HAM’S LIFE

The rapid developing electronics field has a very close association with ham radio and I refer to other technologies to illustrate that the expediential advance in technology covers much more then just electronics.  It may be a stretch in the mind of some to link this with ham radio but in my thinking there is a connection.  

Saturday night I heard the last part of a radio talk show that apparently had a guest earlier in the show.  The guest, it would seem as I followed the call in discussion, believed that modern electronic technology came as result of a UFO crash in Roswell, New Mexico in July of 1947.  Now I can not prove nor disprove if a UFO crashed in Roswell or if any technology was learned from that craft if it did crash but I do not believe we need UFO conspiracy theories to understand modern technology advancements.

The Industrial Revolution is considered to have started around 1760.  Up to that time things did not change much.  When people wanted to go somewhere by land they walked, rode a beast of burden, or rode in some kind of wagon or cart drawn by such animals.  If they wanted to go by water they had to row or be wind driven.   Harnessed steam power change that.

The world started changing.  The change, sense that time, has continued to change at an accelerated rate.  Swifter means of transportation and greater productivity of factories prompted the need for faster and more efficient communications.

The word telegraph comes from Greek and means distant writing.  Though a few telegraph devices using electricity were developed prior to Samuel Morse’s telegraph but they died while Mr. Morse’s telegraph took root and grew.  The telegraph started the age of electronic communications in 1837. 

Just 40 years after Mr. Morse showed the world how to put messages on wire and send them long distances in a flash Alexander Graham Bell showed the world how to put the human voice on wire and send it over long distances. 

While the world of electronic communication was growing during 1800’s and early 1900’s other fields of technology also grew.  Accelerated development was happening in all fields Firearms, Electric lights, Internal Combustion engines, photography, and the list could go on. 

Nikola Tesla demonstrated a wireless telegraph in St. Louis, MO in 1893 but Guglielmo (Italian for William) Marconi made it to the patent office first with an economical and effective system that communicated more then just a few meters away.  It was 60 years (1837 to 1897) from when the first effective wire telegraph was patented until the first effective wireless telegraph was patented and it was 40 years from when the telegraph was invented until the telephone was invented but it was only 2 years from when the wireless telegraph was demonstrated until the wireless telephone was demonstrated.  1899 A. Fredrick Collins successfully made a voice transmission.

In 1906 Lee De Forest placed a grid in the vacuum diode and made it a triode he called an Audion.  The Audion had a little gain but it was not until about 1912   triodes with sufficient gain make an oscillator was able to be produced.  The vacuum tube was further developed.  It had more grids added and it was reduced in size.  Using the vacuum tube allowed transmitters to operate with a continuous wave (CW) on a specified frequency rather then the parasitic signal spread over a band.  Receivers could then use active devices rather then the passive units of prior days.    The little glowing marvel made it so that almost every home in the United States had at least one radio receiver in it by 1930.

In 1939 RCA released the AC/DC radio using the All American Five vacuum tubes and radios started appearing in several rooms in the home.  They could fit in packages small enough to sit on a book shelf, kitchen counter, or bed side night stand.  Soon many companies started selling these efficient, attractive, small, inexpensive, and very dangerous radios.  Compact battery operated vacuum tube radios were also being produced.  Automobiles with radios started showing up just after 1930.

By 1947 Television antennas were sprouting on the roofs of houses all across the United States. 

In 1925 Julius Edgar Liliendfield filed the first patent for a transistor in Canada.  The new transistor was very similar in operation to a Field Effect Transistor.  Because Mr. Liliendfield did not publish any research and his patent did not cite any examples of the device being constructed Oskar Heil was able to patent a similar device in 1934.

Though Bell Laboratories was not able to patent a working bipolar transistor prior to December of 1947 they had been working on the concept of a solid state replacement for the vacuum tube for several years before 1947.

Now all of this was prior to the events that happened in Roswell in July of 1947.

Looking at the technological developments that took place from the beginning of the Industrial Revelation until 1947 and noticing the accelerating advances in that technology and comparing it to the rate of acceleration sense 1947 personally I would say we are just about on target where we should be without the need of some extra-terrestrials technology input.     

It is not often you hear a song written about ham radio but here is one that I found recently that I thought the readers of this blog might enjoy.  You will find it on www.youtube.com.  After going to youtube just enter the words CQ Serenade in the search or go directly to:

http://www.youtube.com/watch?v=1MgOyWW5uG8&feature=PlayList&p=94C98DA34ACD5BAC&playnext=1&playnext_from=PL&index=2   and enjoy the music and photos. 

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.

Ramsey Electronics has several inexpensive easy to assemble electronic kits. Some are specifically amateur radio related and others are not. The QAMP40, QAMP30, and QAMP20 are 40,30 and 20 meter 20 watt linear amplifier. Being linear it will run CW, SSB, or AM. It can be driven with ½ to 2 watts with a power requirement of 12 VDC at 4 Amps.

The amplifiers have about a 10 DB gain so 1 watt in equals 10 watts out and 2 watts in equals 20 watts out. They were designed to be used with the Ramsey QRP transmitters which run at about 1 watt.
The instruction booklet, as with all their kits I have assembled so far, is very well done and can be followed by anyone even with no electronic knowledge.

Ramsey’s estimated assembly time is 4 hours for beginner, 2 hours for intermediate, and 1.5 hours for advanced builders. I did not time myself but I would say that their timing estimate is fairly accurate.

The instruction booklet, as with all their kits I have assembled so far, is very well done and can be followed by anyone even with no electronic knowledge.

Alignment is very easy. Basically it is just a matter of setting the bias by adjusting a small potentiometer.

The work horses of the amplifier are two P16NF06 MOSFET transistors. They are run in Push-Pull format so as to reduce potential second harmonic output. It has a 3 stage pi network low pass filter output to further reduce the harmonic output. The input and output to the transistor are both through ferrite wideband transformers.

transformers.

The exciter input uses a T-R relay circuit which is operated by a simple diode detector to sense when RF is applied and a two transistors amplifier circuit to drive the relay. If the power switch is not on the relay will not actuate and thus the exciter can be run “bare foot” but when the power is on it will switch on as soon as the exciter is keyed.

When testing the QAMP I found that ½ watts in gave 5 watts out and 1 watt in gave 10 watts output. An IFR service monitor’s power meter was used for the test. The efficiency is about 30 to 35% which is about where a class AB amplifier should run.

The kits require winding three toroid coils and two ferrite bead transformers. They use enamel insulated wire which Ramsey says can be tined to prepare for soldering without removing the insulation. About a year ago I purchased some of these kits and they surprised me because I was able to tin them using Ramsey’s process but recently I purchased a few more and found the insulation would not burn off. Thus scraping off insulation before soldering was necessary before I was able to solder them. I suspect they may have changed supplier of this wire.

Another problem I have is they supply the MOSFET transistors in plastic envelopes that do not appear to be ESD (Electrostatic Discharge) protection packages. They also do not recommend ESD caution be taken during construction which makes me wonder how many of these transistors are destroyed by electrostatic discharge by builders who are not aware of the danger.

Over all, considering the cost, they are very great little amplifiers to boost the power of your QRP rig.

Almost a year ago I wrote an article on one of my other blogs which prompted a comment with a question. The question follows: “one question i have is
are the following principals basically the same - how do they differ? Heterodyne Regenerative and Super Regenerative.

That article was posted on this blog site on 02/01/2008 titled “The Regenerative Receiver.” I want to try to answer that question here because I must have left something ambiguous in that article.

The word “heterodyne” is derived from two Greek words; “hetro” which means different and “dyne” meaning power. By combining the two words we see that it latterly means a different power. A heterodyne is a signal which is produced by mixing two or more signals in a non linear device or to say it another way heterodyning is the process of mixing two or more signal frequencies to produce a different frequency signal. When two frequencies are mixed they actually produce two new frequencies. So if a 7.100 MHz signal was mixed with another signal having a frequency of 6.645 MHz it would produce an output of 455 KHz and another of 13.745 (the sum and the difference of the two frequencies). In that case, considering 455 KHz is a very common IF frequency, the 455 KHz signal would probably be the one desired and the 13.745 MHz signal would be filtered out.

The technique of heterodyning was developed by a Canadian inventor and engineer named Reginald Fessenden.

After the process of heterodyning was developed and understood the superhetrodyne receiver could be developed. Prior to the superhetrodyne receiver and after amplification was possible receivers had a series of RF amplifiers ahead of the detector. Each of these amplifiers had to be retuned when the receiver frequency was changed. The superhetrodyne receiver eliminated the need to have a series of RF amplifiers that had to be tuned separately. Normally there is one RF amplifier ahead of the mixer though there can be more and sometimes the mixer is the first stage. The input to the mixer is tuned and the frequency of the local oscillator which produces the signal to be mixed with the incoming frequency can be variable (in some cases the local oscillator is crystal controlled) so the output frequency always remains the same. Each RF amplifier, which is actually called Intermediate Frequency (IF) amplifier, can be tuned to the same frequency no matter what the input frequency is. Using an IF frequency allows the construction of more selective circuits. Fixed frequency filters can be easily added to the IF giving greater selectivity then possible with LC circuits.

Ease of tuning, improved gain, and increased selectivity are three advantages of the Superhetrodyne receiver. An other advantage was provided by the fixed If frequency being fed into the detector is it allows the signal of the IF to be mixed with the signal produced by the beat frequency oscillator (BFO) which makes receiving CW and SSB much easier (the BFO heterodynes the IF frequency down to audio frequencies).

Regeneration is a process where by some of the output signal of an amplifier is sent back, in phase, to the input. When the output of an amplifier is sent back to the input it is called feedback. When a sufficient amount of the output signal is sent back to the input in phase the amplifier will sustain its own signal producing process called oscillation. Feed back can be regenerative (positive feedback or in phase feedback) and degenerative (negative feedback or out of phase feedback).

As the article I mentioned above describes, the regenerative receiver used a small amount of positive feedback to improve the receivers amplification and its selectivity so one tube acting as the RF amplifier and detector worked very efficiently. When the feedback was increased to the point where it started to oscillate a signal was being produced which would mix with the incoming signal to produce a tone so a CW signal could be read.

A super-regenerative receiver is a regenerative receiver which uses a quenching frequency to prevent oscillation.

So I guess the answer to the question I was asked is heterodyne and regeneration are two different processes and regenerative and super-regenerative differ in that the latter uses a quenching frequency.

From 1896 when Guglielmo Marconi invented the wireless telegraph until 1901 when he added a tuned circuit to the receiver the radio receiver was just an antenna connected to a wire which went to a detector. After Marconi added a tuned circuit the receiver had a little selectivity. It was not until 1906 when Lee de Forest added the grid to the diode and the receiver was able to have something more then just passive devices. With the grid RF amplifiers could be added before the detector and audio amplifiers after the detector which was a great improvement.

The tuned radio frequency (TRF) radio became the receiver of choice. The problem was that each stage had to be tuned separately and the tubes had to have low amplification or they would oscillate. The TRF remained the only way to add amplifiers ahead of the detector until Edwin Armstrong conceived the idea of superhetrodyne during WW1.

In 1914 Edwin Armstrong, an amateur radio operator, patented the regenerative detector. This was a real break through in radio receiver progress.

The regenerative receiver uses a positive feedback which greatly improves both the sensitivity and the selectivity. In the earlier days the receiver had, compared to today’s receivers, a very large coil for the input tuned circuit which fed the grid. It had a coil of just a few loops of the wire in the plate circuit. The coil in the plate circuit, called a tickler coil, would be physically moved in the proximity of the input tuned circuit until the positive feedback was almost enough to cause oscillation when receiving an AM station and it was adjusted just into oscillation to receive a code station. The oscillation would produce a heterodyne, two signals mixed in a nonlinear circuit which result in an output of the sum and the difference of the two input frequencies, which could be heard as a tone this allowed true CW to be used. Up to then only MCW could be used.

The gain of a regenerative receiver using just one tube can be up to about 20,000 and if a MOSFET, not developed until many years later, is used a gain of 100,000 is possible.

Then in 1922 Mr. Armstrong patented the Super-Regenerative receiver. The super-regenerative detector uses a “quenching” frequency usually about 20 KHz to 30 KHz though other frequencies are also used. Using the quenching frequency to quench or stop the detector’s oscillation there is no need to adjust the tickler coil. This makes the receiver easier to operate and increases the sensitivity. Because they are inexpensive and easy to make these receivers are still being built and used, mostly in VHF and UHF ranges, today. (Note: Super-regenerative receivers do not work on 5 KHz deviation FM it just sounds like a carrier being received.)

One of the biggest disadvantage of the regenerative and the super-regenerative receivers is they radiate a lot of noise over a wide area of the frequency on which they are being used. Back in the Sixties Heath Kit had a little 10, 6, and 2 meter transmitter receiver kit called the Tenner, Sixer, and Twoer. These units used a super-regenerative receiver. In 1965 I had a twoer installed as a mobile. That was the year the United States Coast Guard transferred me from Brownsville, TX to Coast Guard Radio Station New Orleans (NMG). My wife and I were driving around Metery (just across the river from New Orleans) looking for a place to live. We had our infant daughter with us. The Metery Police at that time were using 150 MHz radios. As we were driving I saw a police car sitting on the side of the road. I was very careful to obey all laws as I passed him. I came to a full stop at the stop sign. And when I pulled out from the stop sign he followed me and shortly on came the blue lights (I had never seen blue lights before but I guessed they meant the same as the red ones) so I pulled over. He stopped right behind me and one officer got out of one side of the car and the other from the other. They approached the car with hands on their guns, though they were still holstered, and one grabbed my door with his free hand and the other grabbed my wife’s door. The questions started flying, who was I, why was I there, and finally what is that radio. It took years before I understood why they pulled me over. My Twoer opened up their squelch when I passed by and again when they came up behind me and they wanted to know why.

Just as a little added note. Erwin Armstrong invented the FM transmitter and receiver a few years after the super-regenerative receiver.

With the advent of email the @ sign has gained popularity. It is now as well recognized as the & sign.

The “American Morse”, also known as “Railroad Morse”, had a character for & which has been used by amateur radio operators most of whom did not know they were using an “American Morse” character. Because the modern amateur radio operator uses “International Morse” which has a different timing arrangement then “American Morse” the letters e and s are used to make up the & sign. So when es is sent it is recognized as “and” but it really is the & sign.

(The original character makeup for & was not es but a dit with a slightly less time then that used between letters followed by dididit.)

Because the @ is used in email addresses and there was no code character for @ email addresses were difficult to exchange via CW. This problem was addressed by the ITU-R.

On May 24, 1844 the first transmission of a message by telegraph to be publicly observed was sent so it was on this date 160 years later (2004) the Radio Communication Bureau of the International Telecommunications Union (ITU-R) formally added the @ (which they called “commercial at” or “commat” for short) to its list of Morse characters. The new character is AC (Underscore means it is not two characters but all sent together as one) so it is sent as didadadidadit (• — — • — •).

The ITU-R is the same group that required amateur radio operators to demonstrate an ability to send and receive “International Morse” until they dropped that requirement on an international level in 2003. Think about it!

The @ sign is the first new character to be officially added to the Morse character set sense World War I. The information on what that character added during WWI was or its exact date of its addition seems to have been lost.

The problem now is to get the sign into common use so when sent other hams will be able to understand. We need to spread the word to others and use the character on the air.

History of the @ sign:

The origin of the @ sign has been lost to antiquity but it was known to be used by scribes to shorten the Latin word “ad” (at, to, or toward) as early as the 6th or 7th centuries.

The symbol can be found on 14th and 15th century clay pottery which were used to hold grain or wine and seems to have some connection to the measure or quantity it contained. Later it came to mean “at the price of”. Underwood added it to the 1885 typewriter keyboard.

The use of use of @ as part of the email address is credited to computer engineer Ray Tomlinson who in 1971 used it to separate the name of the intended recipient from their location with a character that would not appear in either name.

Saturday night HAARP concluded the transmissions for the phase of the operation I have been speaking about in this blog. 6.7925 MHz was noisy at my location Saturday night and I was unable to hear the reflected signals but the 7.4075 MHz much quieter and I was able to hear about 80% of all the returns.

Thank you to Alexey for finding my error (see comments on previous post). I can’t believe I did what I did. Maybe the fact that I had not been able to sleep more then 3 to 4 hours for the past several nights had some effect. What ever the reason was I knew something was wrong but I went over and over and still could not see it. I checked several sites for the distance between the earth and the moon and they all said the same thing but it just did not seem the distance was right. They said 385,000 KM to 405,000 KM which means the round trip is 770,000 KM to 810,000 KM. Alexey wrote all the zeros out so I saw where I was going wrong. 405,000 Kilo Meters is 405 Mega Meters thus 405,000,000 Meters. RF travels at 300,000,000 Meters a second. I should have calculated it as 810,000,000/300,000,000 or 810/300 which equals 2.7 thus it takes 2.7 seconds for the signal to reach the moon and return. That would seem consistent with what I heard.

One interesting thing I heard Saturday night on 6.7925 MHz (at least interesting to me) was a CW message being sent. A station could be heard establishing communications with another station just a few hundred hertz above the HAARP transmission. I was trying to hear the reflection so I did not pay any more attention to it then to the fact that it was there but while the one station was sending its message I diverted my attention to what was being sent and found it was a string of five letter groups. Having been a military radio operator in the 1960’s this was a familiar pattern. It was an encrypted message format used by the US military. The interesting part of this was to see that someone is still using CW to communicate messages of importance. CW is alive and well.

It was a very interesting and educational experience for me and I hope if HAARP conducts any future experiments of this nature, and I am sure they will, they will again invite the hams to participate. For this privilege I thank HAARP.

HAARP made their transmissions on 6.7925 MHz last night (if you are not sure what I am referring to see yesterday’s post). From my location the echoes were heard but they faded in and out. There were a few times when they were surprisingly strong. The skywave was a solid S7 copy and constant.

The distance to the Moon is between 385,000 KM and 405,000 KM thus a round trip distance of 770,000 KM and 810,000 KM. Considering the speed of radio wave travel is 300 Million Meters per Second it would seem the round trip should be far less then one second (.810/300=.0027 Distance/speed=time). Considering that the transmissions were 2 seconds long and then a 3 second wait it would seem that the beginning of the reflected signal should arrive back in about .0027 seconds and the end .0027 seconds after the end of the transmission. The transmission was a solid 2 second tone with no data. What I heard was the skywave tone for 2 second in a little less then a second after the skywave signal ended the reflection came in with very little gap after it ended before the skywave signal started again. Can someone explain why the delay length?

The signals will be transmitted again tonight at 0630 to 0730z on 6.7925 MHz and 7.4075 MHz at 0730 to 0830z.

January 18-19, 2008 The HF Active Auroral Research Program (HAARP) will be attempting to bounce signals near the 40 meter band signal off the Moon.  This project is in association with the Long Wavelength Array (LWA) but Amateur Radio operators have been invited to assist.  

HAARP is a joint effort of the United States Air Force, United States Navy, and the University of Alaska Defense Advanced Research Project Agency.  Its purpose is to “understand, simulate and control ionospheric processes that might alter the performance of communication and surveillance systems.”.  The facility is located near Gakona, Alaska.  

The LWA is a collective effort of the South West Consortium to advance astronomy by probing the depths of space using frequencies between 10 MHz and 88 MHz.  It is located at the University of New Mexico in Albuquerque, New Mexico.

The transmissions will begin January 19 at 0500z (that is 118 8:00 PM Alaska Standard Time) on 6.7925 MHz and will continue until 0600z.  On January 20 6.7925 MHz will again be used from 0630 to 0730z and then 7.4075 MHz will be used for the transmissions from 0730 to 0830z (frequency occupancy at the time transmissions are to be made may make it necessary to adjust the transmit frequency slightly).

A standard communications receiver with a simple 40 meter dipole antenna is believed to be sufficient equipment to receive the lunar echoes.  The transmission format will be in five second cycles starting exactly on the hour 1/19 and half hour 1/20.  The HAARPS transmitter will send a signal for two seconds then listen for 3 seconds for the lunar echo then the cycle will be repeated.  These transmissions will be in CW only.  

It may be possible to hear the original signal as well as the bounced signal so an accurate time piece should be part of the observer’s equipment.  That is to say listen to WWV close to the time of transmission and set your watch to the exact second.  This way any signal heard during the first two seconds of the sequence will be the original but any signal heard before the next sequence start will be a lunar reflection.  

HAARP investigators would like to receive signal reports from amateur radio operators who listen whether or not they are able to receive the lunar echo, the transmitted skywave or both (or neither).

If you would be interested in participating send your reports by e-mail to mbreport@haarp.com .  Include your call sign, description of your receiving equipment and antenna, and your location.