Wednesday, January 6, 2016

Dahlak Island Adventure-9F3USA/P1

      In 1972-73 while assigned to Kagnew Station in Asmara,  Ethiopia ( now Eritrea) I had some great opportunities for SWL and Ham DX.  As part of the radio club there, I had the opportunity to operate the club station ET3USA.  The club had a block of callsigns assigned to it that allowed a limited number of hams to operate under the license off post, using the callsigns ET3USB-ET3USF.  This was in the early 1970's. Some of that activity will be the subject of future columns.
       Early in the Spring of 1973 I was approached by Mike Durbin, WA5TKC, with an invitation to join him and KP4CKX who also worked at facilities in Asmara in what he termed a " mini-field day" operation he had planned. Turned out, it was what amounted to a short DX-pedition to an island in the Red Sea.
       The plan was to go in late May to one of the islands in the Dahlak Archipeligo off the Ethiopian Coast near the port of Massawa.  Mike worked the details out with the local government authorities, which was no mean feat given the political situation at the time.  There was rebel activity in Eritrea at the time and any use of radios out in the field might have been suspect.
       All the hurdles appeared to have been cleared and early on a Friday morning, a group of us caravanned down the 72-hundred foot mountain to Massawa to catch our ride to the island.  That drive was always an adventure in itself, being on a two lane paved road that would not exactly be considered a highway. It was a 110 kilometer drive containing 27 switchback turns.
       In addition to the three of us who would operate the radios, a group of a half dozen others were going along to go fishing.  That helped spread out the cost of chartering the boat and also would cut down on the provisions we would have to take. The operation was going to basically be a long weekend,  and would be nothing like the heavily financed trips taken by groups these days.  I think we figured the total cost of the trip, including gas to drive up and down the mountain was about $300 US!
       All of the equipment taken fit inside one small footlocker.  The radios were two Heathkit HW-101's, tube type rigs that ran about 100 watts out. There were two rolls of wire, some nylon rope, mikes and keys and paper for logging. ( No computers!!!). There was a 1 kw gasoline powered generator. Outside the footlocker, we carried three Jerry cans for fuels, a couple cans of oil and the antenna, which was a 14AVQ trap vertical that covered 40-10 meters. There were also a half dozen or so short poles that would make up a short mast.
       The plans were to operate one station at a time on 40-10 and to string an 80 meter wire for communication back to Asmara.  Our ride out to the island would be on a 40 foot Arab fishing dhow powered by sail and small inboard engine. It would be about a four hour trip from the harbor to our destination. This would not be a luxury trip. Seating was flat on the open deck.  Any cooking on board would be in a small sand pit on the forward deck!
       The first problem came after all the gear was loaded on the boat in the harbor.  Government officials came by and wanted to inspect everything again.  They wanted to do so out of our sight, so we went to a nearby restaurant and had an unscheduled early lunch break, followed by ice cream ( which for me turned out to not be a good thing later!!)
       About two hours later, we were finally able to leave the harbor. Water was smooth in the harbor, but not so much when we got out in the open water. Seas were a little rough, and for awhile it was great fun to stand in the bow of the boat and have the spray hit me in the face. About an hour later, the trouble came when I went back amidships to sit down on the deck. Then the effects of the spicy meal and ice cream hit along with the first signs of queasiness.  Someone told me not to look at the horizon, but to look only at the deck to stall off the seasickness. I tried that, but the movement of shadows from the rigging moving back and forth on the deck finally did me in!  I had no sea legs!
       It was a miserable couple more hours until we reached the smoother waters near the coast of the island. I was still a bit queasy as we made our approach, but all that ended when a minor disaster struck. The small boat ran aground!  The boat's operator did not seem too concerned, saying we should just unload there.
       We all went over the side and found the water to be about neck deep.  It was time to lower the equipment over the side and carefully carry it over our heads to shore. Somehow we got everything ashore with nothing getting wet, not even the logging paper!
       It was then that we got our first look at our operating situation.  There was a small shelter made of driftwood already in place that provided a little shade. There were higher dunes about 100 feet back from the water line.
       The first order of business was to get the generator started and checked out. It was set up a hundred feet from the shelter to keep the noise down a little. The whole expedition almost became just a fishing trip at that point as the generator simply refused to start.  Murphy's Law was in full force.  The generator that had started many times on the first pull back up on the mountain was being cantankerous at sea level.

       Mike and one of the fishermen did some kind of magic that also appeared to be some kicking, then playing with the carburetor that finally got it going.  I am guessing that perhaps some adjustment on the engine to make it operate in the thin air on the mountain top might have been the problem.
      The next step was to get the antenna put up.  That ended up being about a fifteen minute operation...just stacking the tubing for the vertical together, driving some stakes into the sand, standing it up and guying it off.  Unfortunately, I have no pictures of the antenna, but there are some pictures of the antenna and the boat in either the July or August 1973 QST magazine DX column.
The vertical was set up right at the water's edge with radials running off into the water.  We did not have enough coax by just a few feet to have the antenna out in the water itself at low tide.
       It was now time to set up the gear.  The operating tables were two portable tables that we set up under small shelter, running the coax out to the vertical and firing up.  An end fed wire was strung from the shelter up to the small mast that we put on top of the nearest sand dune. It would be for our 80 meter link back to Asmara about 120 miles away. We tuned up one of the HW-101's into the wire first.  There was no antenna tuner, one of the advantages of old school tube type radios.  The Heath radios had a pretty wide range pi-network output circuit and we did not even worry about the match. The plate current dipped and loaded and that was that! Communications was established with ET3USF and our safety line was secured.
       The other HW-101 was loaded up into the vertical.  It appeared to load up easily,  without too many dips and loading adjustments. We were set to go, almost on our planned schedule.  We had put out the word via the ARRL that we would be on the air by 1600 GMT.  The delay at the harbor and the increased time to unload along with the problem with the generator had pushed us right up to that time with nothing to spare.  Our local time was GMT plus three, so it was 1900 our time. 
        I really don't remember if we had announced a frequency on which to look for us or not,  but we found a clear spot below 14300 as I recall and put out a CQ, signing the callsign for the expedition,
9F3USA/P1  (" Nine Fox Three Uniform Sierra Alpha Stroke Papa One" a real mouthful!)  I don't know what we expected from that one short three-by-three call. Maybe we thought the world would fall in on us right away,  so it was a disappointment when there was silence. It was the same after three such calls.  Then Mike made a rather lengthy CQ call and unkeyed. After a short silence, a tentative call came back: I8HH.  I remember that call well being the first that we worked.  The exchange was a little longer than the usual expedition contact being the first and the fact that there was no crowd.  I remember he repeated our call a few times, perhaps thinking it would attract attention to us.  It did.
       When Mike cleared the contact, there were three stations calling.  He worked those quickly, and then the roof fell in. The pileup was on.  We worked a string of Europeans, then one JA who said he was going to announce our presence on a two meter repeater there in Tokyo.  Things got really heavy after that with several pages of JA's worked in quick succession!

       The pictures are a little faded with age, but here you see WA5TKC ( on the right) and myself (WA5IEX) on the left.  The covers were off the '101's ( and us!).  There was no concern about RFI or TVI out there and the temperature on the beach was about 130 degrees F.

       There were no computers on this trip!  All logging was by hand,  with one operating, and the other logging most of the time.  When one person alone was operating, it was quite a juggling act. Note the "small paperweight" used to hold down the log sheets in the sea breeze!
       Most of the operating was on twenty meters during the day.  Forty meter operation at night was tough because we had no way to operate split and had to stay below 7100 because that was the top of the band for us. Than meant no US contacts on 40 meters,  which left a lot of folks unhappy.  A few did call us on CW on our operating frequency which was fine with us, but that apparently did not occur to many.  While we had taken a key with us to operate CW, the QSO rate was so great on phone that we never got around to that.  There was some fifteen meter operation Saturday afternoon.
       Twenty meters was open well into the night with hundreds of US stations worked.  At one point the crowd got a bit boisterous and as we tried to work by call areas, folks were calling out of turn and it was getting impossible to pick out callsigns. At one point we got some great help from Bill, W2ONV who could hear us very well at his Saddlebrook, New Jersey QTH to try to calm the pile down a bit.  The fact that we were running only 100 watts to a vertical made things a bit more difficult because the roaring hoard could not hear us under the thunder of the pileup when we tried to answer someone.  It was incredible!
       The next day, about mid afternoon, something happened that I will never forget.  We were working mostly African and Asian stations on 20 meters and in quick succession worked HS4, XW8 and A2C stations, then a few YU's. Callsigns were in the log that most of us would have lusted after at our home QTH's.  A few minutes later the XW8 called again to say we were still very strong there and that " it must be nice to have an exotic callsign like that"!  Whoa!!!
       That Saturday and Sunday morning were a blur.  Again, compared to the big DX-peditions of today it was really small potatoes but it was a real trip for us. Sunday was packout day for the return trip. Because of security concerns and our military curfews for being on the road, we had to be back on the mountaintop before dark Sunday.  Travel on roads outside the city after dark was prohibited.
       The trip back up the mountain was something.  It was hard to believe that it had come and gone.  The biggest thought was how we would ever top this later in our ham careers. This fear was pretty much allayed the very next time we were on the air from the club station and the pileup on the ET3 callsign was still heavy by anyone's standards.
       The one disappointing thing was that the trip did not count as a separate country.  The IOTA or Islands on the Air program was either in its infancy or not begun at the time. But still, it was quite something to hear and HS4 and XW8 calling us at the same time!
       There had been no major problems after the early problem with getting the generator started. Oil consumption was a little high and we went through our spare cans, but the boat captain leant us enough to keep the generator going through Sunday morning.  We ran out of beer Saturday about midday.  But the fresh fish cooked on the beach over driftwood was fabulous.  And if it got too hot behind the radios it was just a quick run across " hot sand, hot sand " for a dip in the Red Sea to cool off.  What more could you ask for??
       But if there were fears that this little experience would leave us jaded to any "ordinary"activity in the future have proven groundless. There is still the same thrill of working a new one today, the adrenalin still pumps during the CQWW DX Test and there is still the same thrill at hearing a JA on 80 or 160 meters as the first time.
       If nothing else, the experience gives some appreciation for those who go on the truly difficult trips, spending thousands of dollars to put some rare spot on the air.  The thought that what they are doing is many multiples of what we went through that time brings that about.  It also brings some appreciation for what folks on the other end of the pileups go through.

Sunday, January 3, 2016

The Loop Project

       I have mentioned the use of loops in the past under the heading " Loop the Loop".  This past week in one of my Facebook Groups there was a question about Low Frequency Reception and the use of loops.  I posted a picture of a loop my father and I built and since there was considerable interest in the group I thought I would put the information here.
       This loop was build back in 1990 and has seen considerable use.  It is a box loop or some would call a solenoid loop that is three feet across and tuned with a three gang variable capacitor. It tunes form roughly 180 to 1500 kHz.  By tapping the coil and selecting one, two or three gangs of the capacitor, the tuning range can be varied.
       A tuned loop is actually a very simple device,  with the difficulties being not in the electrical design but in the mechanics.  This loop was made of wood and designed to be rotated in azimuth and tilted in elevation.
       To keep the loop from tilting over,  my father who worked with me on the project,  made the base from a salvaged solid core door.  Now it must be mentioned that this loop is not small and is not light.  The base must be heavy to make sure the loop is stable and will not fall over or try to move when its turned or tilted.
       The basic idea of any tuned loop is that it consists of a parallel tuned circuit.  The loop is actually the coil part of an L-C circuit. It resonates at the frequency for which it is being used.  A variable capacitor connected across the winding takes care of that chore. The one thing that is important if deep and clean nulls are to be obtained is that all connections should be very short.  For that reason, we chose to mount the variable capacitor right in the center of the loop itself. This is not a remotely tuned device ( one must  often chose between convenience and performance!!) It should be noted that no other connection is made to this parallel tuned circuit.  It stands completely alone.
       The connection to the receiver is made through a two turn link wound a couple inches away from the main winding and connected to a short piece of coaxial cable that then runs to the receiver.      A simple loop could be made simply by winding wire around a cardboard box or a plastic trash can and connecting the capacitor across the main winding and the link winding to the receiver.  I have used similar arrangements many times,  but this project came about with a desire to have something permanent and nice looking.
This is the loop sitting on a table in the back yard of my home.  The cross arms are three feet in length, with wooden plates on the ends that support the windings.  Additional wood pieces around the edges prevent the tension of the wire windings from puling the loop out of shape.  This was a feature that was added after that problem showed up and resulted in an almost complete redesign of the antenna!

       This view shows the mounting of the variable capacitor in the center of the loop. An alligator clip allows connection to one, two or three gangs of the capacitor as needed to change the tuning range.

This view shows the windings...In this case there are thirteen turns on the loop.  They are spaced about a quarter inch apart.  The two turn link is to the right.
Another view of the loop in my back yard looking toward the house and showing the tuning capacitor.
Another view of the loop with my forty foot vertical in the background.  This loop is a little large for permanent use in the house at my location, so I generally use it when operating out in the yard at this table or portable at other locations.  I have used it with a Radio Shack DX-440, My Icom R-75, Hallicrafters SX-96 and my MacKay low frequency radio.  I do not seem to need a preamp with it.  I have used it portable at Galveston and at various locations in the Texas Hill Country, usually just trying to find an electrically quiet spot. It has brought in NDB's from all over the United States and Canada, several from Cuba,  ZBB from Bimini, many from Mexico and Central America and even some from South America,  best NDB DX being from Ecuador.  I have also received broadcast stations from Europe and Morocco while visiting at Galveston.  I have found that the ability to null interfering stations to allow many stations otherwise unloggable being captured. It also helps in nulling noise. The lobes are much broader than the nulls, which are very sharp and deep,  I can totally eliminate local broadcast stations with it. Tilting the loop in the elevation plane can also allow reception of stations at different distances in the same azimuth direction. Tuning of the loop is very sharp, especially on the lower frequencies.