Virginia and several of the ladies joined us at the transmitter site for devotions this morning, then they cleaned the entrance, hallway, kitchen, lunchroom and restrooms.

Virginia and I worked at cleaning the tall narrow window next to the new transmitter.  It had to be the dirtiest window in the building with large blobs of concrete stuck to the glass.  (I never realized how well concrete can adhere to glass!)  It also had paint over-spray on both sides.  This window is not perfectly clean now, but looks a whole lot better than it was!

Virginia cleaning inside of window located between the new transmitter’s disconnect switch (left) and transformer (right)

I decided to check the voltage on the air handler contactor coil.  The initial voltage was 21 volts with no discernible drop as it was energized and pulled in.  Although the output of the 24vac transformer is lower (due to 105vac input instead of 120vac), there was minimal voltage drop in the output winding, compared to the 8vac drop in the smaller transformer removed yesterday.

The transmitter was operated this morning at 440 kw with normal program on the north and south patterns with no problem.  Later, Dave and I again took field strength measurements at the airport (about 2.5 miles northeast of the transmitter site), while Jonas and Daryl operated the transmitter.  We have been informed that the self (TWR)-imposed maximum should be 1 volt/meter.  We determined that 225 kw would need to be the limit on power in the Caribbean (omni) pattern to meet this requirement.  No governmental limits are known, although when 500kw into a 5/8 wavelength tower was being used, during the first years of operation by TWR Bonaire, the field must have been close to 2 volts/meter at this same airport.  As mentioned earlier, the north (Cuba) pattern and the south pattern, even at 440 kw have much lower field strengths towards the airport.  The main beam of the north pattern, which passes to the west of the airport, is directed toward Cuba.

There was one arc (as detected by an arc detector) in tower 3’s tuning unit last night while using the Caribbean pattern.  This afternoon, Daryl and I went to that tuning unit to observe where the arc might be occurring.  By operating the transmitter at 250kw with heavy modulation, we were able to see the exact location of the arc.  The arc originated from the grounded end of an insulator to a wide ground strap on the floor.   How can you get an arc over an inch long from one grounded point to another ground that are already tied together with a short ground strap?  I cannot explain it (yet), but some unexplainable, strange things do happen with transmitter powers of this magnitude.  We tried to improve the ground connection and will see whether an arc is detected tonight.  [When an arc is detected, the detector shuts down the transmitter for a fraction of a second which extinguishes the arc.  This only happened once last night.]

We left the site just after 5pm this evening and, unless something unanticipated happens, we don’t plan to return until Monday morning.  Hopefully tomorrow (Saturday) will be a relaxing day.  Virginia purchased tickets for us to take an unusual excursion tomorrow at noon.  Stay tuned for tomorrow’s blog!

On Sunday, lots of people start arriving for the dedication.  Planned activities start with a lunch buffet at noon Sunday and continue until a ‘BBQ at the beach’ on Thursday evening.  Pray for unity and stamina as the small TWR Bonaire staff (including us) are involved in so many ways and that God’s grace might shine through us.