HAM’S LIFE

No! NASA is not looking for hams willing to operate from the planet Mars.  The MARS referred here is the Military Auxiliary Radio System formally known as the Military Affiliate Radio System. 

The program behind MARS started back in November 1925 under the leadership of Captain Thomas C. Rives of the United States Army Signal Corps.  Captain Rives organized a group of amateur radio operators with the intent of utilizing their talents to train soldiers how to use the new technology of radio communications.  He would also use the organization, which was then called Auxiliary Amateur Radio System (AARS), to assist in research and development of radio equipment to be used by the US Army.  AARS members could also provide an instant pool of already trained radio operators for military operations if needed.

That pool of ready trained operators proved very useful when the United States of America was suddenly thrust into war on December 7, 1941.  Many of its members of AARS became military radio operators.  AARS operations along with all amateur radio operations were suspended during the war.  In 1946 AARS was reactivated.

November 1948 AARS changed its name to Military Amateur Radio System (MARS) and was split into two separate groups, the Army MARS, and the newly formed United States Air Force MARS.  (The USAF became a separate branch of the US military on September 18, 1947.  Formally it was known as the Army Air Corp.)

MARS kept its acronym but changed its name to Military Affiliate Radio System on September 2, 1952. The Navy-Marine Corps MARS program was established on August 17, 1962.

The MARS program became well known for its handling of messages and phone patches for military personnel serving overseas.  Modern email and cell phones has almost eliminated the need for MARS to handle personal messages for those serving in the military. 

December 23, 2009 MARS again changed its name while keeping it well known acronym.  The new name for MARS is the Military Auxiliary Radio System.  The Department of Defense give the following definition of a military auxiliary: “an organized body of volunteers prepared to supplement the uniformed services or any designated civilian authorities by provision of specialized autonomous services when called upon or when situations warrant.”  The Civil Air Patrol and the Coast Guard Auxiliary are two examples of Military Auxiliaries. 

With the name change came a modification of its primary mission.  MARS now will provide auxiliary emergency communications for US Military and other federal agencies such as FEMA and Homeland Security.  MARS may now assist state, local, and select private and public agencies with emergency communications. The new focus of the MARS’ mission is homeland security. 

As I have mentioned on this blog several times in the past, while I was in the U. S. Coast Guard, 1962 to 1966, I was a radioman.  CW was still the major means of land/sea communications to ships with radiomen on board.  While serving on the USCGC McLane an incident happened which I believe will illustrate what I am about to say.

We had left Brownsville port and were several miles out in the Gulf of Mexico in route to assist a disabled fishing vessel.  I was the only radioman on board for that trip, I don’t remember why the other two were both missing.  There was a regular schedule for a watch when there is only one radioman on board so he does not have to stand a twenty-four hour watch.

We received a call on 2182 KHz from Port Aransas that they had a Priority message for us.  (In those days 2182 KHz was the AM distress and calling frequency it is now the SSB distress and calling frequency.)  Fortunately they violated CG radio procedure and said it was concerning the death of a family member of one of our crew.  Though I was not on watch at the time I did happen to be on the bridge and heard the call.  Port Aransas had CW capability so I answered the voice communications and direct them to 6383 KHz CW to send message.  This allowed me to be the only one to know the content of the message before it was passed to the captain who was then able to pass it on the crew member whose family member it was about.  It turned out that person was on the bridge when the call came in and he would have most likely the one to receive the message if I had not intercepted it. 

Sometimes when we are assisting with communications in shelters we have people who can hear the radio communications.  Messages are being passed about the well being of family members and this information should be passed directly to the individuals involved privately by those who are running the shelter.  Overhearing a radio communication is not the way for people to learn about the well being of their loved ones nor should they learn because someone else heard such communications and ran to tell them.  Such communications error can sometimes be prevented by using earphones but the message may be being passed to another shelter while a friend or family member of the one being communicated about is in the shelter where another operator is located.  Most operators do now want to sit with earphones on the entire watch just to prevent such a problem not to mention the fact that even with earphones people near by may be able to hear. 

The answer is to take it to the next level of security just as I did on the McLane.  If CW is used for all such communications the possibility of someone hearing and understanding the message is greatly reduced.  It is still a good idea if possible to use earphones when copping such a message. 

If a more complex communication system is possible digital communications can increase the level of message protection even higher then CW but a CW station is much easier to set up and use if there are enough CW proficient operators available.  Where VHF or UHF FM is being used sending such a message can be as easy as using a Code Practice Oscillator and send the message with the PTT button depressed.

As a radio operator in the United States Coast Guard it became my lot to serve on the USCGC McLane out of Brownsville, Texas. The McLane was 125 feet long and 25 feet wide and operated on HF frequencies from 2 MHz to 32 MHz with 180 watts of CW power. While serving on the McLane we went as far south as the Yucatan Peninsula. During the time when we were underway we needed to maintain communications with the Coast Guard Radio New Orleans NMG which at times was close to 1500 miles away. This was very successfully done with one antenna called an H antenna.

The H consisted of a single wire running from a 10 foot support pole on the starboard stern corner running up to a few feet from the starboard side of the yard arm across by the mast to the other side of the yard arm and down to a 10 foot support pole on the stern port corner of the ship. There were two wires with insulators running from the yard arm to support the wire on each side to support the antenna away from the yard arm and mast. The wire was tapped with another wire at the .36 of the total length of the antenna point which was near the starboard support wire from the mast. That wire was the feed line and it was run to an insolated feed through which came inside the radio room. The HF transmitter was attached to the insolated feed through.

Carefully studying the antenna I realized if the wires were removed from the two stern supports and stretched out straight it would form an off center fed Windom antenna. The off center fed Windom can be feed with 600 ohm ladder line, 300 ohm twin lead, or just a single random length wire as was the antenna on the McLane. The antenna on the McLane was not quite ½ wave long for our lowest frequency of 2686 KHz (called KC then) but it still worked quite well at that frequency. The transmatch or antenna tuner was apparently able to compensate for the difference.

The Windom was a common antenna in the 1930’s but it is not selective against spurious radiation. With the advance of Television sets which lead to TVI problems the Windom fell into disuse by the middle 1950’s. While underway the McLane had no problem with TVI so the antenna worked very well. (If 50 ohm coax is used at the transmitter output to a low pass filter then coax is run between the filter and the transmatch TVI problems are no worse with the Windom then with a center fed dipole.)

The antenna requires a very good RF ground. This will not only improve the operation of the antenna system but it will also help prevent stray RF inside the shack while transmitting. One reason the antenna may have worked so well on the McLane was the ocean is the ultimate ground.

The antenna is a half wave dipole, that is half wave at the lowest frequency used, fed at the 300 ? point (.34 of total length on one side and .66 of the total length from the other end.) with a single conductor or twin lead.

A Windom antenna is said to work on the fundamental frequency and the even harmonics so the 1.8 MHz antenna would work on 3.6 MHz, 7.2 MHz, 10.8 MHz, 14.4 MHz, 18 MHz, 21.6 MHz, 25.2 MHz, and 28.8 MHz. This would make it on or close to the 160, 80, 40, 30, 20, 17, 15, 12 and 10 meter bands. On this type of antenna the antenna tuner acts as a real antenna tuner, unlike that of a coax fed antenna, and can make up for the difference. The frequencies used by the McLane were not as close to the even harmonics of the lowest frequency used as the ham band frequencies are to 160 Meter.

Most modern HF transmitters have linear amplifiers for use with SSB. Linear amplifiers have a very low spurious output so if a low pass filter is used between the antenna tuner and the transmitter output there should be very little problem. Also most TV’s are now used on cable or dish which are not as susceptible to TVI as they were in the earlier day’s television sets which were attached to antennas on the roof of the house.

Many hams feel constrained when it comes to putting up antenna because of limited room but as described above a very effective antenna was used by the United States Coast Guard on the very limited space of a 125’ ship. If you can put two poles on the roof of your house which are parallel to the back fence and run a single 260 feet long wire starting at your back yard fence up to one pole then over to the other pole and then down to the back fence again you should be able to put up an antenna which could be used on any desired frequency from 1.8 MHz to 30MHz.

Test question T8A09 of the technician class amateur radio license asks, “What is an appropriate way to initiate an emergency call on amateur radio?” This is a good question but as a former radio operator for the United States Coast Guard and one who has tried to keep current on distress operations I do not completely agree with the answer.

The answer in the test pool to question T8A09 is,” Say ‘Mayday, Mayday, Mayday’ followed by ‘any station come in please’ and identify your station”. No matter what my opinion is this is the answer that must be marked on the test to be considered correct.

The word “Mayday” repeated three times means “I am in distress and anyone who can assist please answer.” So the phrase “any station come in please” is not necessary. There is a format.

The distress message starts with the word “Mayday” repeated three times and then the station call repeated three times. If this is all any one receives of the distress call it is sufficient to bring response. Knowing the station call sign means the person to whom that call sign is assigned can be found and with some investigation may lead to finding that person, hopefully in time.

Next, without weighting for an answer, the most important information in the message is sent. That would be the location. If nothing else is known but the location it means assistance can be sent to that location. They may not know what the nature of the distress is but just knowing there is a distress will result in a unit being dispatched to assist.

It is important that assistance know what the nature of the distress is so proper equipment can be dispatched. While that information can be obtained if communications can be established with the station in distress while assistance is underway or if no communications is possible it can be ascertained upon arrival but that could delay assistance and time is at an essence.

The number of people involved, a description of the vessel, vehicle, or craft involved, and the nature of any injuries that may have been incurred will also be good information.

Then the station in distress waits for a response. The reason the full message is sent before a response is received is because it is possible that someone who is not able to communicate the station in distress may hear the call and summon assistance.

Just remember when answering the questions on the test there is not way to challenge the answers. The most correct answer is the right answer and,” Say ‘Mayday, Mayday, Mayday’ followed by ‘any station come in please’ and identify your station” is the most correct answer.

The Coast Guard Cutter McLane had two transmitters on board for CW operations. The transmitter for 500 KHz was a TDE a big black box, max DC input power 125 watts, frequency range 300 KHz to 18 MHz, and had a VFO. We also had an AN/FRT23 for HF operation but it was crystal controlled. So the only transmitter that would allow ham radio operations was the TDE but I had been given direct orders from the XO not to use any of the ship’s transmitters for amateur radio purposes.

About 9 months after reporting aboard the McLane I was married and then about a year after that my oldest daughter was born. My wife was at that time WN5NEP and her doctor was W5MSQ.

The local ham radio club had a SSB net every Sunday afternoon on 80 Meters. One Sunday while I was on duty (that means staying aboard to protect the cutter while it is in port) I wanted to check into the net but using the TDE on CW was my only option. Even though I was on CW the net welcomed me in and after the net was over Doc (W5MSQ) and I shifted down to the CW portion of the band and had a lengthy QSO.

During our QSO the OD (officer of the day), a boatswain’s mate who knew nothing about radios, stopped by the radio room when he saw there was some activity. He asked me what I was doing.

I knew I was had. Violation of a direct order from the XO was sure to bring serious consequences. I may have gotten by with it if I told him I was testing out the transmitter but that would be a lie.

I looked up at him and simply said, “I am talking to my wife’s doctor.”

At that he started laughing so hard he could hardly contain himself. He walked off the bridge laughing and repeating, “I am talking to my wife’s doctor.”

He didn’t believe me, he didn’t tell anyone, and I didn’t get into trouble. That was the first and last time I used the ship’s transmitter for amateur radio use.

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See information on the McLane at http://www.silversides.org/mclane.html