EME Station 2.0 Part 10 – Antennas On The Tower

Completed 2m EME Antenna System

After a year’s worth of planning and 10 months of construction, we have our new 2m EME Antenna System installed on our EME Tower and working! This stage of our project took about a week and included a lot of help from Matt and Andrew at XX Towers.

Final Preparations

Antenna Ground Test

The first step was to arrange the four 2MXP28 Yagis that we built on saw horses near our EME Tower and check each antenna’s vertical and horizontal SWR. Performing SWR measurements with the antennas close to the ground like this does not produce very accurate measurements. Doing this does allow one to spot potential problems if some of the measured SWR fail to show a resonance or are wildly different than the other antennas in the group. All of our antennas checked out as expected.

50 Ft Boom Lift, H-Frame Cross Boom Assembly On The Ground

We also rented a 50-ft Boom Lift and set it up near our EME Tower. A tool like this is almost essential to safely assemble and adjust a large, complex antenna system involving an H-Frame. It also speeds up the assembly and adjustment process considerably.

Elevation Rotator and H-Frame

Elevation Rotator Installation on Mast

Elevation Rotator Installation on Mast

The first step was to install the MT-3000A Elevation Rotator on the mast. We pre-installed the control cable for the elevation rotator before installing it on the tower. This enabled us to get it temporarily hooked up to the Rotator Controller in our shack so that we could adjust the elevation of the H-Frame and Antennas as we installed them.

H-Frame Assembly on Tower

H-Frame Assembly on Tower

Next, Matt and Andrew installed the H-Frame Crossboom and Truss assembly on the Elevation Rotator. The assembled Vertical Risers went on next to complete the H-frame. The time spent pre-assembling these components and marking centers to enable accurate final assembly saved a great deal of time.

Antenna Installation

Upper Antenna Installation

Upper Antenna Installation

With the H-Frame in place, we installed the upper 2MXP28 Yagi Antennas next. The image above shows the rigging of the boom trusses which was done on the Tower.

Lower Antenna Installation and Adjustments

Lower Antenna Installation and Adjustments

Next came the lower 2MXP28 Yagis. We spent considerable time leveling and aligning all of the Antennas and H-Frame components at this stage.

Feedlines, Electronics, and Balancing

T-Braces and Feedlines

T-Braces and Feedlines

The T-Brace assemblies and Antenna Phasing Lines were installed next. Each Antenna requires two LMR-400 Phasing Lines and these coax cables add considerable weight to the backs of the Antennas. The T-Braces support these cables and help to align the Antennas on the H-Frame.

We replaced the Vertical H-Frame Boom Truss Pipe with a heavy section of Mast Pipe to act as a counter-weight and balance the final H-Frame and Antenna assembly. This step is critical to ensuring a long life for the Elevation Rotator’s drive system and chain.

Phasing Lines, Power Dividers, and Feedline Connections on Crossboom

Phasing Lines, Power Dividers, and Feedline Connections on Crossboom

The photo above shows the final installation of the Power Dividers, Antenna Phasing Lines (there are 8 in total), the MAP65 Preamp Housing, and the Feed and Control Cables that run down the Tower. We took the time to carefully make SWR measurements on each Antenna and check all of the connections to the MAP65 Housing at this stage.

Antenna Integration Details

Rotator Loop

Rotator Loop

The Rotator Loop contains the following cables and Coax Feedline connections from the H-Frame/Antenna assembly:

  • Vertical and Horizontal Rx Feedlines
  • Tx Feedline
  • Elevation Rotator Control Cable
  • MAP65 Housing Control Cable

All of these cables are bundled and securely fastened to the H-Frame Cross Boom and to the Tower. Andrew is a master at this sort of rigging!

Control Cable Connections at Tower Base

Control Cable Connections at Tower Base

I took some time to finalize the Control Cable connections at the base of our tower. Time was spent with a voltmeter doing checks to ensure that everything was connected correctly and working. This effort resulted in the discovery and correction of some wiring errors and a faulty relay in the MAP65 housing. Had I not done these steps, we would have surely destroyed the Preamps in the MAP65 Housing when we transmitted for the first time.

Testing Our New Antenna System

Vertical Polarity Tx SWR at Shack

Vertical Polarity Tx SWR at Shack

A series of SWR measurements were taken before sealing the coax cable connections on the tower. SWR measurements were checked and recorded for future reference at the following points in the feedline system:

  • At the ends of the phasing lines associated with each antenna
  • At the output of the two Power Dividers on the tower
  • At the shack entry ground block

Measurements were taken separately for both the Vertical and Horizontal elements of the final Antenna System. The image above shows a typical SWR measurement for our final Antenna System.

I did many final checks and adjustments while the Boom Lift was still here. These steps included:

  • Checking the oil level in the elevation rotator
  • Re-lubing the elevation rotator chain
  • Adjusting the limit switch stops on the Elevation Rotator to allow enough over-travel for future adjustments and maintenance
  • Checking all hardware for tightness
  • Sealing all coax cable connectors with Coax Wrap and Electrical Tape
  • Making some final adjustments to align the four 2MXP28 Antennas with each other and the H-Frame

Next Steps

The next step in our project will be the integration of our new 2m EME Antenna System into our shack. This step will include the final setup, configuration, and testing of the Rotator Controller, Interim SDR Receiver, Transmitter, Amplifier, and the MAP65 and Moon Tracking Software.

You can read more about our EME station project via the links that follow:

If you’d like to learn more about How To Get Started in EME, check out the Nashua Area Radio Society Tech Night on this topic. You can find the EME Tech Night here.

Fred, AB1OC

ISS Voice Repeater is QRV!

International Space Station (ISS)

International Space Station (ISS)

Thanks to some great work by the ARISS Team, a new Voice Repeater system is operating on the International Space Station! Here is the access information:

  • Mode: FM Voice
  • Uplink Frequency: 145.990 MHz, PL 67.0 Hz
  • Downlink Frequency: 437.800 MHz
IORS Hardware

IORS Hardware and Kenwood Radio

The repeater uses the new InterOperable Radio System (IORS), a space-modified JVC Kenwood D710GA transceiver, and an ARISS developed power supply system.

Kenwood D710GA

Kenwood D710GA

Here’s some more information from the ARISS Press Release:

The ARISS team is pleased to announce that the setup and installation of the first element of our next-generation radio system was completed and amateur radio operations with it are now underway. This first element, dubbed the InterOperable Radio System (IORS), was installed in the International Space Station Columbus module. The IORS replaces the Ericsson radio system and packet module that were originally certified for spaceflight on July 26, 2000.

The initial operation of the new radio system is in FM cross-band repeater mode using an uplink frequency of 145.99 MHz with an access tone of 67 Hz and a downlink frequency of 437.800 MHz. System activation was first observed at 01:02 UTC on September 2. Special operations will continue to be announced.

The IORS was launched from Kennedy Space Center on March 6, 2020, on board the SpaceX CRS-20 resupply mission. It consists of a special, space-modified JVC Kenwood D710GA transceiver, an ARISS developed multi-voltage power supply, and interconnecting cables. The design, development, fabrication, testing, and launch of the first IORS was an incredible five-year engineering achievement accomplished by the ARISS hardware volunteer team. It will enable new, exciting capabilities for ham radio operators, students, and the general public. Capabilities include a higher power radio, voice repeater, digital packet radio (APRS) capabilities, and a Kenwood VC-H1 slow-scan television (SSTV) system…

You can view the full ARISS Press Release here.

I was able to work several stations using the new ISS Voice Repeater this morning. It is very sensitive and uses 5 watts of downlink power with a good antenna on the ISS. I was able to make solid contacts using the Ground Station here using only 1.5 watts uplink power when the ISS was at 10 degrees above the horizon. At least one of my contacts was with a station using an HT with a whip antenna!

The voice repeater is sensitive enough and uses a power level that will enable folks with an HT and a whip antenna to make contacts using the ISS when it is close to the horizon. It should also be easy to make contacts using mobile rigs that can support cross-band operation as well. Program your radios!

I’m looking forward to working you through the ISS!

Fred, AB1OC


Getting Started With Amateur Satellites (and Progressing to Linear Birds)

Get Started with Amateur Satellites

Get Started with Amateur Satellites

We get quite a few requests from folks to explain how to get started with Amateur Radio Satellites. Requests for information on how to build a computer-controlled ground station for Linear Satellites are also pretty common. I recently got such a request from our CWA class so I decided to put together a session on this topic.

We covered a number of topics and demonstrations during the session including:

  • How to put together a simple station and work FM EasySats with HTs and a handheld antenna
  • A recorded demonstration of some contacts using FM EasySats
  • How-to build a computer-controlled station and work Linear Transponder Satellites
  • Fixed and Portable Satellite Station Antenna options
  • A recorded demonstration of some contacts using Linear Satellites
  • How-to work digital (APRS digipeater) contacts
  • How-to receive SSTV Transmissions from the ISS

About 30 folks attended this session and there was some good Q&A throughout.

Getting Started With Amateur Satellites

The presentation was recorded and can be viewed above. Here’s a link to the associated Powerpoint Presentation.

There are lots of articles about building and operating Amateur Satellite Stations here on our blog. The following are links to several articles and series on this topic:

I hope that you find this information useful for your Amateur Satellite projects!

Fred, AB1OC

Tech Night – Getting Started In EME Communications

Tech Night – Getting Started in EME (Click to View The Presentation)

We recently did a Tech Night Program as part of the Nashua Area Radio Society’s educational program. I wanted to share the presentation and video from this Tech Night so that our readers might learn a little more about how to get started in EME or Moonbounce Communications.

April 2020 Tech Night Video – Getting Started in EME Communications

You can see the presentation via the video above. Here’s a link to the presentation that goes with the video. You can learn more about the Nashua Area Radio Society’s Tech Night program here.

We are in the process of building a new 2m EME station that will have adaptive polarity. you can read more about that project here.

Fred, AB1OC

RSU 21 Students to Communicate to Outer Space – Portland Press Herald

Ann Stockbridge, Educator at Kennebunk’s Sea Road School

Ann Stockbridge, Educator at Kennebunk’s Sea Road School

Regional School Unit 21 has been selected for an out-of-this-world opportunity. An international association of space agencies and Amateur Radio organizations has chosen RSU 21, represented by Sea Road School, to advance in a process climaxing in a conversation between students and astronauts aboard the International Space Station (ISS).

RSU 21 was one of 10 schools selected nationally to continue through the multi-month acceptance process. The contact event with the ISS could occur between July and December of this year.

The opportunity is provided by ARISS (Amateur Radio on the International Space Station), an association that includes NASA, the Center for the Advancement of Science in Space, the American Radio Relay League, the Radio Amateur Satellite Corporation, and space agencies in Canada, Japan, Europe, and Russia. They collaborate to enable students to communicate with ISS astronauts and help inspire interest in space, communications and STEM coursework.

Source: RSU 21 students to communicate to outer space – Portland Press Herald

As our readers may know, I have joined the ARISS program as a Mentor to help schools prepare for and make successful contacts with Astronauts on the International Space Station. I am working with Regional School Unit 21 Sea Road School teachers and local Ham Radio folks in Maine, USA to help them make contact with the ISS during 2H2020. The link above shares more about the STEM learning program that is being created around this contact.

Fred, AB1OC

December 2019 ISS SSTV Event

Source: December 2019 ISS SSTV Event – Nashua Area Radio Society

Slow-Scan TV from the International Space Station (ISS) was on the air again late in December 2019.  The ISS SSTV event was in memory of cosmonaut Alexei Leonov. We had our satellite station running to track the ISS and capture the SSTV images during the event. It’s pretty easy to receive these images – it can be done with an HT, hand-held antenna, and a laptop…

This article includes a gallery of the images that we received during the December 2019 ISS SSTV event and some how-to information that you can use to receive SSTV images from the ISS with just an HT and a handheld antenna.

Anita, AB1QB and Fred, AB1OC

An Amazing Experience – Council Rock HS South ISS Contact

Council Rock South Students Contact the ISS

Council Rock South Students Contact the ISS

Its been about a year since we helped students at Hudson Memorial School make contact with the ISS. That contact was enabled by ARISS (Amateur Radio on the International Space Station). ARISS is an organization that coordinates and sponsors Amateur Radio Activities aboard the ISS.

After our contact, I decided to become an ARISS Mentor so I could help other schools make contacts with astronauts aboard the ISS. I spent the last year working with Dave Jordan, AA4KN to learn how the ARISS program works and how to help schools make successful ISS contacts. Dave did a great job coaching me as I worked with Council Rock H.S. South in Holland, PA to prepare for their ISS Contact…

Source: An Amazing Experience – Council Rock HS South ISS Contact

I recently had the privilege of helping Council Rock H.S. South in Holland, PA to make contact with astronaut Drew Morgan on the ISS. The link above shares the story of this amazing experience and my journey to become an ARISS Mentor. The article also contains videos and photos that capture and share the experience. I hope that you enjoy it!

Fred, AB1OC
ARISS Mentor

Listen In On The Council Rock ARISS Contact on Thursday!

International Space Station (ISS)

International Space Station (ISS)

Students at Council Rock High School South in Southampton, PA will be talking with Astronaut Drew Morgan, KI5AAA aboard the ISS on Thursday. The ISS will be over our area here in the Northeastern Unit States beginning at about 12:55 pm eastern time on Thursday, December 5th. Council Rock’s ARISS Contact is made possible by the ARISS Program

Source: Listen In On The Council Rock ARISS Contact on Thursday!

You should be able to hear Drew on the ISS voice downlink at 145.800 MHz FM. The ISS pass will be a high one over our area. As a result, we should be able to hear the downlink using a good vertical antenna and perhaps even using an HT.

You can join the Council Rock Facebook Group for updates and watch a live stream of the contact on Thursday between 12:30 – 1:30 pm.

I am serving as the ARRIS Mentor for Council Rock H.S. South’s ISS Contact. I am looking forward to the opportunity to be at their school on Thursday to be part of what I am sure will be a very memorable event.

You can learn more about the ARISS Program and how to secure an ISS contact for your school here.

Fred, AB1OC

AMSAT 50th Aniversary Celebration – W3ZM/1 Activations in CT and RI

Source: AMSAT 50th Aniversary Celebration – W3ZM/1 Activations in CT and RI

We continued to test our Portable Satellite Station 4.0 as part of AMSAT’s 50th Anniversary Celebration WAS Activations. You can read about the activations and our station’s performance via the link above. Overall, we were pleased with how the portable setup performed. The weakest link was the downlink performance of our antenna system. We are working on some ideas to improve this element of our setup – more to come on this project…

Fred, AB1OC

Learn About Ham Radio at HamXposition @ Boxboro

Remote HF GOTA Station at HamXpositon

The Nashua Area Radio Society will be hosting several activities and displays at HamXposition this year. Our planned activities include:

  • NEW! Ham Bootcamp Program – a hands-on activity to help folks get on the air and build their stations
  • Our Ham Expo Display featuring information and hands-on activities you can do with Amateur Radio
  • Kit Building Activity featuring a choice of two different kits
  • Multiple Get On The Air Stations including an HF Remote GOTA station and an on-site Satellite GOTA station
  • Special Event Station using the N1T Callsign
  • NEW! Radio Programming Station – Get your FM HT programmed with a custom repeater list for your location
  • Two Forum Presentations by Nashua Area Radio Society Members

The ARRL and the HamXposition team have been helping us to promote our activities. You can see what the ARRL is saying about our plans in their recent posting – Dayton Hamvention Radio Club of the Year to Hold Ham Bootcamp at New England Convention.

You can learn more about HamXposition and our activities there at the HamXpostion website.

Ham Bootcamp

A First HF Contact at Ham Bootcamp

We have created a program that we call Ham Bootcamp. Bootcamp to helps recently licensed and upgraded hams to get on the air. We are making this program available to up to 100 HamXpostion attendees on a first-come-first-served basis.

Our Bootcamp program will run from 9 am to noon on Saturday, September 7th in the Federal Room. Bootcamp will feature tracks for both Technician and General class license holders. It is also a great place for folks who are not yet licensed to learn more about Amateur Radio and how to get on the air.

Our Bootcamp program will include:

  • How to make a contact and join a repeater net
  • Putting together an HF station
  • Radio, antenna, and feed line choices
  • Getting started with FT8 and digital modes
  • Exchanging QSL cards
  • Learning Morse code
  • Tips on upgrading
  • Introduction to ham radio kit building
  • Handheld radio programming tutorials

Ham Bootcamp is free.  Participants will receive discount certificates for a kit build at the show and for purchase of Ham Radio Gear from Ham Radio Outlet.

You can learn more about Ham Bootcamp on the HamXposition website and on our website.

Source: Interest and Excitement Around HamXposition Is Building

I wanted to share our plans for several hands-on activities at HamXposition @ Boxboro in September. We hope that Ham Bootcamp will be of particular interest to folks getting into Amateur Radio. You can learn more about Ham Bootcamp and all of our planned activities via the link above. We hope to see some of our readers at HamXpostion next month!

Fred, AB1OC