Dodged a Bullet

With the eye of Typhoon Vongfong passing north of Guam by ~40 miles, many people on the island felt that they had dodged a bullet. Top winds ranged from 40mph in the area around KTWR to 70mph at the northern end of Guam. Had the storm hit us directly, we would probably have lost our commercial power and water supplies.

Vongfong is now a super typhoon headed for southern Japan. Please pray for the people in its path.

KTWR could generate power with any of its three generators, but there was no back-up water supply. Since it is too muddy to work in the antenna field, we took the opportunity to install a 500gal water system. Now that it is functional, it is much easier for us to operate during the frequent water outages that occur during rainy season.

Making Power

Installation of KTWR's 30KW solar power system has been completed. It turned out to be a tough thing to do during rainy season. It is also not so easy to get full power output during the monsoon that we had just experienced. However, this photo shows the inverter pumping over 22KW into the power lines at the station. That is ~3 times the power that we consume at home when a water heater and two air conditioners are running.

We are already in the planning stages of expanding this system with an additional 37.5-67.5KW system. That would be plenty of power to make our power meter "spin backwards" during the day. This will cause KTWR to accumulate credits that can be used to reduce the power costs of our nightly broadcasts. Reduced costs will expand our ministry opportunities.

Matrix Now in Use

 

We had a very busy day today (September 19th). This was the day we had to move connections for two antennas  and one transmitter to the antenna switch matrix. We were a bit concerned when the day started off with thunderstorms, but the weather turned out to be good for most of the day.

Once we cut the antenna feedlines apart, we were committed to getting the job done. As can be seen from the photos, most of our staff worked on this day-long task. Antennas 2A and 2B are connected at one corner of the matrix.  TX7 is connected to the opposite corner.

 
 

TX7 tuned to the new connection very well. It should work better than it did with the temporary switch connections in our old dump truck.

When it Pays to Cut Corners

The antenna switch matrix was tested for its ability to maintain the proper impedance with various transmitter-to-antenna connection combinations. The transmitters ideally want to see 300 Ohms with no reactance as the RF power travels from the transmitter to the antenna. That perfect situation almost never happens, so the transmitter must tune to make up for mismatches. Our matrix is unique in that there are cases in which it allows multiple switch paths between particular transmitters and antennas. Each path must appear the same to the transmitter to avoid extra time spent in tuning.


Maintaining the proper distance between conductors helped the matrix exhibit the 300 Ohm resistive load. That was not particularly difficult. Keeping the reactive load as close to 0 as possible was more challenging. Quite a bit of work went into using 45-degree fittings to avoid 90-degree corners. Sharp corners add inductance. Too much inductance can cause problems in transmitter tuning.


The good news is that the measurements were nearly perfect for all switch combinations at all frequencies in the 6-18MHz range. Avoiding the sharp corners in the pipes really paid off. The transmitters will essentially not notice when the matrix is connected between the antennas and the transmitters.

We are currently working on verifying that the automated switch control will work. Once this is proven to work, TX7 and ANT2A/B will be connected to the matrix. Other transmitters and antennas will follow during the next several weeks.

Little House on the Prairie

After a lot of hard work and dry weather, we managed to construct a little block building to house the antenna switch controller and the power panel.  The forklift definitely made the bucket brigade for pouring the roof concrete much easier.

While the concrete was setting, a trench was dug between the transmitter building and this block house.  Conduit and power wiring has been installed and the trench has been refilled.  Conduit and its associated power and control wiring has also been installed between the block house and the ten antenna switches.

The switch controller and the power panel have been mounted inside the block house, but are not yet fully connected to other equipment.  We should be able to do some testing of the switches next week, unless something unexpected comes up.  (Something unexpected nearly always changes our plans.)  

Panels are Up

The installation contractor has made good progress with the solar power array at KTWR.  All 120 panels have been installed. One interesting side benefit that had not occurred to us before is that the panels make a nice shaded area for picnics or just relaxing. The installers took advantage of that fact because the sun has been brutal for the past several days.

The contractor will work on the inverter and wiring this week.  We hope to have this system providing power by the end of the month.

Steel Henge

We seem to have gotten into the habit of erecting things that resemble ancient astronomical tools.  This photo shows that good progress has been made with our 30KW solar power array.  The most difficult part of the entire project was to get the posts aligned and set in concrete.  With that milestone passed, installation of the arms and rails that hold the solar panels has been going quickly.  It is expected that at least some of the panels will be installed tomorrow.

After the panel installation, what remains is installing the inverter and the wiring.  Once this is done, we hope to save quite a bit of money on our power bills.

Playing in the Mud

Since this is rainy season on Guam, digging in the dirt is actually a messy process.  That is what we faced when trenching for the power and control lines for the antenna switch matrix.  The conduit that houses these lines will go from the transmitter building to the concrete block structure shown in the distance to the right in this photograph.  The controller that manages the switches and the power panel will be housed in that structure.

Once the power and control lines are connected to the equipment in the block building, there is still quite a bit of connection work to be done.  Each switch must be connected via conduits to the block building.  After that is done, we can test the controller and the switches.  The matrix tuning process will be the next step.  That will be done to improve the performance of the transmitters and the antennas.

Digital Audio “Liberation”

July and August have been busy months for the Guam IT/IS team.

In July Alain Paradis (representing Martin IT Solutions and Netia Corp.) joined the Guam IT/IS team (Doug and David Gregson, Grant Hodgins) on Guam for a week of training and configuring our new Digital audio playout equipment for TWR's Guam and Sri Lanka broadcast stations.

Alain Paradis, Doug Gregson, David Gregson (Planning Session)

Grant Hodgins, Alain Paradis, Doug Gregson

It is appropriate that the week for performing the work was during Guam’s Liberation celebrations. 

Guam celebrates “Liberation” during the month of July remembering how the island was liberated by the Allied forces from the Axis forces (Japanese) during World War 2.  This event is normally themed with “freedom” and marked with memorial services, a carnival, and an all day parade ending with fireworks.

In an analogous way, TWR Asia’s radio broadcast outlets (Guam and Sri Lanka) are being liberated from using old software and hardware for content management and delivery.

Although the old equipment was very reliable – it has reached the end of its life for service and support.  The new system will free Asia to expand its connectivity and provide better quality control and reporting while running on a software which is tightly integrated into TWR's IT/IS Business model.

The upgraded Netia Radio Assist software will be fed by TWR’s media asset management system (LDMS) and will be the last component of a system that will deliver Bible based programing by radio to a large part of Asia. 

Guam has been using very reliable and well supported NETIA Content delivery software since 2000 when the station switched from Analog recordings to digital.

Please pray for us as we carry out testing and configuring of these vital systems.

The Project is scheduled to be completed by December 2014.

The Not-So-Tangled Web

Now that most of the RF "plumbing" work between the switches is complete, the guys have switched to working like Spiderman.  While the copper tubing was better for curved runs, the cables work better for straight runs.  The copper is reminiscent of queue railing at a theme park.  The cables somewhat resemble a spider web.  Even with all of the weather disturbances passing by Guam lately, the weather has worked out well for making good progress on the antenna switch matrix.  The sun has been brutal, so frequent breaks are needed to avoid dehydration or heat stroke.  Please pray for safety, strength, and wisdom as work continues on this system.

Plumbing Work

Now that the antenna switch matrix switches are in position, work has begun to connect them to each other. Instead of using wires, 1-1/2" copper tubing is used for the RF interconnections. It will take hundreds of feet of tubing and several days of work to form all of the connections between the ten switches. It is a good thing that all three of the guys shown in the photo have plenty of plumbing experience.

Old Friends Leaving KTWR

TX1 and TX2 were the first transmitters installed at KTWR.  They were put on the air in 1977.  They each have over 120,000 hours of broadcast time on them.  Lately, we had been using them as back-ups for the other three transmitters at the station.  It was determined that it was time to sell them.  A radio ministry in the States now owns them.  They have been disassembled, packed, and containerized for the trip overseas.

It definitely looks, sounds, and feels different in the transmitter hall now.  We hope that demand for Christian radio programming will increase to the point that we will need a fourth transmitter in the future.  We have a nice empty place in the room to put it.

Solar Power Coming to KTWR

Several months ago, KTWR started the process of getting a solar power system installed at the station.  It took us quite a while to get the 30KW system designed.  Now that the parts have been packed for shipment, we are getting more excited about having this operating at KTWR.  As you can imagine, our power bills are a large chunk of our yearly budget.  Having a 30KW grid-tie system will save money that can be used to expand TWR's ministry to the Asia/Pacific Region.  We expect the system to be operational in July.  If this system works as expected, we intend to add more power generation capacity.  We are allowed up to 100KW for a grid-tie alternative energy capability.  There will be times of the day during which the power meter will run backwards.  That will be fun to watch!

Heavy Metal

We are now back to focusing on the antenna switch matrix. After servicing the backhoe, we were able to install two of the three feedline hangers on the pad. These hangers hold the feedlines taut while taking the stress off of the switch connection points. Each hanger weighs ~1000lbs and they are quite awkward to move. Both the forklift and the backhoe were needed to get them into position.

There is one more hanger remaining to fabricate and install.  It will be small enough that we can do the final positioning without the heavy equipment.  Once that is done, we can attach some feedlines to the hangers and build the shelter for the switch control system and the power distribution panel.  

Regular Japanese DRM Broadcast

 

After years of working on getting ready for DRM, it has not quite sunken in that we are now doing regular DRM broadcasts to Japan.  These Sunday broadcasts at 12120KHz at 1057-1156UTC are being eagerly received across the country.  Many listeners use software defined radios (SDRs) to tune us in.  These radios are hardware combined with software running on a PC or a laptop.  Many listeners have sent us proof of reception with screenshots similar to the one shown above.  The narrow peaks are normal analog broadcasts.  The wide "Bart-head" is the DRM signal from KTWR.  Not only does that signal carry audio, but it also has text info such as the station ID and a short message that scrolls across the receiver display.

 

Most of the early listeners to this broadcast have been shortwave radio enthusiasts.  Japan seems to have more SW hobbyists per capita than any other country on the planet.  They were actually the ones who encouraged us to start these broadcasts.  Most hobbyists will tune in a broadcast they have not heard before once or twice for short times to get a QSL card or other souvenir from the station.  However, we have been greatly encouraged by the fact that these listeners listen to the entire program.  They tell us how much they enjoyed hearing the programs for their content, not just the signal quality.

 

We do pray that this experiment expands to more days and more countries in the near future.  This technology allows people to clearly hear the gospel while using 1/3 the power of analog broadcasts.  The power savings allows us to expand the ministry to more people groups.

ANT2A is Up

After a little over a week since it fell, ANT2A is back up in the air and coonected to TX7. We are very grateful for the volunteers who worked hard with us to get the job done. The Lord also gave us some good weather for antenna work.  The antenna worked well last night and the transmitter tuned easily to the new hardware.

One difficult part of the repair was in the slew switch. (It looks a bit like a lunar lander in the photos.) When the antenna fell, it bent some components in the switch that were made out of large copper pipe fittings. The riggers were able to make new parts which worked out well.

Now that this work is complete, we can consentrate on building the antenna switch matrix.  The control software work has progressed very well.

Major Detour

For the past several weeks, we had been working hard on the antenna switch matrix.  It would have been really helpful if we had that already in operation.  We were hoping to have part of the matrix operational in early May, so that we could increase the power for a TX7 broadcast.

Last week, ANT2A had one of its cable swage clamps fail.  This caused one end to fall to the ground.  This sort of thing tends to break many insulators and cables.  We had to use jumpers to connect TX7 to ANT3 and reconnect TX2 to ANT2B.  This allowed us to continue our normal broadcast schedule.  Without the matrix, we also had to do our Japanese DRM broadcast on TX6 and ANT1 instead of TX7 and ANT2A. 



 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The antenna has been reassembled and is now back up in the air.  We are still working on repairing the slew switch and its input transformer.  The slew switch is what controls the direction that the radio waves go when they leave the antenna on their way to the listeners.  The transformer is the set of wires needed to adapt the signal from the transmitter to the antenna system.

 

Once repairs are complete, we can resume work on the matrix hardware.  In the meantime, we do have a short-term visitor who is working on the control software.  We should have a usable software system by the end of the week. 

 



Progress

There have been various points of work these last couple weeks.

1) Fabrication and placement of Matrix complex. The 'feed line beam' (or hanger) has been constructed. This is a massive 40 foot beam that Jim has welded together.  This will be the beam where the feed lines from the building will come to and then be distributed to the matrix.

2) The PLC has been fabricated and tested with an antenna switcher. The micro switches and relays have been added. It was great to see a switching test - it took only 8 seconds for the switch to change from A to B. The seven switchers have been fit and are now on the pad.  There are three more switchers that will need the frames fabricated and then readied for the matrix. 

 

3) In preparation for the coming frequency period antenna two has to be fitted for transmitter seven.  This is pre-switcher matrix broadcasting.  Because of the amount of programming we are putting on TX 7 we need to use antenna two and the old A/B switch.  By the end of April the antenna matrix first stage will take the place of the A/B switch and switching between antenna two and three.

And on March 30, 2014 as the new season begins KTWR will be broadcasting it's first DRM broadcast - in Japanese.

Moving Right Along...

It's great to be able to show things coming together.

Paul has completed substantial work on the retaining wall of the pad.

We have seven switchers now that have been mounted to the stands.

The switch control box has been connected and we've been able to test the switch and establish a switching time. (There are still a couple microswitches to be installed and wiring to be completed.)

Four of the mounted switchers have been moved to the pad. Now we can show a good picture of the matrix coming together. 

Stay tuned...

Boxed In

The final delivery of the antenna switchers arrived at the site today. They were all crated and boxed up quite effectively by the HCJB team in Elkhart. There was no damage at all to the cargo.

Work continues with the switcher stands and mounting the switchers. We now have a good assembly line as switchers are mounted on the stands.  

Jim is even boxed in as he completes the rest of the stands.

Hmmmmm... do you have an idea of an upcoming project?