High-Altitude Balloon Launch and Tracking


Our HAB at the Edge of Space (GoPro Capture)

Our HAB at the Edge of Space (GoPro Capture)

We made it to the edge of space! The image above was taken from our HAB at an altitude of over 90,000 ft!

After many months of work, raising funds to finance the project, teaching STEM sessions in local High Schools, and an open-house to test the Balloon Platform and to learn about Amateur Radio; our High-Altitude Balloon Project (HAB) Team finally got the chance to launch and track our Balloon. We launched our Balloon from the Elementary School in Winchester, NH.

Setting Up Our Gear

Setting Up Our Gear

Students, Teachers and Club Members came out to be part of the launch and to track our HAB. The first step was to move all of our gear to the center of the athletic fields at the school and organize all of our equipment.

Assembled Flight Platform

Assembled Flight Platform

Next, we attached the GoPro video cameras, satellite tracker and the battery pack for the Flight Computer and 2M APRS transmitter to the flight platform. We used an APRS capable HT to confirm that the flight computer and APRS transmitter were working.

Rigging the Flight Line

Rigging the Flight Line

We rigged the 40 ft. flight line which connected the HAB’s flight platform, recovery parachute and the balloon.

Balloon Inflation

Balloon Inflation

And then came the inflation of the balloon from the Helium tank. The winds were gusting to about 12 mph at this point which made inflating the balloon a little tricky. When filled, the balloon was about 6 ft. in diameter on the ground.

Launch!

Launch!

With both GoPro cameras running on the flight platform, we were ready to launch. A 10 second countdown and the balloon was up and away!

Tracking the HAB

Tracking the HAB

We watched the balloon from the ground as it soared off into the clouds. The 2M APRS tracking system worked perfectly and we spent the next several hours at the launch site, at lunch, and in our cars tracking the HAB on aprs.fi.

HAB’s Flight Path On APRS.fi

HAB’s Flight Path On APRS.fi

Our HAB’s flight path took it across Massachusetts where it reached a maximum altitude of 91,700 ft. above sea level (ASL).

Looking Upward at the Balloon (Near Burst)

Looking Upward at the Balloon (Near Burst)

The balloon reached a diameter of approximately 30 ft before it burst. After the balloon burst, the parachute deployed and the payload descended to a landing in the northeast corner of Rhode Island.

HAB at Recovery Site in Rhode Island

HAB at Recovery Site in Rhode Island

A combination of the APRS transmitter data and the on-board sounder allowed the landing location to be pinpointed and the flight platform recovered with help from a local resident.

The on-board GoPro video cameras captured some awesome video during our HAB’s ascent! All of the media captured by everyone who participated in the launch as well as the APRS data allowed us to produce the video above. Turn up your speakers and give it a play in full-screen mode to enjoy the experience what we shared!

By the time we had launched, school was at an end so we will have to wait until the fall to work with the students and teachers who were part of our STEM project to analyze the data from the flight. All in all, our HAB project has been an amazing experience for all involved. We are planning another HAB STEM experience and launch with additional schools in the fall.

We want to especially thank all of our donors whose generous contributions made this project possible.

Fred, AB1OC

 

An Amazing Amatuer Radio STEM Project – High-Altitude Balloon


Image Taken From Our High-Altitude Balloon at over 90,000 ft

Image Taken From Our High-Altitude Balloon at over 90,000 ft

Members of the Nashua Area Radio Club launched a High-Altitude Balloon (HAB) to the edge of space and back this past weekend. Our HAB carried a 2m APRS Transmitter and sent position and atmospheric telemetry to the ground during its flight. Our HAB was tracked by many folks using aprsi.fi during its flight via the N1FD-11 call sign.

You can see an amazing video of the flight include footage taken during our launch and from the balloon while in flight above.

Our HAB launch was part of a STEM learning project that our club did in partnership with several High Schools here in New Hampshire. You can read more about the project and our STEM work on our club’s Blog here.

Enjoy!

Fred, AB1OC
President, Nashua Area Radio Club

A Portable Satellite Station Part 2 – 2.0 Station Goals and Antenna System


M2 Antenna Systems LEO Pack On Display at Dayton 2016

M2 Antenna Systems LEO Pack on Display at Dayton 2016

We came upon the M2 Antenna Systems booth while walking around the exhibit halls at Dayton last year. M2 had one of their LEO Pack satellite antenna systems on display there. This got us thinking about building a new, more capable version of our portable satellite station. The LEO Pack is a relatively lightweight circularly polarized antenna system for working satellites using the 2 m and 70 cm bands. It turns out that AMSAT members can purchase the LEO Pack at a discount. Starting with the LEO Pack in mind, I began to lay out some goals for a new, 2.0 Portable Satellite Station:

  • Be capable of working all active Amateur LEO Satellites including those using linear transponders and digital modes
  • Be portable and manageable enough to be setup in an hour or less
  • Be simple enough to operate so that HAMs who are new to satellites can make all types of satellite contacts with a relatively short learning curve
  • Be manageable to transport and store
  • Utilize computer controlled antenna tracking to aim the antennas
  • Utilize computer control to manage radio VFOs to compensate for doppler shift
  • Be easy to transport and store
Computer Controlled Satellite Station Via MacDoppler

Computer Controlled Satellite Station via MacDoppler Software

We decided to take a computer controlled approach for both antenna aiming and Transceiver VFO management to meet our goal of making the station simple to operate for new satellite operators. After some research on the available options, we choose MacDoppler from Dog Park Software Ltd. for this purpose. MacDoppler runs under Mac OS/X and works well on our MacBook Air laptop computer which is very portable. This program also has broad support for many different rotator and transceiver platforms and is very easy to understand and use. Finally, the program features high quality graphics which should make the station more interesting to folks with limited or no experience operating through Amateur Satellites.

With the satellite tracking software chosen, we made selections for the other major components in the 2.0 Portable Satellite Station as follows:

I will explain these choices in more detail as our article series proceeds.

Glen Martin Roof Tower

Glen Martin 4.5′ Roof Tower

Our solution to making the antenna system portable is built around a Glen Martin 4.5′ Roof Tower. This short tower is a high-quality piece made of extruded aluminum parts. The tower is very sturdy when assembled and is light in weight. We added a pair of extended “feet” to the tower which are fabricated from 36″ x 2″ x 1 /4″ strap steel. This gives the tower a firm base to sit on and allows us to use sandbags to weight it down (more on this later).

Our chosen Yaesu G-500 AZ/EL Rotator is a relatively inexpensive Azimuth/Elevation rotator which is suitable for light-weight satellite antennas such as those in the LEO Pack. This rotator can be installed as a single unit on the top of a tower or separated using a mast. We choose the latter approach as it is mechanically more robust and helps to keep the center of gravity for our portable antenna system low for improved stability.

Yaesu G-5500 Elevation Rotator

Yaesu G-5500 Elevation Rotator

Separating the Yaesu AZ/EL rotator requires as short mast and a thrust bearing to be used. The mast was made from an 1-3/4″ O.D. piece of EMT tubing from our local hardware store. The thrust bearing is a Yaesu GS-065 unit. Both of these pieces fit nicely in the Glen Martin Tower. The thrust bearing provides support for the LEO Pack and G-500 elevation rotator and greatly reduces stress on the azimuth rotator. We also added a Yaesu GA-300 Shock Absorber Mount to the azimuth rotator. This part provides shock isolation for and reduces strain on the azimuth rotator during the frequent starts and stops which occur during satellite tracking.

LMR-400 Feed-lines And Antenna Connection Jumpers

LMR-400UF Feed-lines and Antenna Connection Jumpers

We decided to use LMR-400 UltraFlex coax throughout our antenna system. LMR-400UF coax provides a good balance between size, flexibility and loss for our application. To keep feed-line losses reasonable, we choose to limit the total length of the coax from the transceiver output to the antenna feed point to 50′. This results in a loss of about 1.3 dB on the 70 cm band. The result is that our planned IC-9100 Transceiver which has a maximum output of 75W on 70 cm will deliver a little more than 50W maximum at the feed point of the 70 cm yagi. This should be more that enough power to meet our station goals. Allowing a total of 15′ for antenna rotator loops and transceiver connections, we settled upon 35′ for the length of our coax feed-lines between the tower and the station control point.

Portable Tower Cable Connections and Base Straps

Portable Tower Cable Connections and Base Straps

We added some custom fabricated plates to the tower to act as a bulkhead for feed line and control cable connections and to mount our low-noise preamplifiers. The control connections for the rotators and preamps were made using 6-pin Weatherpack connectors and rotator control cable from DXEngineering. The control cables are also 35′ long to match the length of our coax feed lines. This length should allow the tower and the control point to be separated by a reasonable distance in portable setups.

Low-Noise Preamplifiers From Advanced Receiver Research

Low-Noise Preamplifiers from Advanced Receiver Research

We added tower-mounted Low-Noise Preamplifiers from Advanced Receiver Research to improve the receive sensitivity and noise figure for our satellite antenna system. Two preamps are used – one each for the 2 m and one for 70 cm antennas. While these units can be RF switched, we decided to include the preamp control lead in our control cable to allow for control of the preamp switching via sequencers. This was done to provide an extra measure of protection for the preamps.

Levels And Compass For Tower Setup

Levels and Compass for Tower Setup

We added a compass and pair of bubble levels to the tower assembly to make it easier to orient and level it during setup. This picture above also shows the Yaesu shock absorbing mount for the azimuth rotator.

Weight Bags To Anchor Portable Tower

Weight Bags to Anchor Portable Tower

Finally, we added a set of weight bags to securely anchor the tower when it is set up in a portable environment. These bags are filled with crushed stone and fasten to the legs of the Glen Martin tower with velcro straps.

LEO Pack Antenna Parts

LEO Pack Antenna Parts

With the tower and rotator elements complete, we turned our attention to the assembly of the M2 LEO Pack. The LEO pack consists of two circularly polarized yagis for the 2m and 70 cm bands. The 2m Yagi is an M2 Systems 2MCP8A which has 8 elements (4 horizontal and 4 vertical) and provides 9.2 dBic of forward gain. The 70 cm Yagi is an M2 Systems 436CP16 with 16 elements (8 horizontal and 8 vertical) and provides 13.3 dBic of forward gain. Both Yagi’s are meant to be rear mounted on an 8.5′ aluminum cross boom which is included in the LEO Pack. The picture above shows all of the parts for the two antennas before assembly. It took us about a 1/2 day to assemble and test the antennas and both produced the specified SWR performance when assembled and test in clear surroundings.

Assembled LEO Pack On Portable Tower

Assembled LEO Pack on Portable Tower

The picture above shows the assembled LEO pack on the portable tower. We attached a short 28″ piece of mast material to the cross boom as a counterweight to provide better overall balance and to minimize strain on the elevation rotator. The antennas and the two outer sections of the mast can be easily removed to transport the antenna system.

2m Circularly Polarized Yagi Feed Point

2m Circularly Polarized Yagi Feed Point

The LEO Pack yagis achieve circular polarization via a matching network which drives the vertical and horizontal sections of the antennas with a 90 degree phase shift. The phase shift (and a final 50 ohm match) is achieved using 1/4 wave delay lines made of coax cables. We configured our antennas for right-hand circular polarization. The choice between right and left hand circular polarization is not a critical one in our LEO satellite application as most LEO satellites are not circularly polarized. The advantage of circular polarization in our application is the minimization of spin fading effects.

Green Heron RT-21 Az/El Rotator Controller

Green Heron RT-21 AZ/EL Rotator Controller

The final step in the construction of our antenna system was to add the rotator controller and test the computer aiming system. We have had very good results using Green Heron Engineering rotator controllers in our home station so we selected their RT-21 AZ/EL rotator controller for this application. The RT-21 AZ/EL rotator controller is really two rotator controllers in a single box. The rotator control parameters such as minimum and maximum rotator speed, ramp, offset, over travel and others can be independently set for each rotator.

Rotator Test Using MacDoppler

Rotator Test Using MacDoppler

The RT-21 AZ/EL Rotator Controller connects to our computer via a pair of USB cables. We run Green Heron’s GH Tracker software on our MacBook Air laptop to manage the computer side of the rotator controller and to provide a UDP protocol interface to the MacDoppler tracking software. The picture above shows the test setup used to verify the computer controlled antenna pointing system.

Mixed OS/X and Windows Software Environment

Mixed OS/X and Windows Software Environment

One challenge associated with selecting a Mac OS/X platform for computer control is what to do about the inevitable need to run Windows software as part of the system. In addition to the GH Tracker software, the WaveNode WN-2 Wattmeter and digital modem software for satellite/ISS APRS and other applications require a Windows run-time environment. To solve this problem, we use a virtual machine environment implemented using VMware Fusion and Windows 10 64-bit on our MacBook Air Laptop along with Mac OS/X. Using the Unity feature of VMware Fusion allows us to run windows apps such as GH Tracker as if they were native Mac OS/X apps. The picture above shows an example of this.

Rotator Controller and Software Configuration

Rotator Controller and Software Configuration

With the antennas removed from the cross boom, we tested the operation of the computer controlled tracking system. The Yaesu G-5500 AZ/EL Rotator have some limits as to its pointing accuracy and backlash performance.  Experimentation with the combination of  the RT-21 AZ/EL rotator controller, GH Tracker and MacDoppler setups was required to achieve smooth overall operation. We finally settled on a strategy of “lead the duck” tracking. The idea here is to set up the rotators so that they over-travel by a degree or so when the computer adjusts them and couple this with a relatively wide 2-3 degree tracking resolution. This maximizes the overall accuracy of the pointing system and minimizes the tendency towards constant start-stop operation of the rotators during satellite tracking. Our current configuration for all of the elements involved in the tracking system is shown above.

With the antenna system complete and tested, we can move onto the next step in our project – the construction of a computer controlled transceiver system. We will cover this element in the next part  in this series. Other articles in the series include:

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

Fred, AB1OC

A STEM Learning Project for Young People


High Altitude Balloon At The Edge Of Space

High Altitude Balloon At The Edge Of Space

As some of you may already know, Anita and I have been working with our local Radio Club on a project to promote STEM learning and interest in Amateur Radio among young people in our area. The idea is to work with kids grades 7-12 to plan, build, launch and recover a High-Altitude Balloon carrying Amateur Radio. Our balloon should be able to reach an altitude of about 100,000 ft before it bursts and the payload returns to earth via a parachute system. The payload will include a computer, GPS and a 2 meter APRS transmitter to record the balloon’s flight track, atmospheric data and altitude throughout the flight. The balloon will also carry a video camera and will capture a video record of the entire flight. You can learn more about our project here.

Project Team Members Will Analyze and Report On Scientific Data

Project Team Members Will Analyze and Report On Scientific Data

We are working with local schools to put together a team of young people to plan and execute our project. This will include designing the on-board science experiments, analyzing the data collected and providing a presentation about what was learned to fellow students and others who are interested.

You can learn more about our project and view a video that shows what our balloon flight will be like on our Club website. This project is part of our Club’s on-going program to promote interest in Amateur Radio among young people. The folks at HAMNation recently featured a video which included some information about our club’s activities for young people as well.

We are working to raise the necessary funds to enable the project to be completed during the current school year. We have setup a GoFundMe page to facilitate the fund raising aspect of our project. We know that we have many readers around the world who follow our blog and it would be wonderful if some of our readers could help us by contributing to funding our project.

Anita and I will continue to post information about our project here.

Best and 73,

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)

Amateur Radio Station Design And Construction


Station Design And Construction

Station Design And Construction

A little ways back, John (W1MBG) discovered our Blog and approached us about doing a presentation for the Nashua Area Radio Club (NARC) on the design, construction and operation of our recently completed station. The NARC group invited us to their March meeting where we shared our presentation with the nice group of folks in the Club. I wanted to post an overview of what we shared as well as a link to the full presentation so that our readers can have a look at the material and hopefully benefit from the information that we have assembled. I have also used this post as an opportunity to create an index to all of the articles on this Blog related to the design, construction and performance of our station.

Topics Covered

Topics Covered

Our new station project involved both the construction of a dedicated room for a new shack and a tower based antenna system. It took us about 1 1/2 years to build our station including the associated antenna system and we covered quite a number of areas during the project. Our presentation focused on some things that we did to plan and build our station that should be useful to many Hams building or upgrading anything from a simple station to an all out effort to create a state of the art multi-op station.

Station Goals

Station Goals

I think that its important to begin a new or upgrade station project by thinking through and writing down the goals that you have for your new station prior to purchasing equipment or beginning construction. This step is important because it helps you to think through what you want to accomplish and serves as a high-level blueprint for making design, equipment selection and construction decisions as you build your station.

Shack Layout

Shack Layout

We put considerable time and thought into the design of the room and operating area for our new shack including many rounds of drawings and some “human engineering” to arrive at the final room layout. While not every Ham will build a dedicated room for their shack, some careful thought put into the layout of the operating and storage areas for your shack and the associated support systems is an important design step.

Antenna System Planning

Antenna System Planning

The other major element in the design of our station was a new tower-based antenna system. We had some pretty expansive goals for the band capabilities and associated performance of our new antenna system and the presentation explains how we went about developing and executing a plan to meet our goals.

Additional Antenna Construction

Additional Antenna Construction

Since the initial installation of our tower antenna system, we added an 8-Circle Vertical Receive Array for the Low Bands and we’ve reinstalled our SteppIR BigIR Vertical Antenna. These new antenna system provide important additional performance on the low bands and during contests. We’ve also added an Antenna System and Electronics for LEO Satellites.

Station Automation

Station Automation

We’ve also installed an SO2R and Station Automation System from microHAM. The microHAM system enables much smooth and less error-prone operation of our station and enable SO2R and Multi-two operation during contests.

Virtual Station Tour

Virtual Station Tour

Our presentation includes several slides which cover the construction of our new shack and tower as well as the feedline, antenna, power and other supporting systems. The end result of all of this work is shown via a few slides which provide a “Virtual Tour” of our station.

Virtual Station Tour - Operational Videos

Virtual Station Tour – Operational Videos

The “Virtual Station Tour” slides contain several videos which can be played by clicking on the following links:

Other posts in this Blog contain more detailed information and many additional pictures and videos about our station. See the index of links at the end of this post to view more detail about the areas that interest you.

Station Performance

Station Performance

Our new station has been complete for several months now and we wanted to take some time to look at how it is performing against our original design goals. As you can see from the above slide, we are on a good track to meet or exceed all of the original goals that we set during the planning stage of our project.

What We Learned

What We Learned

Finally, we shared some additional information about what we learned during the project and a set of links to various sources of equipment and information that we used to complete our new station (see the full presentation). This Blog contains many more details (and pictures) about the design and construction of our station for those who are interested. Some good places to begin are categorized in the index of links below:

Shack Design and Construction:

Antenna and Tower Design:

Tower Construction:

Antenna Construction:

Tower Integration:

Station Integration:

Station Operation and Performance:

I hope that you can apply some of the ideas and information shared here to building or improving your station. We’d also like to extend a special thanks to John, W1MBG and the NARC Group for encouraging us to create and share this presentation. We are available to provide this presentation to other clubs or Ham gatherings. If your club or event is interested, please contact us at ab1oc@arrl.org.

Fred (AB1OC)

APRS Station Part 2 – Dedicated Antenna and Always-On PC


APRS Station Setup

APRS Station

We have had our APRS Station operating for a while now and it has been performing well. We decided to install a dedicated antenna on our tower that is a bit better matched to supporting our APRS Station. We choose a Diamond X50NA antenna and installed it on our tower at the 70 ft level using a vertical antenna bracket. The Diamond X50NA antenna has a broader vertical pattern than out existing repeater access antenna (a Diamond X300NA). The Diamond X50NA antenna is installed 19″ from the tower leg to minimize any interactions with the tower structure on the 2m band.

APRS Antenna On Tower

APRS Antenna On Tower

I also decided to move our APRSISCE/32 Software which controls our APRS Station to our home server which is always on.

Home Server

Home Server

The APRSISCE/32 software implements an iGate function (sending APRS packets to internet-based APRS servers) so it performs a critical role as part of our APRS Station’s operation. The following is a time-lapse video which shows about 6 minutes of the APRSISCE/32 software’s operation. The yellow lines show the paths taken by packets through various APRS Digipeaters on their way to the internet via our iGate. The circle on the map in the video is about 180 mi (290 km) in diameter. As you can see in the video, we are handing packets from New Hampshire, USA as well as from several surrounding states in New England. It is interesting to see the paths that some APRS packets follow as they find their way to the internet via our iGate node. It is quite apparent when there is an improvement in 2m propagation as we begin to see packets arriving from much greater distances.

The connection between our APRS transceiver (a Kenwood D-710A) and our home server is implemented via an RS-232 over TCP/IP device from StarTech. This device allows us to run the RS-232 control connection from the APRS transceiver to our home server over the wired Ethernet LAN installed in our home.

RS2323 Over TCP/IP Device

RS232 Over TCP/IP Device

With these steps, our APRS Station is complete. We are currently iGate’ing about 7,500 packets per month to the internet. You can see some real-time information on the performance of our station by clicking here.

– Fred (AB1OC)