HF Antennas In A Restricted Space

Experiments can be expensive

I want to share my experience with those of you who have recently passed their test and are looking for that perfect HF antenna that will suite their “New Shack” at their home location. My thoughts were focused on an antenna that would cover as many of the Ham bands as possible, that could be hidden on my apartment patio deck. I did, as most of you will, a lot of reading on the subject and eventually chose a Current Loop Antenna that was the rave in the UK and it set me back about $350 with shipping and tax. I set it up on my patio and I started to tune through the Ham bands and hardly heard a thing, I mean that, apart from static and a couple of stations, one in Alaska talking to a fellow in California, I heard nothing. I was beginning to think that there was something wrong with my Radio, a brand new Icom 7100 and John VA7XB very kindly invited me to his home and we attached my radio to his antenna. The radio immediately jumped to life with more stations than I could count. I tried several CQ calls and was rewarded with a reply from South Carolina some 2600 miles away, on 70 watts. What a thrill that was. Now knowing that my radio was in perfect shape, I again started to search for the perfect antenna.

Having proved that my radio was fine, I took the current loop antenna apart and put it where the proverbial squirrel stores his winter supplies and started looking for another antenna. I found an antenna called “The Tarheel Antenna” this is a motorized Multi band antenna with excellent ratings, it is a mobile Antenna that I could mount to my patio railing and also mount it on my vehicle for away from home outings. Well, although I could hear more stations compared to the Current loop, they were so far below the noise level that they were not useful at all. Having spent another $700 plus on the Tarheel I still did not have a working antenna. All of the successful Hams will tell you that your success is based on Antenna, Antenna, Antenna.

I have reached the conclusion that my location is in a null zone created by the apartment blocks in which I live. The HF Spectrum is a fickle thing sent to try us. Imagine, if you will, a letter L reversed, the bottom leg runs North South and the vertical leg runs East West, the vertical leg being south of the bottom leg. I live on the East side of the bottom leg on the second floor, rite in the corner created by the bottom leg and the vertical leg. My location is protected by both of the apartment blocks.

My mistake was trying to buy the antenna that would cover the most HAM bands as possible, right up front, before checking to see if there were any signals at all. My advise to you and the whole reason for this small article, is to choose an antenna that covers one band, lets say the 20 meter band. Try to buy the cheapest antenna you can find, within reason, try to stay away from the Chinese antennas, they are usually of very poor quality. Put up the antenna at night if you are like me and live in an apartment, if you live in a house you will have a lot more room to play with than apartment dwellers. If you can hear contacts that are well above the noise level, have fun and start to build your log book. If like me, you hear little or nothing, you have just saved yourself a ton of money. Buying antennas can be very expensive as I have found to my sorrow.

I have not, however given up. There are lots of opportunities as a mobile station with my Tarheel antenna and setting up, as in the Field Day event, in a park with a long wire antenna. In my opinion, the whole idea of being a HAM is to have as much fun as possible with what you have and I certainly intend to do so.

~ Robert VA7FMR

Robert found his solution sometime later, see https://ve7sar.blogspot.com/2019/11/the-novemberdecember-communicator.html - Ed

Our Antenna Workshop

An opportunity to practice what we preach

We’re now between Basic courses and we constantly tune-up our methods, learning from feedback. Like other licensing courses, we cover the Introduction to Amateur Radio, Ohms Law, basic components, propagation, transmission lines, antennas and block diagrams of receivers and transmitters. The big section toward the end is Rules and regulations. It’s big because it typically counts for 25 to 30% of the exam questions and we leave it so students have enough material to relate those rules to the technical part of the course. 

On a Saturday after the transmission lines and antennas have been covered, around Week 4, we host the class at an antenna building workshop. It is one of those sessions that is hands-on and sets aside our course from the many others that are offered. In this session the students build a dual band roll-up J-pole antenna that they cut, solder and tune, then take home as their first antenna. It is a fun session and brings home many of the points that are discussed in the classroom sessions and offers many their first exposure to solder smoke.

All course attendees receive a complimentary membership to SARC for the current year, and hopefully we will end up with some new permanent members and hams who will embrace our hobby.

Re-instated in the course is an extra week. We have been teaching for 7 weeks with the exam on the 8th. We will now add a week after the formal teaching but before the exam. That will give the students an extra week to study and allow us to add a week to include the 'how to get started' session that we trialed at our January 2020 general meeting. It was a success, see https://ve7sar.blogspot.com/2020/01/get-on-air.html

Back To Basics: F2 Region 'Hops'

What is the maximum distance along the Earth's surface that is normally covered in one hop using the F2 region?

B007-003-002

A. 2000 km (1250 miles) 
B. 300 km (190 miles) 
C. 4000 km (2500 miles)
D. None, the F2 region does not support radio-wave propagation

There are at least a dozen questions in the Canadian Basic Question Bank that touch on propagation, this is just one of them. The science of RF propagation can take volumes to explain, let’s see if we can summarize the basics.

Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering.
Radio propagation is affected by the daily changes of water vapor in the troposp
here and ionization in the upper atmosphere influenced by the Sun. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for Amateur Radio contacts, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.

Several different types of propagation are used in practical radio transmission systems. Line-of-sight propagation means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna. It does not necessarily require a cleared sight path; at lower frequencies radio waves can pass through building walls and foliage. Line of sight transmission is used in short to medium range radio transmission such as garage door openers, cell phones, cordless phones, walkie-talkies, wireless networks, FM radio and television broadcasting and radar, and satellite communication, such as satellite television. Line-of-sight transmission on the surface of the Earth is limited to the distance to the visual horizon, about 40 miles. It is the only propagation method possible at microwave frequencies and above. At microwave frequencies moisture in the atmosphere (rain fade) can degrade transmission.

At lower frequencies in the MF, LF, and VLF bands, due to diffraction radio waves, can bend over obstacles like hills, and travel beyond the horizon as surface waves which follow the contour of the Earth. These are called ground waves. AM broadcasting stations use ground waves to cover their listening areas. As the frequency gets lower the attenuation with distance decreases, so very low frequency (VLF) and extremely low frequency (ELF) ground waves can be used to communicate worldwide. VLF and ELF waves can penetrate significant distances through water and earth, and these frequencies are used for mine communication and military communication with submerged submarines.
At medium wave and shortwave frequencies (MF and HF bands) radio waves can reflect or refract from a layer of charged particles (ions) high in the atmosphere, called the ionosphere. So radio waves transmitted at an angle into the sky can be reflected back to Earth beyond the horizon, at great distances, even transcontinental distances. This is called skywave or "skip" propagation. It is used by amateur radio operators to talk to other countries, for diplomatic communications, and by international shortwave broadcasting stations. Skywave communication is variable, dependent on conditions in the upper atmosphere, and can be disrupted by events like solar flares, it is most reliable at night and in the winter. Due to its changing nature, since the advent of communication satellites in the 1960s many long range communication needs that previously used skywaves now use satellites.

Solar activity has a cycle of approximately 11 years. During this period, sunspot activity rises to a peak and gradually falls again to a low level. 

An international panel of scientists co-chaired by NOAA and NASA release reports every few months on the state of the sunspot cycle. This is probably the most accurate source in terms of what is likely to happen.

Current Sunspot Cycle 24 gave a smoothed sunspot number maximum of about 69 in the late Summer of 2013. The smoothed sunspot number reached 68.9 in August 2013, the official maximum. Now, at the start of 2020 we should be at or near the bottom and it is hoped things will start to improve. We are currently seven years into Cycle 24. The current predicted and observed size makes this the smallest sunspot cycle since Cycle 14 which had a maximum of 64.2 in February of 1906.

Back in April of 2019, the previous report predicted that the  solar minimum would likely happen between July 2019 and September 2020. In the most recent report dated December 2019, they are predicting that the minimum has been pushed back. They predict that it will now occur sometime between November 2019 and October 2020.

As for the upcoming Solar Cycle 25, they are still predicting that it will be similar in intensity to the last solar cycle with a smoothed sunspot number (SSN) of 115. The peak is predicted to occur between November 2024 and March 2026.

When sunspot activity increases, the reflecting capabilities of the F1 layer surrounding earth enable high frequency short-wave communications. The highest-reflecting layer, the F2 layer, which is approximately 200 miles (320 km) above earth, receives ultraviolet radiation from the sun, causing ionization of the gases within this layer. During the daytime when sunspot activity is at a maximum, the F2 layer can become intensely ionized due to radiation from the sun. When solar activity is sufficiently high, the MUF (Maximum Usable Frequency) rises, hence the ionization density is sufficient to reflect signals well into the 30 – 50 MHz VHF spectrum. Since the MUF progressively increases, F2 reception on lower frequencies can support potential low band amateur radio paths. A rising MUF will initially affect the 27 MHz CB band, and the amateur 28 MHz 10 meter band before reaching 45-55 MHz TV and the 6 Meter amateur band. The F2 MUF generally increases at a slower rate compared to the Es MUF.

Since the height of the F2 layer is some 200 miles (320 km), it follows that single-hop F2 signals will be received at thousands rather than hundreds of miles. A single-hop F2 signal will usually be around 2,000 miles (3,200 km) minimum. A maximum F2 single-hop can reach up to approximately 2,500 miles (4,000 km). Multi-hop F2 propagation has enabled low-band VHF reception to over 11,000 miles (17,700 km).

The correct answer to our question "What is the maximum distance along the Earth's surface that is normally covered in one hop using the F2 region?" therefore is (C) 4,000 Km (2,500 miles) 

~ John VE7TI

Early SARC History

SURREY AMATEUR RADIO

(1975-1981)

The Surrey Amateur Radio Club had its beginning in the Electronics Lab of the North Surrey Senior Secondary School in the spring of 1975. In a discussion with electronic students who had recently been successful in obtaining their Amateur Radio Licenses, the idea of a local radio club was put forth. Cory Balbraith, VE7CGR, liked the idea so much; he spread the word far and wide via the airwaves. It was so well received that plans for a fall start gathered momentum.

The electronics instructor, Doug Moore, VE7CBM, was granted permission by the administration to hold meetings in the electronics room on Tuesday nights. Incidentally, the club held their meetings and theory classes on Tuesday s for the first two years before switching to Monday nights.

The initial meeting was held on the first Tuesday in October 1975. Many members of today were present at that meeting. As Doug, VE7CBM, had to the key to the school, he was quickly elected President, with Cary Miller, VE7CFC, as Vice President and Cory, VE7CGR, as Secretary-Treasurer. The duties of the President were threefold; open up the school, chair the meetings and make sure there was coffee and cookies available.

In January, Cory graduated and went to Nanaimo to work for radio station CHU. Fred Orsetti, VE7CJG, was elected to take over the duties of Secretary-Treasurer.

The theory lessons began in December with Bob Searle, VE7CHB, Cary, VE7CFC, Fred, VE7CJG and Doug, VE7CBM, all helping out. Over the years, several members gave their time and energy to teaching the theory Garreth Gammon, VE7CGG, Lee Middleton, VE7BHS, to name a couple. Mike Holly, VE7AVM, was instrumental in making tapes and teaching CW for several of the beginning years.

The club had access to the school's Kenwood 510 but was never able to make use of it for various reasons.

Our windup to a very successful first year was the Field Day held at Fred's QTH in June 1976 and supervised by Mike, VE7AVM. For the majority of members, this was a first. We didn't do all that well but enjoyed the outing and fellowship. Those involved were Mike, VE7AVM, Cary, VE7CFC, Carl, VE7CLC, Mike Heritage, VE7CLE, Ed Dunham, VE7CIO, Laurence Holloway, VE7ADC, Jerry Szakal, VE7COI, Ralph Webb, VE7BVG, Vic Medway, VE7CON, Pat Cavanagh, VE7CAV, Bob VE7CHB, Doug, VE7CBM, Peter Desrosier, VE7CGZ and his wife Lise.

S.A.R.C

1976 - 1977

President ------- Fred Orsetti, VE7CJG
Vice Pres. -------- Bob Searle, VE7CHB
Sec. Treas. ---- Carl Bertholm, VE7CLC

We acquired a portable tower and TA 33 Jr. beam for use on Field Day. We moved to Monkey Mountain, just east of Abbotsford on the suggestion of Al Neufeld, VE7CDC. The site will always be remembered for its wonderful view and the terrible access road. Bob, VE7CHB, and Peter, VE7CGZ kept the crew furnished with nourishment throughout the weekend.

The club was licensed as VE7SAR under the sponsorship of Cary, VE7CFC, holder of an advance amateur certificate.

Our first annual Christmas Party was held at the Islanders on the King George Highway near White Rock.

This was also the year of the Canadian Pacific Airlines (CPA) tour conducted by Tony Craig, VE7XQ.

1977 - 1978

President ------- Mike Holley, VE7AVM
Vice Pres ----- Carl Bertholm, VE7CLC
Sec. Treas ---- Mike Heritage, VE7CLE

The Ten Meter net was initiated with Fred, VE7CJG and later operated mainly by Carl, VE7CLC and Mike, VE7CLE. In the early days, we did have code practice by Mike, VE7AVM after the net. The net is held every Sunday on 28.675 MHz at 0400 Zulu.

The second annual Christmas party was held at the Surrey Inn where we competed with the QRM of the Saturday night disco.

Field Day was a great success. The club station was again located high on Monkey Mountain. It was announced in QST that we were top Canadian in category 3A. the "other" club made a late submission and we dropped to second place. Not bad for such a young club.

We had our first auction at North Surrey Senior Secondary School. It proved to be quite interesting and lots of fun on the sidelines.

1978 - 1979

President ------- Carl Bertholm, VE7CLC
Vice Pres. ------ Mike Heritage, VE7CLE
Secretary -------- Joan Gendron, VE7CTB
Treasurer --------- Jim Johnson, VE7CSJ

This was a very active year starting with an over subscription of new students. Max Green, VE7DZ took over the duties of teaching theory.

Prior to the start of regular meetings, the club held a picnic for members and families at Port Kells Park on August 27th.

The club held its first Flea Market at the Hjorth Road Hall, Sunday October 15, 1978. It was considered a great success as we had buyers and sellers from all over the lower mainland.

The annual Christmas party was held at St. Helen's Church hall with Woodwards doing the catering.

Fred, VE7CJG took charge o the bunny hunt with a borrowed bunny from BCFMA. It was not too popular a project and this was attributed to the fact that for some unexplained reason Cary, VE7CFC kept winning.

A successful pre Field Day trial was held at Surrey Place with the aid of the Gendrons' motorhome. There was a Teletype display in the mall with Cary, VE7CFC sending pictures from his QTH in Delta.

The club purchased a generator and a 204BA monobander for use on Field Day. Field Day was held again on the excellent site on top of old Monkey mt. Carl, VE7CLC and Mike, VE7CLE were responsible for the well being (food wise) of all those who participated. And we did come first in Canada and I believe eleventh overall in the 3A category. This was a perfect ending to a great year of Hamming.

The club Bulletin was conceived by Bob Searle, VE7CHB, nurtured by Doug Moore, VE7CBM and finally adopted by Carl Bertholm, VE7CLC. It has proved a very valuable asset to the club.

Our big venture was the Club Certificate commemorating Surrey's 100th birthday. This was a great success thanks to the hard work of Cecil Boggis, VE7YM in making so many contacts and Doug, VE7CBM taking care of all the paper work. Certificates were sent to England, France, and South America, Australia and practically every state in the United States. The project was made possible by a grant from the Surrey Centennial Committee and the assistance of Fred, VE7CJG and Carl, VE7CLC in the printing.

1979 - 1980

President ------- Bill Driscoll, VE7ARL
Vice Pres. --------- Al Neufeld, VE7CDC
Secretary --------- Mike Foster, VE7ACZ
Treasurer --------- Lee Hopwood, VE7BDZ

Another great year for the club. Fred, VE7CJG built a bunny and conducted several hunts. They just never caught on as we had anticipated. Maybe a new twist is required.

Two Flea Markets were held at Hjorth Hall one in October and the other in March. They appear to be very popular with Hams.

The club took part in the PNE Amateur Radio booth. The portable tower and beam were put to good use.

The annual Christmas party (dinner & dance) was again held at St. Helen's Church hall. It was well attended.

The club set up a working station, VE7SAR in Bear Creek Park as part of the celebrations for Heritage day. The Gendrons, Joan & Len, again graciously made their motor home available. The club also provided communications for the Delta Family Days.

Due to more than unusual road conditions up Monkey Mountain, Field Day was staged on the property of Joe Chesney in Langley. Our generator refused to cooperate so Ralph, VE7PWA, supplied ni-cad batteries. Fred's generator kept everything charged up. The new 4-element 15-meter monobander made Fred, VE7CJG and Jim, VE7CSJ was given a good tryout. Mike, VE7CLE was responsible for procuring all the materials for the beam.

1980 - 1981

President ------- Fred Orsetti, VE7CJG
Vice Pres -------- Cary Miller, VE7CFC
Secretary ------ Chris Johnson, VE7FFJ
Treasurer -------- Lee Hopwood, VE7BDZ

The club switched from the Electronics room to ordinary classrooms at North Surrey Secondary. But due to the strike by CUPE members, we were obliged to meet part of the time in the Main Library in the Guildford area.

Max, VE7DZ is still successfully preparing students for the amateur examinations.

This was the term when we finally got contact with EMO through the persistent efforts of President Fred.

No bunny hunts were held but there were two Flea Markets in operation again.

The Christmas Party was held at the Scandia House in Walley. The restaurant has since blown its finals and is no longer in operation. Olaf Saetre, VE7CIS, arranged the party.

The Field Day site was back on Monkey Mountain, Carl, VE7CLC and Mike VE7CLE again took care of the mess tent. An added feature was the presence of the Scout troop from Cloverdale for the purpose of helping to set up and take down the tents and equipment. They also provided Mrs. Murphy's parlour. The total points accumulated were not the great but all who participated had a super time.

'Get On The Air'

'Improve Your Signal' Presentation

Our first SARC General Meeting of 2020 was Wednesday, January 8th. 

One of our best attended presentations ever

As a result of feedback from our Basic courses, we planned a presentation and panel discussion around the basics of getting started in Amateur Radio. This was intended not only for new Hams but also those looking to improve their station capabilities.

We covered primarily VHF/UHF gear, antennas, power and accessories. Based on the interest in this session we will host a similar topic focusing of HF later in our meeting schedule.

We asked our SARC members to bring along any good used gear for sale and a few items showed up.

By request, here is the slide deck from the presentation:
https://drive.google.com/file/d/1TkZWzDsznMV1hbcq69Jwtn9AxSp3MCXW/view?usp=sharing

We hope to have an accompanying guide available here shortly.

~ John VE7TI

Back To Basics: Overmodulation

Overmodulation Leads To Interference!

Question B-001-019-003 (A) - From the Canadian Basic Question Bank:

An amateur station using radiotelephony must install a device for indicating or preventing:

a. overmodulation 
b. resonance 
c. antenna power
d. plate voltage

The  key word here is must. All four of the above can be measured in a transmitting station but not all are required to be indicated or prevented. Only one is harmful to the extent that it can seriously affect enjoyment of the airwaves and cause interference to other Amateurs.

Overmodulation is the condition that prevails in telecommunication when the level of the modulating signal [the intelligible portion holding information— such as spoken audio from a mic] exceeds the value necessary to produce 100% modulation of the carrier. A carrier signal is one with a steady waveform, constant height (amplitude) and frequency shown in the diagram as the envelope. Modulation is superimposed on the carrier at the transmitter and recovered at the receiver.

In layman's terms, the signal is going "off the scale". Overmodulation results in spurious emissions by the modulated carrier, and distortion of the recovered modulating signal. This means that the envelope of the output waveform is distorted. The usual way of ensuring you are not over-modulating is to use the ALC on your HF radio, which will tell you if the audio level is too high.  It is also good practice to monitor your own audio while transmitting to ensure you are not too close to the mic or speaking too loudly, as the presence of distortion will be a sure sign that your audio is driving the transmitter too hard.

In the diagrams above, A indicates an Amplitude Modulated (AM) signal that is modulated to a low percentage. When modulation is increased to 100%, as in B, we are on the threshold of overmodulation. When increased above 100% as in C, the signal is said to be overmodulated resulting in distortion and spurious emissions.

See a demonstration here on YouTube.

There are several questions on overmodulation in the question bank and one is always on the Basic exam.

Resonance is a desirable state when tuning to a specific frequency but does not have to be measured.  Antenna power and plate voltage may be measured but that is also not mandatory.

The correct answer to this question therefore is ‘A’ Overmodulation.

More information on overmodulation? 

https://books.google.com/books

~ John VE7TI

New Year's Resolutions: 2020 Edition

Happy New Year!

The New Year has arrived and Hams, like so many others, may have a few resolutions to consider. I think we all recognize that the hobby is going through change. While the number of licensed Amateurs in North America continues to increase, likely due in large part to the ease with which a license exam can be passed, the number of ‘active’ hams seems to be diminishing. One only has to monitor a repeater or tune in to a weekly net to realize that participation has dwindled. With this in mind, I offer a list of amateur radio new year’s resolutions and encourage you to try to adopt some or all with your own goals for 2020.

On the west coast we hear about the impending ‘300-year’ earthquake frequently and have regular drills to prepare, including checking into an emergency net. That earthquake could happen tomorrow or at some point past our lifetime—despite some believable scientific data, no one knows for sure. But there are more common calamities that could happen sooner, and have over the past few years. A major snow or wind storm… an extended power outage.

"Five minutes before the party is not the time to learn to dance"

It is a good idea to make preparations now without the stress of a fast approaching deadline. If you are thinking of replacing or building an  antenna for use in an emergency, now is the time to build it and test it out at a leisurely pace. We have in the past, and will continue to present, home built antenna projects in SARC publications. If you’re not that handy, ask about the antenna workshop we offer to all our Basic course students. We also have a cadre of willing ‘Elmers’ who will help you with advice and assistance to set up that antenna.

Another aspect of Amateur Radio that comes into focus now is contest season. There is a contest every weekend in January, just check the calendar on: https://www.contestcalendar.com/. 

SARC has a contest group with tutors, and we invite your participation. Even if you only have a passing interest in contesting, come and try it at least once. Emergency focused radio operators will find contesting has many of the same challenges, and you will improve your skills, thereby becoming a better communicator.

Have a go at operating away from your usual location. It has been dubbed “Ham Radio Alfresco." There are so many hills, parks and beaches in our area that if you can’t find a place to throw a little wire in a tree and operate with low power off a battery, you aren’t looking hard enough. Your “portable” station can be anything from a  handheld or QRP single band rig to one of the big three’s latest 100 watt wonder radios that do everything from DC to Daylight. Just turn the power down so the battery lasts more than 10 minutes and you too can add another few ‘Qs’ to your logbook.

If you are thinking about trying to upgrade your license, now is the time to start studying. If your storage shed has a ton of old radio stuff in it, get busy and drag it all out into the sunlight and sort it out or throw it out. If you find you have a working radio or accessory that you do not need any more, consider donating it to your local Amateur Radio group. 
Come to a monthly meeting. You will find interesting presentations, lots of information and friendly fellow SARC members.

And lastly, please make an effort to use our repeaters once in a while. It would be very encouraging to hear some conversation outside of net night but, speaking of our net, please check in there too, we meet every Tuesday at 8pm 147.360 MHz (+600 KHz) Tone=110.9, or via Echolink.

73, and Happy New Year!

~ John VE7TI, Editor