Thursday, October 18, 2018

JOTA / JOTI Scouts On The Air This Weekend



Media Release

SARC, SEPAR and LARA will be providing communications

Scouts Unite the World!
Demonstration of Emergency Communications Saturday, October 20

Surrey, BC  October 18, 2018 – Jamboree On The Air and Jamboree On The Internet (JOTA-JOTI) is the largest Scouting event in the world with over 1.8 million Scouts participating across 150+ countries.  Scouts and Guides across the world connect with each other during JOTA-JOTI using the airwaves and the Internet.

Despite the Internet, cell phones, email and modern communications, every year whole regions find themselves in the dark. Tornadoes, fires, storms, landslides, ice and even the occasional cutting of cables leave people without the means to communicate. In these cases, the one consistent service that has never failed has been Amateur Radio. These federally licensed radio operators, often called “hams” provide backup communications for everything from community events to local Emergency Operations Centres and even for the International Space Station. Surrey and Langley “hams” will join with local Scouting groups showing them their emergency capabilities this Saturday at Camp McLean, located at 20315 16 Ave, Langley, B.C.

JOTA/JOTI is an annual World Scouting event that was first held in 1957. The event unites Scouts with their Scout friends world-wide. The purpose is to meet each other, exchange ideas, learn from each other, and gain mutual understanding. Contacts between the Scouts are made via Amateur Radio and in a supervised Internet chat room. The youth attending will also learn about radio communication and Internet safety. Scouts Canada gives special thanks to the Surrey Amateur Radio Club, the Langley Amateur Radio Association, and the TELUS Wise® team for volunteering their time to facilitate this great event.

Over the past year, the news has been full of reports of ham radio operators providing critical communications during unexpected emergencies in towns across North America including B.C. wildfires, winter storms, landslides and other events world-wide. When trouble is brewing, Amateur Radio’s people are often the first to provide rescuers with critical information and communications. On the weekend of October 20-21, Lower Mainland Scouts will have a chance to meet and talk with Surrey and Langley’s ham radio operators to see for themselves what the Amateur Radio Service is about, as Scouts worldwide take to the airwaves using both voice and digital communications. There are also planned demonstrations of satellite contacts, Morse code training and hidden transmitter hunts to give participants a chance to experience all facets of the hobby.

Amateur Radio is growing in Canada. Recent amendments no longer require Morse code, although it is still used in the hobby. Amateur Radio is practiced as a hobby, as a sport, and as a reliable means of communications by outdoors enthusiasts and others, where cellular telephone towers do not exist. There are now over 30,000 Amateur Radio licensees in Canada, and more than 2.5 million around the world. Through the Amateur Radio emergency services program, ham volunteers provide both emergency communications for thousands of provincial and local emergency response agencies and non-emergency community services too, all for free. 

For more information about Scouts Canada, go to http://www.scouts.ca
For more information about JOTA/JOTI, go to https://www.jotajoti.info





For more information about The Surrey Amateur Radio Club, go to http://ve7sar.net




For more information about the Langley Amateur Radio Association, go to https://lngara.wordpress.com







Planned Activities   (Scout groups will rotate through these activities between 9am and 5pm on Saturday)

1.  Introduction to Amateur Radio

2.  HF Station 
  • Worldwide communications using the 100 ft mobile tower
  • Attempt to contact other Scout groups worldwide
3.  VHF/UHF Station
  • Contacts with other Scouting groups worldwide using both voice and digital modes
4.  Public Service/Emergency Communication 
  • Supervised hands-on communication exercise within camp area using radio
5.  Foxhunt
  • A Radio ‘Sport’
  • Hidden transmitter hunting techniques
  • Search for 2 foxes within the woods surrounding the camp
6.  Morse Code (CW) and Phonetic Alphabet
  • Using worksheet, practice sending name
  • Using worksheet, print and learn to say name using phonetic alphabet 
7.  Satellite Contact 
  • There are 5 daytime opportunities throughout Saturday to make an orbiting satellite contact
Any Scouting group wishing to make contact, we will be monitoring the suggested HF frequencies and can be contacted on VE7RSC 147.360MHz+ tone 110.9Hz or  IRLP node 1736, or our Echolink node number for VE7RSC-VHF: 496228



Monday, October 15, 2018

Early Amateur Radio In The Canadian Arctic



A Communicator Reprise: September 2013


Amateur Radio (aka Ham Radio) has been a way for almost 100 years for citizens to communicate wirelessly to distant locations. The hobby is still thriving and providing opportunities for experimentation in radio electronics and the operation of shortwave radio stations. In the 1930s people working in Canada’s Arctic often brought their amateur radio skills and equipment north with them so that they could relieve the isolation by contacting other radio operators around the world.

Recently a ham radio colleague, Bill Little (VA7ZBL), came across a collection of QSL cards from and old operator (Art J. Cook, VE4KZ, who lived in Calgary Alberta) that contained some from the far north of Canada. In their own way they give a glimpse into the history of the region and some of the people who worked there before the Second World War.
For those not familiar with Ham Radio – a QSL card is personalized postcard–sized acknowledgement exchanged by amateur radio operators to confirm the radio contact (or QSO in radio jargon) with each other. These cards from the Arctic would have been highly prized by the recipient as ham operators were very rare in those days – and even today there are not many of them active.

Radio Station VE5TV (1937), located at Nottingham Island, Northwest Territories
(in the former District of Franklin.) (
Photo from the MacFarlane collection
)

This station, operated by Dick Vaughan and Coll Baldwin was located on Nottingham Island. This location (Inuktitut: Tujjaat) is an uninhabited island in the Qikiqtaaluk Region of Nunavut, Canada. It is located in Hudson Strait, just north of the entrance into Hudson Bay. A weather station was constructed on the island in 1884. In 1927, an airfield was constructed as part of a program to monitor ice in Hudson Bay. The island became uninhabited in October 1970 as Inuit residents migrated to larger towns, primarily Cape Dorset. Presumably the operators of the radio station were staffing the weather station.

Each radio call sign was unique to a licence holder. The call sign was synonymous with the licenced holder. Successful contacts were later confirmed with a QSL card, sent by mail, as confirmation or proof of the contact. These cards are highly prized by radio operators, and these cards from Canada’s Arctic were and still are very rare.


VE5OA (1936) located at Fort Norman, Northwest Territories.
(Photo from the MacFarlane collection)



VE5MR (1936) located at Fort Norman, Northwest Territories.
(Photo from the MacFarlane collection)

VE5MR was Hugh Ross and VE5OA was F.J. Rapp who worked for Canadian Airways. Fort Norman is now known as Tulita, a hamlet in the Sahtu Region of the Northwest Territories, located at the junction of the Great Bear River and the Mackenzie River.

VE5QB (1937) (Photo from the MacFarlane collection)

VE5QB was operated by E.A. Kirk (I don’t know what his affiliation or occupation was at this site). Old Crow is located on the Porcupine River in the far north of the Territory.

VE5LD (1937) located at Gjoa Haven, on King William Island.
(Photo from the MacFarlane collection)

VE5LD (1937) was operated by Donald Graham Sturrock (1914-1943), who was an Apprentice Clerk with the Hudson’s Bay Company at Gjoa Haven 1935–1938. He also operated the Hudson’s Bay Company radio station, call sign CZ2L, on 69 meters. He notes on his QSL card that his station is a very low power, 10 watts, and brags that he has contacted stations all over the world.

Sturrock (VE5LD) was one of the discoverers of relics and human remains of the doomed Franklin expedition. He was referred to in the article about the painting of the RMS Nascopie by Thomas H. Beament. Sturrock afterwards became the Wireless Operator in the HBC vessel Fort Ross (1939–1941), and his ham radio work obviously set the groundwork for this employment. He resigned from the HBC to join the Royal Canadian Air Force (RCAF) in 1941. He was declared missing and presumed killed after operations over Central Burma on 29/05/1943.

Gjoa Haven, (Inuktitut: Uqsuqtuuq). The name Gjoa Haven is from the Norwegian and was named by polar explorer Roald Amundsen after his ship Gjoa. Permanent settlement at Gjoa Haven started in 1927 with a Hudson’s Bay Company outpost.


References:
http://en.wikipedia.org/wiki/Nottingham_Island
http://en.wikipedia.org/wiki/Tulita
http://en.wikipedia.org/wiki/Old_Crow,_Yukon
http://en.wikipedia.org/wiki/Gjoa_Haven,_Nunavut
http://www.gov.mb.ca/chc/archives/hbca/biographical/s/sturrock_donald-g.pdf


Author’s Note: My thanks to Bill Little for the cards. I am also grateful to George Duddy for additional information included in the article.

~ John M. MacFarlane VA7PX




Thursday, October 11, 2018

Learning Morse Code After Getting My Licence



A Communicator Reprise: February 2013



It is clear to me that the use of Morse code is holding its own on the ham bands. Further, I’m meeting hams who have recently become proficient in Morse and are making QSOs on air – something that I have want to do for a long time.



In 2004, when I determined to get my ham licence (after thinking about it since 1961) I began learning Morse code.  I took the test and passed the Morse test soon afterwards (before I got my call sign). Almost immediately the Morse code requirement was dropped and it has remained as an optional method of achieving HF privileges. I did not use CW on air and soon lost my capability to copy and send.

With encouragement from John Brodie I recently began practicing again – and am now practicing up around 6-8 words per minute.  I have been using an excellent free Morse tutor created by a New Zealand ham ZL1AN which I would recommend to any ham thinking of learning morse. The link is
http://www.qsl.net/zl1an/Software/teach4software.html

Another learning tool that has been very useful is a website sponsored by AA9PW on which there are a number of options – copy text sent at a range of speeds – which I use to practice copying – and to gradually pick up my speed. The link is http://aa9pw.com/morsecode/ This is a slick resource which has changing content every day.  There is also a podcast which can be subscribed – to download the “Quote of the Day” at a range of different speeds. This allows me to copy when I have a few free moments – and with an earphone it is very private.

Several times a week I make a Skype connection with Brett Garrett or John Brodie and we each send and receive for about 10 minutes each – just allowing the computer microphone to pick up the sounds from a keyer run by a paddle. This is tougher than working with machine sent code – as humans are not as consistent and methodical – and this really puts me to the test. They are both very patient with me – and I find my speed is picking up.  Mostly my confidence is increasing – and I expect to start making local slow speed contacts on-air very soon. Maybe there will be enough interest to start a slow speed contact group?

I find that the practice is keeping my brain agile – forcing me to use brain capacity which has grown idle – and if nothing else it has slowed the effects of aging. I highly recommend learning Morse even if you never plan to use it on air – and take advantage of the free resources on the web to help you along.

~ John MacFarlane VE7AXU



Sunday, October 7, 2018

You Might be Addicted to Ham Radio if:



Not sure where this originated but it was forwarded by a reader... 

1. When you look at a full moon and wonder how much antenna gain you would need.

2. When a friend gets a ride from you and remarks that you have a lot of CBs in your vehicle, it turns in to an hour long rant on how ham radio is not CB radio.

3. When someone asks for directions, you pause; wondering if long or short path would be best.

4. When you can look at a globe and be able to point to your antipode (and you know what an antipode is). Cool antipode map at http://www.antipodemap.com/

5. Your cell phone ring tone is a Morse code message of some kind

6. You have accidentally said your Amateur Radio call sign at the end of a telephone conversation.

7. Your favorite vacation spots are always on mountain tops.

8. You notice more antennas than road signs while driving your car.

9. You have driven onto the shoulder of the road while looking at an antenna.

10. Porcupines appear to be fascinated with your car.

11. If you ever tried to figure out the operating frequency of your microwave oven.

12. When you look around your bedroom of wall to wall ham gear and ask: Why am I still single?

13. The local city council doesn't like you.

14. You think towers look pretty.

15. Your family doesn't have a clue what to get you for Christmas, even after you tell them.

16. Your HF amplifier puts out more power than the local AM radio station.

17. The wife and kids are away and the first thing that goes through your head is that no one will bother you while you call "CQ DX" a few hundred times.

18. When you pull into a donut shop and the cops there on their coffee break ask if they can see your radio setup.

19. You refer to your children as your "Harmonics".

20. Your girlfriend or wife asks: "You're going to spend $XXXX on what???

21. You actually believe you got a good deal on eBay.

22. When you see a house with a metal roof and your only thought is what a great ground plane that would be.

23. You have pictures of your radio equipment as wallpaper on your computer's desktop.

24. Every family vacation includes a stop at a Ham radio store.

25. The first question you ask the new car dealer is: "What is the alternator's current output"?

26. You buy a brand new car based on the radio mounting locations and antenna mounting possibilities.

27. You have tapped out Morse code on your car's horn.

28. A lightning storm takes out a new Laptop, Plasma TV, and DVD Recorder, but all you care about is if your radios are okay.

29. Your wife has had to ride in the back seat because you had radio equipment in the front seat.

30. Your wife was excited when you were talking about achieving that critical angle, but very disappointed when you finally did.

31. During a love making session with your wife, you stop to answer a call on the radio.

32. Your wife threatens you with divorce when you tell her that you are going on a "fox" hunt.

33. Talking about male and female connectors makes you feel excited.

34. You dream of big, comfortable knobs, but not on women.

35. You always park on the top floor of the deck, just in case you might have to wait in the car later.

36. When house hunting, you look for the best room for a radio shack and scan the property for possible tower placement.

37. When house hunting, you give your realtor topographical maps showing local elevations.

38. The real estate agent scratches his head when you ask if the soil conductivity is high, medium, or low.

39. You have Ham radio magazines in the bathroom.

40. When your doorbell rings, you immediately shut down the amplifier.

41. Fermentation never enters your mind when "homebrew" is mentioned.

42. Instead of just saying no, you have said "negative".

43. You have used a person's name to indicate acknowledgement.

44. You become impatient waiting for the latest Ham Radio Outlet catalog to arrive.

45. You have found yourself whistling "CQ" using Morse code.

46. You always schedule the third weekend in June for vacation.

47. You walk carefully in your back yard to avoid being close-lined.

48. You have deep anxiety or panic attacks during high winds or heavy ice.

49. You and the FedEx/UPS men are on a first name basis.

50. You really start to miss people that you've never seen.

51. Your exercise machine is a Morse code keyer.

52. You walk through the plumbing section at the hardware store and see antenna parts.

53. Your neighbors thought you were nuts when you ripped up your lawn to bury chicken wire.

54. Your next door neighbor thinks that your wife is a widow.

55. Your wife has delivered meals to your Ham shack.

56. If you sold all your Ham radio equipment, you could pay off your mortgage.





Thursday, October 4, 2018

Frequency Coordination In BC


A Communicator Reprise: November 2012


Our VHF and UHF bands are subdivided into sub-bands while the ones used for FM and digital communications are channelized. Certain sub-bands are allocated to channelized repeaters and simplex communications, resulting in a fixed number of channels in each band. This limits the number of repeaters and simplex channels available for use, but on the other hand, with coverage being generally limited to line-of-sight distance, these channels can be reused many times across the Province.

Early in the development of VHF repeaters it became evident that some form of organization needs to ensure that repeaters do not interfere with each other while the use of the available spectrum is optimized so that the greatest number of repeaters can be accommodated in the limited space available. The result was the emergence of Frequency Coordination Councils, groups of amateurs who volunteer and take it upon themselves to manage the repeater portion of the band, coordinating frequencies so as to prevent interference. Frequency Coordination is the process of choosing and recommending one or more specific frequencies for a system that will operate on fixed frequencies, such as a voice repeater, an ATV repeater, a packet system, a remote base or link, etc. 

In BC, the British Columbia Amateur Radio Coordination Council (BCARCC) was incorporated in January 1995 and is the current coordinator of VHF and UHF frequencies. It has taken its band plan from the Radio Amateurs of Canada (RAC) band plan and modified it to dovetail with one adopted by the Western Washington coordinators. Repeater operators and clubs who sponsor repeaters work with the Council to find and establish frequencies for their repeaters. The complete list of BC repeaters can be found at their website, www.bcarcc.org

Coordination councils in Canada have no power of enforcement: they depend on the respect and cooperation of those they serve. Over the years, BCARCC has gained the credibility and respect of virtually all Hams and has worked with all repeater operators. Amateurs cooperate with BCARCC because this approach to the use of these bands for fixed frequency installations has proven to be a workable and effective method, for everyone's benefit. 

In November 1996, BCARCC and Pacific Region of Industry Canada (IC) signed a Memorandum of Understanding (MOU) to establish the advisory role of BCARCC versus the legislative and regulatory role of IC. Under the MOU, IC refers all applications for repeaters to BCARCC for coordination, and no longer lists specific frequencies on Amateur licenses (reflecting the fact that no Amateur is licensed to have exclusive use of a frequency). 

Coordination requires cooperation: Although our Amateur sub-bands are a finite resource, they can support a large amount of fixed-frequency activity if shared in a harmonious and cooperative manner.  Abuse can destroy the resource for everyone. BCARCC provides the resources to manage our spectrum. BCARCC has other responsibilities besides frequency coordination. For example, it is involved in mediating interference issues, band planning, working on approaches to solving technical problems, and communication and cooperation with neighbouring coordination councils as well as working with other local and national organizations.

BCARCC’s success over the long term has, in part, been the result of policies that differ significantly from those of other coordination councils: 

  • Unlike other councils whose members are repeater operators, BCARCC’s members are Ham clubs. This ensures that policies are developed to benefit the Ham community, not only the interests of repeater operators.
  • Coordinations are completed based strictly on technical factors: can the repeater provide the coverage on the specified frequency without causing harm to other systems? The purpose of the repeater, the number of Hams it will serve or the identity of the operator (as long as he/she has an Advanced License) have no bearing on the coordination.
  • The BCARCC executive and its Board of Directors determine policy and provide direction. Coordinators are appointed for their technical competence and work independently, based on these policies. Policies are documented at www.bcarcc.org/policies
  • BCARCC has area coordinators in various regions of our Province. These coordinators provide local knowledge and help those wishing to install repeaters with frequency selection and other technical issues.
  • BCARCC considers itself to be an enabler that provides support for the enjoyment of the hobby, not as a regulator and not as a curb on Ham activities.
  • BCARCC is fortunate to have the support and continued involvement of retired, professional, communications engineers who ensure that policies are appropriate and who work with repeater operators to resolve technical and interference issues. 

More than 450 repeaters are coordinated in BC. These repeaters are also known to coordinators in Washington State as well as Alberta and the Yukon and can therefore be protected from other users of the frequency. Over 150 simplex nodes have been registered. Simplex stations, such as Echolink, IRLP, APRS and point-to-point links are registered, meaning that their presence is published. It is hoped that Hams respect their presence although simplex stations cannot be assured of protection from other users of the frequency.

A complete list of coordinated and registered stations is available at www.bcarcc.org. These lists are in pdf format and can be printed.  Feel free to make contact regarding coordination issues.

~George Merchant VE7QH 
  ve7qh@shaw.ca


Sunday, September 30, 2018

The October 2018 Communicator


Here is the latest Communicator 

Amateur Radio News from the South West corner of Canada and elsewhere. You will find Amateur Radio related articles, profiles, news, tips and how-to's. You can download it as a .PDF file directly from https://goo.gl/JmpT1u


https://goo.gl/JmpT1u




As always, thank you to our contributors, and your feedback is always welcome.  My deadline for the November edition is October 22nd. If you have news or events from your Vancouver area club or photos, stories, projects or other items of interest from elsewhere, please email them to the communicator@ve7sar.net

Keep visiting this site for regular updates and news.

~ 73,
  John VE7TI
  Communicator Editor

Friday, September 28, 2018

My Antenna Adventures - An OCF [Part 2]



A Communicator Reprise: June 2013


The RF Demons Are Finally Exorcised

I purchased the Carolina Windom 80 antenna from Radio Works with the idea of using it on 80 and 40 m to supplement my SteppIR vertical, which covers the 6m-20 bands. Being 133 ft. long, it is a full ½ wave for 80 m and advertised as usable on the higher bands.  One of its distinguishing features is a “vertical radiator”, a 22 ft. length of 50 ohm coax connected off-centre to the horizontal radiator by way of a 4:1 balun.  At the lower end of the vertical radiator is a choke balun (or “isolator”), there for the purpose of discouraging radiation from the remainder of the feedline connected to the transmitter.    Presence of the vertical radiator, it is claimed, changes the radiation pattern to give a low angle component, good for DX.  When I searched the web for comments on this antenna, virtually all indicated that the owners were happy with its performance and would recommend it to others.  I had some challenging issues when I put the Carolina Windom up at my QTH.

I have a number of tall trees on my property, but only one not-very-tall tree suitable for anchoring one end of the wire at the front of the lot.  At the rear of the lot are several taller trees, none of which is ideally situated to anchor the opposite end of the wire.  Nevertheless, I used SARC’s air cannon to fire a line through one of these trees about 50 ft up.  When we raised the antenna, both ends of the wire came close to branches, which raised the concern that they might affect the performance.  In addition, another tree near the middle of the lot had drooping branches that came very close to, and sometimes touched, the suspended wire.

I then proceeded to make some measurements using an  MFJ-269 analyzer.  The MFJ reads not only SWR but also the components of Z (impedance), which are Rs (radiation resistance) and Xs (reactance).  When I pulled the antenna up to full height into the trees, the measured SWR was above the range of the MFJ  (>31) over most bands.  Rs (which I expected to be around 50 ohms) was zero nearly everywhere. I then repeated the readings with a Comet CAA-500 analyzer with the same result: every SWR reading on every band was off-scale.   Clearly, something was wrong.   When I transmitted and put power into the antenna, sometimes I could tune it with the radio’s tuner and other times I could not.  The antenna was then taken down and all parts checked to see if there was a faulty component.  Both baluns tested OK, the coax connected to a 50 ohm dummy load appeared good, and all solder joints seemed to be sound.   I even substituted known good baluns for the ones provided but nothing changed for the better.

I then commenced my email correspondence with Jim, the Radio Works guy to explain the symptoms.  He was puzzled by the results and after several emails back and forth, suggested I return the antenna to them for checking, which I did.  I received it back within a few weeks after Radio Works had replaced the vertical radiator because of a suspected intermittent connector.  The winter months went by before I put the antenna up again, and began testing to see the results.  In the meantime, as related in the previous posting, I had acquired an AIM 4170 antenna analyzer and used the time to get familiar with its many features. I ran the AIM through some tests with my other (resonant) antenna and confirmed that the MFJ and the AIM gave almost identical results for SWR and the components of impedance (Xs and Rs).  

Now for the Windom.

Figure 1 shows the initial setup.  The antenna was about 35 ft. off the ground at one end and 50 ft at the other.  60 ft of 50 ohm RG213 transmission line connected the line isolator to a surge protector and station ground at the house entrance panel, then to an external swr meter and the transmitter. 


Figure 2 shows the results of SWR measurements across all bands from 3 to 30 MHz (note: the amateur bands are highlighted).  The SWR trace displayed dips at certain frequencies but mostly not where they should be. 


Figure 3 shows the results of several re-scans for the 80 m band, and 

Figure 4 for 20m – every re-scan gave a different pattern.  When I tried putting power into the antenna from the transmitter, it usually would not take power or, if it did, it was only momentary while the internal tuner kept searching for a match on each key-down.   The results were no better on other bands, and rainfall also made things even worse.

As I struggled to find the reason for this odd behaviour, the only change that seemed to bring improvement was disconnecting the station ground. 

Figure 5 shows the result for the 80m band under both conditions.  This was possibly an important clue.

Since I had thought that the interfering branches might be affecting resonance (as they blew in the breeze), my next move was to have the trees pruned to eliminate the offending branches. At the same time, I got the tree guy to install a rope and pulley system (made from bicycle inner tubes, shackle and pulley) around the trunk of two select trees about 40 ft. up so I could raise and lower the antenna at will.  The wire, 4:1 balun and coax were then raised using the pulley.   The spacing between the trees did not permit the wire to extend full length, so I put a drop leg on the short end of the wire and pulled it taut.  The coax connected to the “middle” tree followed the trunk vertically down to ground level, snaked in a circuitous route across the garden and up into the second floor shack.  This required double the length of coax compared with the previous arrangement.  As before, the coax outer conductor was grounded at the entrance panel surge protector but this time I added a choke balun at the entrance panel by coiling up the extra 15 ft of coax, which I connected to the transmitter by a 15 ft jumper. 


Figure 6 shows the new configuration.


Figure 7 shows the 3-30 MHz scan, and 

Figure 8 the 80 m scan after these changes were made.  

The SWR across all frequencies and especially within the amateur bands was much lower and mostly below 3;  successive re-scans of SWR, Xs and Rs gave virtually identical results.  The SWR was now acceptable on most of the 80 m band and the match to the transmitter was stable.   Other bands (except 10 m) showed SWR 2-4, higher than I would prefer, but within the range of most internal radio tuners and a definite improvement over the initial results.  Also comforting was the fact that my external SWR meter connected to the transmitter (under power) displayed the same SWR as did the AIM.

To effect this dramatic improvement, I had made a number of changes all at the same time.  So I started undoing the changes one-by-one to determine which was the critical one.   I had previously confirmed (to my surprise) that the pruning of tree branches had no discernible effect.  Lowering the centre of the antenna to its previous height did not do it.  Removing the ground at the entrance panel had no effect, nor did uncoiling the choke balun.  The only way I could recreate the original problem was when the antenna was lowered to its original height, the feedline was shortened from 120 ft. to 60 ft. and the coax was allowed to make a drooping loop from the antenna to the shack rather than falling vertically from the antenna and taking a circuitous route to the shack.  Now this does not provide a technical explanation of the problem; it only explains what had to be done to fix it.  I do believe that I had RF on the feedline initially.  What have I learned from this experience?
  • Get the antenna as high as possible
  • Make sure the feedline drops down vertically to the ground
  • Change the length of the feedline if there appears to be a serious mismatch

There is one further puzzling footnote to this situation: Even after the aforementioned improvements, the MFJ meter consistently reads higher – by a large margin – than both the AIM and the external SWR meter. 

For example, on 80 m, an SWR of 2 on the AIM reads 8-15 on the MFJ.  Xs and Rs also disagree with the AIM, with Rs equal or close to zero on the MFJ most of the time.  I am interested in thoughts of our more knowledgeable members regarding all of the foregoing.  However, at least now I have an antenna I can use.

~ John Brodie VA7XB





CQ CQ CQ

JOTA / JOTI Scouts On The Air This Weekend

Media Release SARC, SEPAR and LARA will be providing communications Scouts Unite the World! Demonstration of Emergency Communic...

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