An 80m Broadband Matching System

January 28, 2018 by fkemmerer

Our Tower with 75m Loop

We installed a 75m loop for SSB operation on our tower when we built it. The loop is full size and is diamond shaped so that our lower SteppIR DB36 yagi can rotate inside of it. The loop is fed at the bottom corner about 20 ft up from the ground. It works great for SSB operation on 75m but we have often wished we could use it across the entire 80m band. This goal led to a project to create a matching system for the antenna. The idea was to use a set of loading coils in series at the feed point create a good match in all segments of the 80m band.

EZ-NEC Model for 75m Loop

The first step in the design of our 80m matching system was to build a model of our current loop using EZ-NEC. The model was then used to determine the correct values of a set of series loading inductors to match different segments of the 80m band.

Matching System Design Analysis

We also considered how likely different segments of the 80m band were to be used by profiling historical spotting data from DXSummit. All of this analysis led to the creation of a final design which is captured in the spreadsheet shown above. The final design requires our current 75m loop to be shortened a bit to work well at the very top of the 80m band.

Modeled Loading Coil Inductance Values

A set of 5 different inductor pairs can be used in series with the loop’s feed point to create a good match across the entire 80m band. The modeled values for the series matching inductors is shown above.

Matching System Modeled SWR

Our microHAM control system can easily implement the switching of the various inductance values based upon the frequency that a radio using the antenna is tuned to. Result modeled SWR for the final 80m loop and match combination is shown above. The design should achieve an SWR < 1.5:1 across the entire 80m band except for the very top where the SWR remains < 2:1. Also, the design optimizes the system’s SWR in the important CW DX, SSB DX, and Digital windows on the 80m band.

Layout of Components in Enclosure

With the design completed, we choose an enclosure and all of the components. Here are the details of what we used:

Barker and Williamson 2404TL 32 uH Airdux coil stock cut in half (3″ dia, 4 TPI)
Array Solutions RF-15 15/20 kW RF Relays
Balun Designs 1.5:1 Balun with eyelets
V22ZA2P Varistors (MOVs), 0.1 uF Capacitors, 1N4001 Diodes make up the 12Vdc relay control circuits
Outdoor NEMA Box Approx. 16″x12″x6.5″
DX Engineering Saddle Clamps to fit our tower

The first step in the construction was to layout all of the components in the enclosure. Attention was paid to keeping the two series inductors at right angles to avoid coupling and to keep RF connections as short as possible. The relays were arranged to keep the leads connecting to the coils of roughly equal length. Finally, the control circuitry was kept as far removed from the RF leads as possible.

Enclosure Mounting Ears and Clamps

The matching system attaches to a tower leg via saddle clamps. We fabricated a set of mounting ears and spacer blocks to position the enclosure far enough away from the tower so that the antenna connections do not interact with the tower.

80m Matching System Construction

A summary of the completed matching system construction is shown above.The design uses a set of four double-pole double-throw relays to switch in different coil taps which selects the loading inductance provided by the matching system.

We did a set of calculations and found that our relays would be subjected to a worst case peak-peak voltage of about 2.1 KVp-p at the coil tap points.

The relays are arranged such that two sets of contacts have to be traversed to select any given coil tap. The relays we are using have a third pole which we are not using. We disassembled each relay and removed the internal contact wiring for the center pole which improves both the coil to contact voltage rating and the isolation values of the relays.

These steps combine to improve the voltage rating of the system. This is an important design element given that the match will operate at legal limit power.

Completed RF Deck

The completed RF deck and control circuitry is shown above. The enclosure we choose came with a removable plastic plate that made mounting and wiring all of the components simple.

Loading Coil Mounting and Taps

The loading inductors are mounted using nylon hardware with the ends connected to the two antenna terminals on the sides of the enclosure. The coils use movable tap clips to allow us to fine-tune the match once the system is installed with the antenna on our tower. The initial clip locations are set to create the inductance values modeled during the design phase.

Relay Control Circuit Connections

The relay control leads use twisted pair wiring to minimize RF pickup. The control leads are routed away from the RF connections to minimize potential RF coupling.

Relay Control Circuit Details

The control circuits for each relay use a combination of a Diode, a Varistor (MOV) and a filter capacitor in parallel to avoid relay coil switching interference and to suppress control line noise.

1.5 to 1 Matching Balun

The matching system is designed to operate at 75-ohms which is pretty close to the resonant impedance of our 75m loop. The current antenna uses a 1.5:1 Balun to match the loop to our 50-ohm coax feedline. We disassembled an identical matching balun (actually a 75-ohm balun plus a 1.5:1 unun) and used it without its enclosure to create a final 50-ohm match.

MicroHAM Setup to Control 80m Matching System

The final step in the construction of our matching system was to program our microHAM antenna switching system to properly configure the relays in our matching system. This was quite simple to do using microHAM’s frequency dependent antenna control capabilities. The microHAM system automatically operates the appropriate relays to create the best possible match as the radio which is using the matching system is tuned across the 80m band.

Unfortunately, we are in the middle of winter here in New England so I will have to wait for warmer weather to install our new matching system on the tower and make the final adjustments. I am planning another article here when the final integration steps are done to cover the performance of the completed project.

Fred, AB1OC

A Portable Satellite Station Part 4 – 2.0 Station First Contacts!

March 3, 2017 by fkemmerer

Station Packed and Ready for Transport

With our new 2.0 Satellite station built, tested, and packed; we were ready to try it in a portable environment. Fortunately, the Nashua Area Radio Club had a Technician License class coming up and we thought that the new station test would be a great way for our students to learn about Amateur Radio Satellites.

Satellite Status from AMSAT Website

Final preparations included checking the operational status of potential satellites on the AMSAT website. The page shown above is like a spotting cluster for LEO Satellites – it shows satellite activity as reported by HAM satellite operators. Using this information, we configured MacDoppler to track the active satellites.

Satellite Pass Predictions

Next, we used MacDoppler to generate pass predicts for the weekend of our Technical Class. We assembled this data for all of the potential satellites and color-coded the available passes to identify those which had the best chance of producing contacts.

With this done, we loaded our portable tower, antennas, and all of the rest of the gear into our pickup truck and transported it to the class site.

Satellite Antennas Setup Portable

The first step at the class site was to unload all of our gear and move the portable tower to a suitable location. We used a compass to orient the tower to true north and leveled it. We used the weight bags that we made up to anchor the tower securely and then installed the antennas, rotator loops, and control cables. The antenna system worked out very well in the portable environment and was easy to set up.

Satellite Antenna Details

Here’s a closer to look at the LMR-400 UF coax cables which connect the antennas to the rest of the system. The loops just behind the antennas are necessary to keep the coax from affecting the pattern of the antennas. The coax cables shown were made long enough to allow the antennas to be rotated through their full travel in the azimuth and elevation directions without binding.

Satellite Station Portable – Radio and Supporting Equipment

The final step in the portable setup was to put the IC-9100 Transceiver and Supporting Equipment together in the building and check everything out. As soon as we got everything hooked up and working, we heard an ON4 station through FO-29 which was near the end of a low angle pass. A very good sign!

We took some time to fine-tune the calibration of our rotators and to check the operation of the computer controls – everything checked out fine. The video above shows MacDoppler controlling the Azimuth/Elevation rotator and the IC-9100 Transceiver during the testing.

First Contact using New 2.0 Station (AO-85)

First Contact using New 2.0 Station (via AO-85)

With all the setup done, it was time to try to make our first contact. Fortunately, we did not have long to wait. We caught a medium angle pass of AO-85, a U/V Mode FM Easy Sat. With MacDoppler setup and tacking, we immediately heard contacts being made through AO-85. I gave a whistle and adjusted my uplink VFO until I heard my signal coming back through AO-85. I gave a quick CQ call and immediately got a response from Jonathan, NS4L in Virginia, USA! It took on a few seconds to exchange call signs and grid squares and our first contract with our new station was in the log.

Explaining Satellite System to License Class

Our Technician License Class students were very interested in the station. We spent some time explaining the setup and demonstrating how it worked. We made more contacts between our class sessions using AO-85 and FO-29 (a V/U Mode Linear Transponder Satellite). Our most interesting contact was with Burt, FG8OJ in Guadeloupe through FO-29. It was great to work DX using the new station during the first time we used it.

We learned several things during our first use of the new station. First, while the 35 ft. maximum separation allowed between the antenna system and the rest of the station is adequate in many applications, the antenna system’s close proximity to the building we were in blocked passes to the west of us with this separation. We have subsequently made up an additional set of feed lines using a pair of 100 ft. long 7/8″ hardline coax cables to allow for a greater separation in portable deployments such as this one.

We were glad that we had the Heil Pro 7 Headset with us and we used it for most of our contacts. The separate speaker allowed our students to hear the contacts well and the boom microphone on the Pro 7 Headset eliminated feedback due to our own voice coming back through the satellites. We improvised a mono to stereo converter cable to connect the Heil Pro 7 Headset to one of the two speaker outputs on the IC-9100 Transceiver. This allowed the radio to drive the separate speaker and the headphones at the same time.

We were glad to have the low-noise preamps available. These were especially useful during low-angle satellite passes and the sequencing setup that we built worked well.

All in all, the first test of our new 2.0 Portable Satellite station was a success. Our license classes students enjoyed learning about Amateur Satellites and had fun along with us making contacts through a few of them. Our next goal will be to get packet modes and APRS working with our setup. We plan to do another article in this series when this part of our project is completed. Other articles in this series include:

We are planning to add larger antennas and switchable polarity to our portable satellite station in the near future. This will enable us to make contacts with Satellites and the ISS in more difficult conditions.

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

Fred, AB1OC

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

February 22, 2017 by fkemmerer

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 set up 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 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:

Glen Martin RT-424 4.5′ Roof Tower to mount all of the antenna system components for portable operation
M2 Antenna Systems LEO Pack Antennas and Hardware
Yaesu G-5500 AZ/EL Rotator
Green Heron RT-21 AZ/EL Rotator Controller
Advanced Receiver Research Low-Noise Preamplifiers for 2m and 70 cm
S3 Sequencers from M2 Antenna Systems for preamplifier control
LMR-400UF Coax for feed-lines
MacDoppler Satellite Tracking software from Dog Park Software
Icom IC-9100 Transceiver
WaveNode WN-2 Wattmeter

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

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

Separating the Yaesu AZ/EL rotator requires a 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-3000 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 than 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

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

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

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

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

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

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

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

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

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

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

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 were 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 the 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

Fall Antenna Projects – A New Low-Band Receive Antenna System

November 27, 2016 by fkemmerer

NCC-1 Receive Antenna System Control Unit and Filters

Anita and I like to take advantage of the mild fall weather to do antenna projects at our QTH. We have completed two such projects this fall – the installation of a Two-Element Phased Receive System and a rebuild of the control cable interconnect system at the base of our tower.

NCC-1 Receive Antenna System Components

Our first project was the installation of a DXEngineering NCC-1 Receive Antenna System. This system uses two receive-only active vertical antennas to create a steerable receive antenna system. The combination can work on any band from 160m up to 10m. We set ours up for operation on the 80m and 160m bands.

NCC-1 Receive System Antenna Pattern

The NCC-1 System can be used to peak or null a specific incoming signal. It can also be applied to a noise source to null it out. The direction that it peaks or nulls in is determined by changing the phase relationship between the two Active Antenna Elements via the NCC-1 Controller.

NCC-1 Filter Installation

The first step in the project was to open the NCC-1 Control Unit to install a set of 80m and 160m bandpass filter boards. These filters prevent strong out-of-band signals (such as local AM radio stations) from overloading the NCC-1. The internal switches were also set to configure the NCC-1 to provide power from an external source to the receive antenna elements through the connecting coax cables.

Installed Active Receive Antenna Element

The next step in the project was to select a suitable location for installing the Receive Antenna Elements. We choose a spot on a ridge which allowed the two Antenna Elements to be separated by 135 ft (for operation on 160m/80m) and which provided a favorable orientation toward both Europe and Japan. The antenna elements use active circuitry to provide uniform phase performance between each element’s 8 1/2 foot whip antenna and the rest of the system. The antenna elements should be separated by a 1/2 wavelength or more on the lowest band of operation from any towers or transmit antennas to enable the best possible noise rejection performance.

Received Antenna Element Closeup

The two Antenna Elements were assembled and installed on 5 ft rods which were driven into the ground. To ensure a good ground for the elements and to improve their sensitivity, we opted to install 4 radials on each antenna (the black wires coming from the bottom of the unit in the picture above). The Antenna Elements are powered through 75-ohm flooded coax cables which connect them to the NCC-1 Control Unit in our shack. The coax cable connections in our setup are quite long – the longer coax of the pair being approximately 500 ft. The use of flooded coax cable allows the cables to be run underground or buried. Should the outer jacket become nicked, the flooding glue inside the cable will seal the damage and keep water out of the cable.

Receive RF Choke

It is also important to isolate the connecting coax cables from picking up strong signals from nearby AM Radio stations, etc. To help with this, we installed Receive RF Chokes in each of the two coax cables which connect the Antenna Elements to the NCC-1. These chokes need to be installed on ground rods near the Antenna Elements for best performance.

Underground Cable Conduit In Our Yard

We ran the coax cables underground inside cable conduits for a good portion of the run between the antenna elements and our shack. The conduits were installed in our yard when we built our tower a few years back so getting the coax cables to our shack was relatively easy.

Receive Antenna Coax Ground System

The last step in the outdoor part of this project was to install a pair of 75-ohm coax surge protectors near the entry to our shack. An additional ground rod was driven for this purpose and was bonded to the rest of our station’s ground system. We routed both of the 75-ohm coax cables from the two Antenna Elements through surge protectors and into our shack. Alpha-Delta makes the copper ground rod bracket shown in the picture for mounting the surge protectors on the ground rod.

Antenna Equipment Shelf In Our Shack (The NCC-1 Control Unit Is At The Bottom)

The installation work in our shack began with the construction of a larger shelf to hold all of our antenna control equipment and to make space for the NCC-1. The two incoming coax cables from the Antenna Elements were connected to the NCC-1.

microHAM Station Master Deluxe Antenna Controller

Antenna switching and control in our station is handled by a microHAM System. Each radio has a dedicated microHAM Station Master Deluxe Antenna Controller which can be used to select separate transmit and receive antenna for the associated radio. The microHAM system allows our new Receive Antenna System to be shared between the 5 radios in our station.

Antenna Switching Matrix

The first step in integrating the Receive Antenna System was to connect the output of the NCC-1 to the Antenna Switching Matrix outside our shack. We added a low-noise pre-amp (shown in the upper left of the picture above) to increase the sensitivity of the Antenna System. The blue device in the picture is a 75-ohm to 50-ohm matching transformer which matches the NCC-1’s 75-ohm output to our 50-ohm radios. The other two pre-amps and transformers in the picture are part of our previously installed 8-Circle Receive Antenna System.

Multi-Radio Sequencer

The Antenna Elements must be protected from overload and damage from strong nearly RF fields from our transmit antennas. In a single radio station, this can be handled via a simple sequencer unit associated with one’s radio. In a multi-op station such as ours, it is possible for a different radio than the one which is using the Receive Antenna System to be transmitting on a band which would damage the Receive Antenna System. To solve this problem, we built a multi-radio sequencer using one of the microHAM control boxes in our station. The 062 Relay Unit shown above has one relay associated with each of the five radios in our station. The power to the Receive Antenna System is routed through all 5 of these relays. When any radio transmits on a band that could damage the Antenna Elements, the associated relay is automatically opened 25 mS before the radio is allowed to key up which ensures that the system’s Antenna Elements are safely powered down and grounded.

Updated microHam Antenna System Diagram

With all of the coax and control connections complete, I was able to update the microHam system design information for our station and add the new receive antenna system to our setup. You can find more about the programming of our microHam system here.

NCC-1 Controls

So how well does the system work? To test it, we adjusted the NCC-1 to peak and then null a weak CW signal on 80m. This is done by first adjusting the Balance and Attenuator controls on the NCC-1 so that the incoming signal is heard at the same level by both Antenna Elements. Next, the B Phase switch is set to Rev to cause the system to operate in a signal null’ing configuration and the Phase control is adjusted to maximize the nulling effect on the target signal. One can go back and forth a few times between the Balance and Phase controls to get the best possible null. Finally, the incoming signal is peaked by setting the B Phase switch to Norm.

Peaked And Null’ed CW Signal

The picture above shows the display of the target CW signal on the radio using the NCC-1 Antenna System. If you look closely at the lower display in the figure (null’ed signal) you can still see the faint CW trace on the pan adapter. The difference between the peak and the null is about 3 S-units or 18 dB.

NCC-1 Used For Noise Cancellation

The NCC-1 can also be used to reduce (null out) background noise. The picture above shows the result of doing this for an incoming SSB signal on 75m. The system display at the top shows an S5 SSB signal in the presence of S4 – S5 noise (the lower display in the picture). Note how clean the noise floor for the received SSB signal becomes when the unit is set to null the noise source which comes from a different direction than the received SSB signal.

We are very pleased with the performance of our new Receive Antenna System. It should make a great tool for DX’ing on the low-bands. It is a good complement to our 8-circle steerable receive system which we use for contesting on 160m and 80m.

Tower Control Cable Interconnects (Bottom Two Gray Boxes)

Our other antenna project was a maintenance one. We have quite a number of control leads going to our tower. When we built our station, we placed surge protectors at the base of our tower and routed all of our control leads through exposed connections on these units. Over time, we found that surge protection was not necessary and we also became concerned about the effects that sunlight and weather were having on the exposed connections. To clean all of this up, we installed two DXEngineering Interconnect Enclosures on our tower and moved all the control cable connections inside them.

Inside View Of Interconnect Enclosures

We began with a pair of enclosures from DXEngineering and we mounted screw terminal barrier strips on the aluminum mounting plates in each enclosure. The aluminum plates are grounded via copper strap material to our tower.

Closer Look At One Of The Interconnect Enclosures

The picture above shows one of the interconnection boxes. This one is used to connect our two SteppIR DB36 Yagi Antennas and some of the supporting equipment. The barrier strips form a convenient set of test points for troubleshooting any problems with our equipment on the tower. There are almost 100 control leads passing through the two enclosures and this arrangement keeps everything organized and protected from the weather.

With all of our antenna projects complete, we are looking forward to a fun winter of contesting and low-band DX’ing.

73,

Fred, AB1OC

Summertime Station and Antenna Projects At AB1OC/AB1QB

August 14, 2016 by fkemmerer

Summer is the time of year that many of us work on our antennas and improve our stations. Anita AB1QB and I did both of these things at our QTH this summer.

Removing Lower SteppIR Yagi From Tower

Our SteppIR DB36 Yagis were due for some maintenance so we took them off our tower. A special thanks to all the members of the Nashua Area Radio Club who helped us remove, recondition and reinstall our antennas! Matt Strelow, KC1XX of XX Towers and Andrew Toth provided equipment and know how to safely remove our two large SteppIR DB36 Yagis with help from the rest of us.

Lowering Antenna With Electric Winch

The SteppIR DB36 Yagis weigh almost 200 lbs each and Matt made good use of his electric winch to lower them.

Antenna Coming Down The Tram Line

The picture above shows the lower antenna coming off the tower. We used a Tram Line system to lower both antennas to the ground so that we could rebuild them.

SteppIR DB36 Antenna On The Ground

The SteppIR DB36 Yagis are quite large. They have 36 ft booms and the driven elements are almost 50 ft from tip to tip! They completely fill up our back yard when they are both off the tower.

Element Pole Sun Damage

The rebuild process began with a careful inspection of both antennas. They were both in good overall condition with some sun damage to the paint on the fiberglass element poles.

Disassembled SteppIR DB36

We removed all the element tubes and sweeps from both antennas for rebuilding. The picture above shows the disassembled upper antenna.

Reconditioned Stepper Motors Installed

All four Stepper motors on both antenna were replaced. These motors move metal tapes inside hollow element tubes to adjust the length of each antenna’s 4 movable elements. These adjustments are done automatically by controllers in our shack which receive frequency information from the radios which are connected to each antenna.

Reconditioned Element Sweep Poles

All of the element housing poles were cleaned, prepped and painted with a UV resistant clear coat to protect them from further sun damage. The poles cleaned up like new.

New Element Sweeps Ready For Installation

The assembly of all the new element sweep tubes (shown above) was done next. Each antenna has six sweeps.

Element Pole Preparation

The end of each element pole must be prepped with a tape system which ensures that the poles are seated properly, sealed to and firmly attached to the sweeps. This process and the associated assembly and tightening of the element couplers was the most time-consuming step in the rebuild process as it had to be repeated a total of 24 times.

Rebuilt Element Assembly

Here’s a picture of one of the rebuilt element tube assemblies. The ropes support the element tubes and keep them aligned when the antenna is up in the air. These elements are attached to the antenna motors with couplers and clamps.

SteppIR DB36 Yagi – Rebuild Complete

The picture above shows the lower antenna with all the element tubes reattached. There is quite a bit of additional prep work associated with adjusting all the supports and taping all the exposed areas of the antennas which are susceptible to sun damage. Also, all the electrical wiring on the antenna must be checked to ensure good electrical connections and good overall condition of the wiring.

Ground Test Setup

The final step in rebuilding the antennas is to test their operation on the ground. This ground test is done to ensure that all the motors are working correctly and that the element tapes move smoothly inside the rebuilt element tubes.

Ground Test Results

Another important part of the antenna Ground Test is to confirm that the antennas have a consistent resonant frequency and SWR on all bands. The resonant frequencies and SWR levels are far from those that would be measured when the antennas are on the tower at operating height. The idea here is to confirm that a resonance exists and that its frequency and SWR readings are repeatable as the antenna is adjusted to different bands.

With both antennas rebuilt, its was time for Matt and Andrew to return and, with help from folks from our club, reinstall the rebuilt antennas on our tower. The video above shows this process. It is quite something to see! The installation took about 3 1/2 hours.

Updated SteppIR Controllers

The last step in the SteppIR DB36 rebuild process was to install the latest firmware in the associated SDA100 Antenna Controllers. There are some integration issues between the updated SteppIR Firmware and our microHAM system but we are getting those worked out with help from the folks at both SteppIR and microHAM.

Icom IC-7851 With Display Monitor

I recently had a major birthday milestone and Anita surprised me with a new radio – an Icom IC-7851. This radio is an upgrade/replacement for our Icom IC-7800. While the two radios are quite similar in their operation and interfaces, I did not want to install the IC-7851 until the SteppIR antennas were reinstalled and all of their upgrades were working properly with our current radios. With the antennas done, it was the finally time to install the new radio!

Icom C-7851 Transceiver

The Icom IC-7851 has several important performance upgrades. The most impactful one is a new low phase noise oscillator which significantly improves RMDR performance compared to the IC-7800. The IC-7851 is in the top-tier of Transceivers in Sherwood Engineering’s tests. The receivers in the IC-7851 are very quiet, have excellent Dynamic Range and perform great in when close-in interference is present.

Icom IC-7851 Display Monitor

The Icom IC-7851 has a higher resolution and faster display. It also supports higher resolution external monitors so we installed am upgraded display monitor along with the new radio. The IC-7851 has a number of new networking features and supports stand-alone remote operation over a LAN and the Internet. We are planning to use these capabilities to add a second remote operating gateway to our station. More on this in a future article.

The combination of the rebuilt antennas and the new IC-7851 Transceiver has our station performing better than ever. The antennas are working as well or better than when they were new and the IC-7851 has significantly better receive performance compared to its predecessor and is a pleasure to use.

We will be hosting the ARRL Rookie Roundup RTTY contest for our club members who have received their first license in the last 3 years next weekend and we’re going to use the new radio and rebuilt antennas for the contest.

This project was completed in a little over two weeks and was a lot of work. I could not have done the project without the help of the many folks in the Nashua Area Radio Club. Again, a big Thank You to all the folks in our club who helped me with this project! I hope that many of you will be able to find some time to operate from our upgraded station.

73,

Fred, AB1OC

2015 Nashua Area Radio Club Field Day Recap

August 21, 2015 by fkemmerer

We had the opportunity to be part of the Nashua Area Radio Club’s 2015 Field Day Operation. Ed, K2TE was our incident commander and he helped to club to put together a great Field Day Operation. We operated under our club callsign, N1FD as 8A. John, W1MBG put together the video above which is a really nice recap of our operation.

Field Day Tower and Beams

The club was very active in WRTC 2014 and, as a result, was able to purchase several of the tower and station kits from the WRTC operation. The heart of our Field Day antenna system was built around two of these towers. One was used for CW and 6m and the other was used for SSB. Both towers had tri-band beams and we used Triplexers and Filters to allow our stations on 20m, 15m and 10m to share the beams on each tower. The towers got us a long way towards our status as an 8A operation.

Wire Antenna Construction

My role in the setup part of our Field Day operation was to build our wire antennas. We began with a class covering how to build and tune Delta Loop antennas and we used the newly gained information from our class to build 40m and 80m delta loops at our Field Day site. We also put up a 75m inverted-V antenna in one of the tall trees at our site.

Operating Tents

We made good use of our WRTC station kits and other gear that our members brought to setup comfortable tents to operate from as well as a public information tent and a food tent.

Some Of Our Operators For The Nashua Area Radio Club

Despite the rainy weather on Saturday evening and Sunday, we all stayed comfortable and dry. Shown above is Dave, N1RF, Mike, K1WVO and Mike, K1HIF in our 40m SSB tent.

Field Day 20m SSB Station

John, W1MBG and I shared a tent which we used for both 10m and 20m SSB operations. The picture above shows our 20m station which was built around an Elecraft KX3 with a PX3 Panadapter and 100w outboard amplifier.

Mikayla Operating With Her Dad During Field Day

Our club has been doing a great deal of work on bringing young people and other new HAMs into the hobby via license classes, outreach to schools and other activities. We carried this work into our Field Day operations with a GOTA station and lots of opportunities for new HAMs and young people to get on the air. Shown above is Wayne, AA9DY helping his daughter Mikayla to make some contacts on 20m SSB phone.

Field Day Feast

Anita, AB1QB made us great meals and snacks during our Field Day operation. The food provided all of us a great opportunity to take a break from operating and enjoy each other’s company. Anita and John, W1SMN organized our public information and outreach activities which were very successful. we had over 30 visitors from the general public during our operation this year.

We all had a great time during Field Day this year and we’re looking forward to doing it again next year.

– Fred (AB1OC)

2014 Amateur Radio Highlights

January 29, 2015 by fkemmerer

2014 Readers Around The World

It is once again time for our annual 2014 Year in Review post. First, I’d like to thank our readers for their continued interest in our Blog. Our blog was viewed about 100,00 times in 2014 from 165 countries around the world. You, our readers have made 2014 our busiest year yet and this provides Anita (AB1QB) and me with great encouragement to continue to provide content for our readers.

2014 was a very busy year in Amateur Radio for us. Our activities included a continued focus on station building, contesting, WRTC 2014, special events, providing presentations to help other in the hobby learn about new things, attending several HAM Events, progress on operating awards, and most importantly – time spent on the air operating.

microHAM Station Master Deluxe Antenna Controller

We upgraded our fixed station to include a microHAM Station Automation system this year. This was a major project that added some nice SO2R capabilities to our Multi-one station as well as automated the sharing of our antennas between our two SO2R Operating positions. More of this project can be found here:

Eggbeater Antennas And Preamps SystemsOn Tower

Eggbeater LEO Satellite Antennas And Preamps Systems On Tower

We also added LEO Satellite capabilities to our station with the addition of some new antennas and electronics on our tower. This allowed us to make our first contacts through LEO birds with linear transponders. Our articles on this project include:

Our Mobile HF Station – Screwdriver Antenna

Our final major station building project was the construction of a state of the art mobile HF station in our Ford F-150 pickup truck. We did this project in phases starting with a simple setup using a 100W radio and HAM Stick antennas through the installation of a Screwdriver Antenna System for the 160m – 10m HF bands and concluding with the installation of an amplifier to enable high power mobile HF operation. You can view the articles on this project here:

AB1OC Operating In the 2014 CQ WPX SSB

Anita (AB1QB) and I continued to be active in several contests this year. We both continued to develop our skills as contesters and our scores and place in the rankings reflected this. You can read more about our contesting activities and what we learned in the following articles:

WRTC 2014 Hollis Site Competitors, Support Team And Referee

We were also fortunate to host one of the WRTC 2014 competition sites. Along with our friend Scott Anderson, NE1RD, Anita and I acted as site managers for the only WRTC 2014 Competition Site in New Hampshire. You can read more about our WRTC 2014 experiences here.

13 Colonies Special Event QSL Card For K2K New Hampshire

Special event operations were a particularly fun part of our on air activities in 2014. We operated as K2K, New Hampshire in the 13 Colonies Special Event, W1AW/1 as part of the ARRL Centennial QSO Party, and as N1FD Celebrating the 35th Anniversary of the Nashua Area Radio Club. It’s great fun to operate in these events and the experience running the pileups that result continued to help Anita and me to develop our operating and contesting skills.

Introduction To The DXLab Suite

We make it a priority to develop a significant amount of our Amateur Radio time to helping others in the hobby learn new things. In addition to writing this Blog, Anita and I try to create and deliver several presentations each year on a variety of topics of interest to the Amateur Radio Community. Our presentation this year included an update of our presentation on Amateur Radio Station Design and Construction and an Introductory Presentation on the DXLab Software Suite. We are always interested in working with Amateur Radio Clubs to deliver the presentation either in person where practice or over the web.

Anita (AB1QB) and I with Bob Heil (K9EID)

We had the fortune to meet some of the legends in Amateur Radio this past year. Anita and I had the opportunity to get meet Bob Heil, K9EID and to appear on his Ham Nation podcast. Bob is an amazing gentlemen and we feel truly fortunate to have the opportunity to get to know him. We also had the opportunity to meet Fred Lloyd, AA7BQ, the President and Founder of QRZ.com. Fred visited our station and did an article about our station on QRZ.com. Anita and I both learned a great deal about HAM Radio and how it came to be what it is today as a result of the time these fine folks spent with us.

Joe Taylor’s WSJT Presentation At the ARRL Centennial Convention

Amateur Radio Conventions and HAM Fests were a major part of our Amateur Radio fun again this year. We were fortunate to attend and speak at the ARRL Centennial Convention in Hartford, CT USA this year – truly a once in a lifetime Amateur Radio experience. We also attended the Dayton Hamvention in 2014 where we had a chance to see all of the latest and greatest in Amateur Radio Equipment.

Our 2014 QSOs By Callsign

We were quite active on the air making almost 26,000 contacts between the two of us. As you can see from the graphic above, about 45% of our contacts were as part of Special Event Operations. We also made a little over 500 contacts from our mobile station, working over 100 DXCC entities in 2014 from the mobile.

Our 2014 QSOs By Band

We were active on all of the HF bands this year. We made our first contacts on the 60m band and I was able to focus on the 6m band and earn a VUCC Operating Award (100 grid squares worked and confirmed) on that band. Anita and I also made our first DX contacts to Europe on 6m in 2014. Anita took quite an interest in the 160m band and she is working on a Worked All States Operating Award on this band. Our operating time using weak signal and satellite modes on the 2m and 70cm bands was limited to a few contacts this year. I did make my first contacts through LEO Satellites in 2014.

Our 2014 QSOs By Mode

We mostly operated in the SSB phone mode in 2014. Anita and I both continue to work on our CW skills and we managed a little over 800 QSOs using CW in 2014. Anita was very active in the RTTY mode as part of her RTTY contesting efforts.

13 Colonies K2K New Hampshire QSL!

All of this operating resulted in quite a bit of QSL activity. We sent a total of almost 4,200 QSL cards in 2014!

We again made a video showing all of our contacts around the world in 2014. As you can see from the video, we were fortunate to work quite a bit of DX in 2014.

Fred’s 6M VUCC Operating Award

All of this operating helped Anita and me to make some progress on operating awards this year. In addition to earning a 6M VUCC, I also completed a Worked All States Award on all 9 HF bands 160m-10m. I was also able to complete several nice regional operating awards (Worked All Europe TOP Plaque, Worked All VK Call Areas and Worked All Africa) as well upgrading my DXCC Challenge Award to the 1,500 Band Country level. Anita completed her JARL JCC Award (she worked 100+ Cities in Japan) as well as her Worked All States Triple Play Award (all states on SSB, CW and Digital via LoTW).

Anita and I had a lot of fun with Amateur Radio in 2014. We are looking forward to another great year of HAM Radio fun in 2015. We hope to share some of what we learn and our experiences with our readers here on our Blog.

– Fred (AB1OC)

LEO Satellite System Part 3 – Final Installation And First Contacts

September 19, 2014 by fkemmerer

Eggbeater Satellite Antennas And Preamp System On Tower

With some help from Matt Strelow, KC1XX of XX Towers, we’ve gotten our LEO Satellite Antennas and Preamp System installed on our tower. We installed the antennas on a sidearm at about 80 ft and installed the preamp system (the upper left gray box) next to the antennas on the tower. The design and construction of our LEO Satellite System was covered in the Part 1 and Part 2 articles here on our blog.

Hardlines At The Tower Base

I choose 7/8″ Heliax Hardline Coax (Andrews AVA5-50) for the feedlines between the antennas on the tower and the shack. I choose this type of cable to hold our losses to end-to-end to about 1.0 dB for the 432 MHz side of the system. Our Icom IC-9100 Transceiver which we will use for satellite work provide 75W of output on the 70cm band which results in a maximum of about 45W at the antenna – plenty of output power for LEO satellite uplink work. The end-to-end loss on the 144 MHz side is about 0.6 dB resulting in 85W out maximum from 100W in. The antennas were connected to the preamps and through to the hardline coax cables using short LMR-400UF coax jumpers and crimp-on N-type connectors were used throughout the system. The conduits that are buried under our lawn had plenty of capacity for the two additional hardline cables (the lower pair of large coax cables in the picture above). I also routed the control cables for the preamps through one of our smaller conduits.

Hardline Terminations At Our Shack

The hard lines (cables with orange and purple tape) were terminated with N-connectors and the shack entry end through grounded PolyPhaser Lightening Protectors.

VHF – UHF Antenna Switching Console

The two sides of the LEO Satellite Antenna and Preamp system were terminated on our VHF – UHF switching console in our shack. The console uses Hofi-Technik Rotary UHF Antenna Switches to allow selection of the LEO Satellite Antennas as well as our M2 Antenna Systems 144 MHz and 432 MHz Yagis and a Diamond X-300NA 2m/70cm ground plane vertical which we use for repeater work.

Preamp Control Cable Terminatons On Tower

Preamp Control Cable Terminations On Tower

We also terminated the control cable from our Preamp System on Control Line Static Suppressors at the base of our tower.

Preamp Sequencers

The Preamp Control Cable was routed to a pair of M2 Antenna Systems S3 Sequencers (top units in the picture above) to enable proper Tx/Rx sequencing to protect the tower mounted Preamps from damage during transmit. These units allow the 144 MHz and 432 MHz Preamps to be turned on/off separately as well as enabling the noise test function on the 144 MHz preamp. With all of the installation work done, I confirmed that the SWR reading on both antennas was in specification at the input to the IC-9100 Transceiver and that the both Preamps work working (via an observed increase in noise level) when they were turned on.

Nova For Windows (FO-29 Satellite Pass)

The final step was to install the Nova For Windows program and download the latest Keplerian Elements for the HAM satellites that are currently operational. Nova For Windows allows me to determine when a given satellite is making a pass that covers both my QTH and the area where I want to try to make contacts. The program can also predict future passes which makes planning satellite operating times easier. The picture above shows the footprint of the FO-29 and the ISS during a pass over my location.

Fuji Oscar FO-29 Satellite

On the day and time that I tried to make my first contacts, only satellites with Linear Transponders were making useful passes overhead. I choose to try my first contact through FO-29 (Fuji Oscar 29) which is a V/U Mode (145 MHz uplink/435 MHz downlink) satellite.

First Satelllite Contact - EA1QS In Spain

First Satellite Contact QSL – Pablo, EA1QS In Spain

With my IC-9100 setup in Satellite/SSB Phone mode to transmit and receive on the proper frequencies and side-bands and with the Tx and Rx sides set to track each other (this is one of the useful satellite Features provided by the IC-9100), I began by locating a clear frequency on FO-29’s transponder and transmitting on the uplink while adjusting my Rx offset until I could hear my own transmissions coming back from the bird. Once I found my receive frequency, I began looking for a station to work. As good luck would have it, I found Pablo, EA1QS in Spain and made my first contact! It took some care to stay on frequency during the brief contact as the doppler shift associated with the path through FO-29 was changing fairly rapidly.

I also made two contacts with W1AW/9, the ARRL Centennial QSO Party Operation in the state of Illinois, USA. I made these two contacts through two different satellites. The first contact was made through VUSat VO-52, a U/V Mode (435 MHz Uplink/145 MHz Downlink) satellite and the second one was made using FO-29 again. I was quite fortunate to make the contact through VO-52 as its batteries failed and the bird went out of service just 12 days after my contact was made.

M2 Antenna Systems 70cm and 2m Yagis On Top Of Our Tower

My early experiences with our new LEO Satellite System have been good. The M2 Antenna Systems Eggbeater Antennas and tower mounted Preamp System work quite well when the Satellites being worked are 30 degrees or more above the horizon. I can use our weak signal 2m and 70cm yagis (top two antennas shown above) and the associated tower mounted Preamp Systems (two grey boxes just below the top of the tower) for Satellite passes that are below 30 degrees. This mode of operation will require computer tracking which I can do via Nova For Windows or the Ham Radio Deluxe Satellite Software both of which I already have. I plan to try this combination in the future and will provide additional setup and operational results for this configuration sometime in the future.

Its been a very busy summer and I have not as much time to operate using LEO Satellites as I would like. With WRTC 2014, the ARRL Centennial Convention over, and the 13 Colonies Special Event and W1AW/1 New Hampshiree portable operations completed, I hope to have more time to devote to Satellite Operation. It’s a lot of fun to make contacts through satellites and this mode of operation will give us the chance to learn some new skills.

World Radiosport Team Championship 2014 Experiences

August 27, 2014 by fkemmerer

Hollis Site Competitors, Referee And Support Team

Anita (AB1QB), Scott (NE1RD) and I had the opportunity to serve as site managers for the WRTC 2014 competition site in Hollis, NH. Our site was one of 65 sites in New England USA (and the only on in the state of New Hampshire). This gave us a chance to be part of the WRTC 2014 event and to meet some of the competitors, referees and the event organizers. WRTC has been called the “Olympics of Amateur Radio” because it brings together the very best Amateur Radio Contesters in the world to see who is the “best of the best”. Here’s a summary of what WRTC is all about from the WRTC 2014 Website:

“The World Radiosport Team Championship (WRTC) is held every four years and consists of 50+ two-person teams of amateur radio operators from around the world competing in a test of operating skill. Unlike most on-the-air competitions, all stations are required to use identical antennas from the same geographic region, eliminating all variables except operating ability.”

Each competitor must qualify based upon results in selected contests over a period of 3 years. There were a total of 63 teams which participated in the event. It is a tremendous achievement just to qualify for WRTC. Each qualifying competitor selects a second person to make up their team. The competitors at our site were Julio Henriquez, AD4Z and Dan Thompson, W4UH. Our referee was Alex Orlov, RW4WR from Russia. We really enjoyed getting to know Julio, Dan and Alex. The stories that they shared and the information and tips they gave us a relatively inexperienced contesters will stick with us forever.

WRTC 2014 Competition Sites

The WRTC 2014 competition was held on July 12-13, 2014 as part of the IARU HF World Championship contest. A great deal of effort was put into selecting and building 65 competition sites for WRTC to ensure that they were as equal in terms of propagation, antennas and configuration as possible. WRTC provided all of the antennas/feedlines, generator power and a tent for each site and each team of competitors supplied their own radios and supporting station equipment.

WRTC Station Kit In Transit

Preparations for WRTC 2014 have been in progress for several years now including planning sessions, station and site tests, team formation and training. All in all, the event is a tremendous planning and logistical effort. Doug Grant, K1DG was the leader and chief evangelist for WRTC 2014. Doug and his team did a tremendous job in making WRTC 2014 happen.

Our part of the WRTC experience began with the pickup of the station kit for the Hollis, NH site on the Wednesday before the event. The station kit consists of a 40 ft Rohn 25G tower, beam/wire antennas, feedlines, generator, tent and miscellaneous equipment.

TX38 Tri-Band Beam Assembly

Ed, K2TE and our “beam team” were at the Hollis, NH site bright and early on Thursday morning to put up the tower and antennas. The heart of the WRTC 2014 antenna system is the TX38 Tri-Band Beam which was designed for WRTC 2014.

TX38 Yagi Installation On Tower

Here’s a picture of the assembled beam and tower ready to be pulled up and into place at our site.

Tower Going Up!

The picture above shows the tower going up. The Falling Derrick System that was developed for WRTC is quite ingenious and it raises the 40 ft tower and beam antenna with very little effort. Each beam team was specially trained in the use of this system to ensure safe setup and takedown of the tower and antennas at each site.

WRTC 2014 Site In Hollis, NH USA

While Ed and the team took care of the tower and antennas, Scott, Anita and I setup the tent, generator, feedlines and “crew tent” at our site. The picture above shows the completed site ready for our competitors.

WRTC Station Radios And Equipment

Julio, Dan and Alex arrived at our site after the site drawing at WRTC headquarters on Friday and proceeded to setup and test their station. As you can see, they brought quite a sophisticated setup! They used Ten-Tec Orion II radios, a microHAM band decoder and antenna switching system and PCs running the N1MM Logger to create a modern, state of the art multi-two contesting station at our site. WRTC competitors used a variety of different radios to compete in the event. You can find a summary of the radios and software used by the competitors here. The Elecraft K3 was the most popular transceiver and a combination of the Wintest and N1MM loggers were used most of the competitors.

WRTC Monitoring System

The WRTC 2014 organizers did some custom design work to facilitate the event. Shown above is the WRTC monitoring system. This system is used by the referee to monitor the power levels of each operator’s radio to ensure that the 100W WRTC power limit is not exceeded. The referees can also monitor the audio from each operator simultaneously and a recording of these audio streams for the entire contest period is also made. All of this is done in the interest of ensuring a fair contest and for judging purposes as needed when the event is complete. A device also monitors the logging streams from the competitors computers to create a live, real-time scoreboard on the web. The scoreboard uses an innovative data collection method developed by Dave Pascoe, KM3T and Bob Raymond, WA1Z to “sniff” the logging information being exchanged by the competitors computers. The data extracted in this way is fed via cellphone data connections to the WRTC headquarters to update the teams scores on the web in real-time during the contest.

The Big Moment – Our Station’s Callsign

On Saturday, just before the competition began, Alex our referee opened the sealed envelope which contained our site’s callsign which was W1T. As with all things about the event, the callsigns were not disclosed to the operators until just before the contest began to ensure that none of the operators specific callsigns were known to others.

Julio (AD4Z) Operating

Once the contest began, our team was all business. Julio is shown above operating CW. He is an amazing operator and can easily operate at 40+ WPM speeds!

Our site was one of the public access sites for the event and we had quite a few visitors from the press and local HAMs who were interested in seeing what WRTC 2014 was about. The event also received quite a bit of media coverage, some of which can be viewed here.

2014 WRTC Medal Winners

An award ceremony was held at WRTC HQ the following Monday to announce and recognize the winners:

Medal winners

Gold K1A 7,184,844 points

Daniel Craig, N6MJ – United States
Chris Hurlbut, KL9A – United States

Silver W1L 6,816,144 points

Rastislav Hrnko, OM3BH – Slovakia
Jozef Lang, OM3GI – Slovakia

Bronze W1P 6,421,383 points

Manfred Wolf DJ5MW – Germany
Stefan von Baltz DL1IAO – Germany

Award winners

Highest SSB (with >35% QSOs on CW)

K1M (IK1HJS/I4UFH) SSB – 2063 CW – 1233

Highest CW (with >35% QSOs on SSB)

N1S (LX2A/YO3JR) CW – 2391 SSB – 1302

Highest Multiplier

K1A (N6MJ/KL9A) 436

Best Accuracy

W1P (DJ5MW/DL1IAO) 1.0% error rate

The final results were very close with only 118,425 points separating the 3rd through 5th place teams. To give you an idea of how close this really was – only 6/10 of a multiplier or about one minute of operating time separated the 3rd and 4th place teams! Some of the operators achieved peak rates of over 300 contacts per hour. This is very impressive considering that Field Day style stations with 100W output were used by the competitors.

WRTC Tower And Antennas At Sunset

Our WRTC 2014 experience was a very memorable one. It was a great combination of amazing people, the best contesters in the world, great application of Amateur Radio technology and some of the best logistics and organization of a large event we’ve ever seen. Truly an Amateur Radio experience of a lifetime!

– Fred (AB1OC)

Our Tower From Space

February 13, 2014 by fkemmerer

Our Tower From Space (Courtesy Google Maps)

I recently had a look at our QTH on Google Maps and noticed that the latest satellite pass had picked up our tower. It is amazing to see the resolution of these satellite photos – our two SteppIR DB36 Yagi Antennas are visible in the photograph.

– Fred (AB1OC)

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Our HAM Station

Notes on the construction and operation of a multi-op Amateur Radio Station

Tag Archives: Tower Construction and Maintenance

An 80m Broadband Matching System

A Portable Satellite Station Part 4 – 2.0 Station First Contacts!

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

Fall Antenna Projects – A New Low-Band Receive Antenna System

Summertime Station and Antenna Projects At AB1OC/AB1QB

2015 Nashua Area Radio Club Field Day Recap

2014 Amateur Radio Highlights

LEO Satellite System Part 3 – Final Installation And First Contacts

World Radiosport Team Championship 2014 Experiences

Medal winners

Award winners

Our Tower From Space