPi. Also, the touchscreen interface works well with the GH Tracker App making the combination easy to use.

MacDoppler and GHTracker via VNC

MacDoppler and GHTracker via VNC

The VNC Client/Server combination allows us to work with the software on the RPi right from our MacBook Air laptop. It also makes for a nice display for monitoring the GHTracker App’s operation from the Mac.

You can find information about how to build your own Raspberry Pi Satellite Rotator Interface here.

Other articles in the Portable Satellite Station series include:

You may also be interested in the satellite station at our home QTH. You can read more about that here.

Thanks to the help from Jeff at Green Heron Engineering, this project was very easy to do and worked out well. The Raspberry Pi 3 platform is powerful and relatively easy to work with. It makes a great start for many Ham Radio projects. Also, there is a wealth of online documentation, how-to information, and open-source software for the RPi. I hope that some of our readers will give the RPi a try!

Fred, AB1OC

Orionid Meteor Shower: Friday Night Brings Excellent Conditions In Eastern US

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Orionid Meteor Shower Forecast

Orionid Meteor Shower Forecast

One of the best meteor showers of the fall, the Orionid Meteor Shower, will peak on Friday night with over a dozen meteors streaking across the night sky every hour.

Source: Orionid meteor shower: Friday night to bring excellent viewing conditions in the Eastern US.

This weekend will be a good time to work Meteor Scatter contacts on 6m! The Orionid’s peak tonight (Friday) and tomorrow (Saturday) night, October 20th and 21st. We’ll be operating using WSJT-X MSK144 mode on 6m. We plan to use our Remote Operating setup to take advantage of our SDR’s receiver capabilities and the connected 500w amplifier.

Fred, AB1OC

Icom IC-9700 VHF/UHF/1.2GHz Prototype Transceiver

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Source: Icom IC-9700 VHF/UHF/1.2GHz Prototype Transceiver

Another new radio from Icom is based on their SDR platform. This looks like a great radio for Satellite and EME use. We will put in a pre-order for this radio and plan to include it in our Portable Satellite Station. I’ll post more here as details become available.

Fred, AB1OC

Portable Satellite Station Design and Operation

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Building and Operating a Portable Satellite Station Presentation

Portable Satellite Station Design and Operation Presentation

Anita and I attended the New England Regional Hamvention this past weekend. We gave a presentation on Portable Satellite Station Design & Operation there. You can view a copy of our presentation here.

Satellite Station Portable - Radio and Supporting Equipment

Portable Satellite Station 2.0 at a Recent License Training Class

The Videos from our presentation are below –



We did two additional talks about the Nashua Area Radio Club’s activities, including one on our High-Altitude Balloon Project. You can view those presentations here.

Also, we are planning to have our 2.0 Portable Satellite Station setup at the Nashua Area Radio Club’s upcoming Technician License Class on Sept. 30 – Oct. 1. If you are in the area and would like to see the station in operation, please contact us at activities@n1fd.org to arrange for a visit. You can do that here if you’d like to register for one of our license classes.

Fred, AB1OC

Spark Day at the Nashua Academy for Science and Design – Spring 2017

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Explaining Amateur Radio to ASD Students

Explaining Amateur Radio to ASD Students

John Keslo, W1MBG, Jamey Finchum, KC1ENX, and I (all members of the Nashua Area Radio Club) recently had the chance to again visit the Academy for Science and Design (ASD) in Nashua, New Hampshire, to provide an Introduction to Amateur Radio for the students there. ASD’s goal is to be a world-class school specializing in science, engineering, mathematics, and design for students in grades 6-12.

ASD periodically holds SPARK (Symposium Promoting Advancement of Real-world Knowledge) conferences, which enable ASD students to learn about areas that might help them to develop careers in Science, Technology, Engineering, and/or Math (STEM).

The students at ASD are extremely bright and are highly motivated to develop STEM careers. We had about 65 students elect to attend the two sessions that we presented, and the kids showed a lot of interest in our presentations.

Explaining Our High-Altitude Ballon Project

Explaining Our High-Altitude Ballon Project

We began each session with some classroom time where we explained what Amateur Radio is about and some of our club’s Amateur Radio projects. We discussed and showed components of our High Altitude Balloon Project, our Satellite Ground Station, and our Field Day activities. The interest level among the kids was high, and lots of questions were asked.

GOTA Contact during ASD Spark

GOTA Contact during ASD Spark

We also put together an HF GOTA station in the school’s lobby. This allowed the kids to get on the air and experience Amateur Radio firsthand. After the kids got over the usual “mic fright,” they had a lot of fun.

We look forward to our next opportunity to participate in ASD’s SPARK Day in the fall. This is one of the most enjoyable events of the year for me.

Fred, AB1OC