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Showing posts with label 6m. Show all posts
Showing posts with label 6m. Show all posts

2022-11-13

Remembering Jim Smith VE7FO - SK

 We have lost another of the 20%

Looking back, it is ironic that Jim wrote the following about Brett Garrett VE7GM when Brett passed away in August 2018

"They often say that 20% of a given membership do 80% of the work... Brett was one of the 20%, no, more like 5%. An active member of both the Surrey Amateur Radio Club (SARC) and Surrey Emergency Program Amateur Radio (SEPAR), Brett freely shared his knowledge and led Surrey Amateurs to two very successful Field Days."

I can attest to the same about Jim Smith VE7FO and his involvement with VECTOR and SARC.


Jim VE7FO is now a Silent Key

I first became aware of Jim when I laid the groundwork for the Vancouver Emergency Community Telecommunications ORganization (VECTOR) around 1999. Jim lived in the Dunbar area of Vancouver, and I became aware of his involvement with the Point Grey club, and that he was very knowledgeable about HF.

Jim was an avid contester who enjoyed working all modes -- especially CW and RTTY. A true mentor at heart, he often hosted "newbies" at his Vancouver home to introduce them to contesting. Many a new contester was given real experience operating "in the fray" and encouraged to keep honing their skills.

That knowledge translated into a very successful series of first Field Days for VECTOR. Jim also took on the project of planning the HF tower and antennas at e-Comm, the regional 9-1-1 and dispatch centre. That facility also houses the Vancouver EOC and its Amateur Radio component. Jim was a terrific resource in suggesting what might and might not work for that location, and he got that tower completed and functional. It was also Jim who persuaded me to look at offering our own Basic Amateur Radio classes. Well... 22 years later we are still offering them with the same basic content that we worked on back then, except now they are provided by Surrey Amateur Radio Communications (SARC), on-line, with successful students across Canada and even graduates abroad.

VECTOR Field Day (about 2003) Jim VE7FO as Station Manager in the new VECTOR bus.
Fred VE7CX in the foreground.

Around the time that I left VECTOR for the SARC group in 2004, Jim decided that he too would become a member of SARC. What followed was a mentorship program to introduce new members to contesting, one of Jim's passions. I spent many hours at his QTH working various contests under Jim's expert tutelage.

Myself (VE7TI) and Jim VE7FO. I'm being taught the fine points of contesting.

In one of many articles written for our SARC newsletter 'The Communicator', Jim wrote:

"My own involvement with SARC started when I was recruited by John VE7TI, as a Field Day operator. There are many enjoyable ways of conducting FD which range from everyone sitting around the BBQ, telling stories and making a few contacts to the hard-core contest style where everybody goes all out to WIN. I was told that it would be a hard core, win for Canada situation.  Being a hard-core contester myself I took the bait.

Well, it turned out that the operators, while enthusiastic, didn't have the HF contest experience necessary to achieve the goal.  Nonetheless, it was obvious that the potential was there so, once FD was over, I joined the Club and made a FD training proposal to the Exec with the goal of winning for Canada, which was accepted. 

This training started in October and ran until next year's FD.  It consisted of many formal training sessions including classroom style and participation in the major contests, during which the ops received coaching on the operating techniques for maximizing the number of contacts per hour.

This would be a very significant investment of time for the trainees. This "Get Your Feet Wet" program to provide a low commitment introduction to contesting so that they could see whether or not they liked it."

Jim was instrumental as well in the team organizing what was probably SARC's best scoring Field Day ever. It was in 2015 and, encouraged by Jim, Brett and Stan VA7NF, the Field Day Committee decided that operating QRP might put us in a better scoring position than our usual high power entry.

It took quite a lot of persuasion, but in the end, it was indeed to be QRP. Jim's specialty was consulting propagation predictions and other data to see what we might be able to do with just 5W.  Hoo boy!!  With some adjustment to our antenna lineup, he suggested that we could do very well indeed.

Did we?  We sure did.

Shattered the Canadian record for all categories.

Out of 2,719 FD stations in the US and Canada in 2015, some with more than 10 transmitters and most running 100W, we ranked #91 with our 3 transmitters and 5W.

Altogether a VERY significant achievement which any club would be proud of.

Wouldn't have happened without Jim (or Brett)

The 2015 winning QRP Field Day crew.

It may not be common knowledge that Jim was responsible for a lot of improvements to the premier Amateur Radio Contesting software N1MM+. As an expert contester Jim was able to make suggestions to the programmers that made the software the contesting leader it is today.

Jim always had a liking for analytics, and he took the lead in creating 'Station Manager' training. This role is as important to getting the maximum number of points in a contest as it would be in a real emergency, ensuring that critical traffic got through. The role includes selecting the most useful bands according to shifting propagation, switching antennas, and to assigning operators, so he was constantly monitoring rates, band conditions/solar conditions, greyline, run rates, etc. Everything was graphed and plotted.

Jim was also an active member of ORCA DX and Contest Club, and of the BC DX Club.
As the BC coordinator for the Pacific Northwest Challenge, for many years he looked after the collection of scores for the inter-club contest trophy -- the Pacific Northwest Cup -- and was a frequent attendee at club meetings.

We will miss you, Jim.

Thank you for all that you taught me and others.

We were very fortunate to have had you as a member.

Now Jim is gone

Damn!

Rest in peace.


~ John VE7TI

2021-05-09

A Review of the Hardrock-50 Linear Amplifier Kit

 

Radio Ramblings...

Synopsis

The Hardrock-50 (see Figure 1) is a US-designed, 5W-in to 50W-out HF amplifier that operates on the 160 through 6m amateur bands.  It includes automatic band switching, does not require tuning, and integrates seamlessly with popular rigs such as the Elecraft KX3 or Yaesu FT-817 series.  An optional QSK board and automatic antenna tuner are available.  The amplifier runs on 13.8 VDC and draws under 10 amps at full output. 

The HR-50 is provided as a well-documented kit and can be assembled in about ten hours.  It aligns easily using common test equipment and performs well.  My own kit easily out-performed the amplifier’s design specs.  Price is US$299 from Hobby PCB in Florida at https://hobbypcb.com. 

Background

Having recently returned to amateur radio, I was interested in the new digital modes, and especially the new digital HF mode FT8.  My new Elecraft KX3 performed very well on the mode, and I was able to achieve WAS (Worked All States) in about three weeks using the radio’s maximum recommended digital output of 5 watts into my 23-metre longwire antenna.

That said, working DX using FT8 while QRP was quite difficult, and although I worked a small number of foreign stations, I found that it took quite a bit of effort to be heard among the other stations who were using higher power and better antennas than I have.  I had no problem hearing considerable DX; the problem was that they usually did not hear me.  Something had to be done!

I started researching linear amplifiers with an output of 50 to 100 watts, thinking that being able to boost my signal at the antenna would likely make me more competitive and allow me to work much of the interesting DX that I had been hearing.

I learned that 100-watt class amplifiers were either low quality and affordable, or of high quality, but more expensive than my limited budget would allow.  Reviews of some of the cheap amplifiers showed them to generate high amounts of distortion and even spurious illegal emissions.  Not something that I would allow in my station!

Additionally, I doubted the necessity of running 100 watts on FT8 (my main communication interest) as the mode performs so well on very weak signals that more than 10-30 watts is hardly ever required to work global DX.  50 watts would give me enough “edge” to work a lot of DX.

My extensive research led me to a US-designed amplifier kit called the “Hardrock-50”, from a small firm called “Hobby PCB”1 in the eastern US. The amplifier covers 160 through 10 metres with an output of approximately 50 watts for 5 watts input, and about 40 watts output on 6 metres.

The prototype for the Hardrock-50 was a winner in a design contest sponsored by the ARRL in 2010.  The much-evolved production version, now called the HR-50, is FCC “type accepted” and meets all legal requirements for amateur band operation. 

Reviews of the HR-50 were excellent, and the documentation on the Hobby PCB website showed that the assembly and operation manuals were complete and well-designed, and reminiscent of the classic “Heathkit” manuals of the 1950s-1990s.  It looked like a good solution to my needs.

Purchase

At US$299, the price for the kit met my budget, so in late January I “took the plunge” and ordered the amplifier kit.  I ordered the optional full break-in (QSK) board as a US$30 option, but decided against the internal automatic antenna tuner (a US$179 option) as I already own a nice external auto-tuner from LDG. I planned to use that with the new amplifier.

The kit arrived in a few days.  The parts were all of good quality, and the kit was organized into sub-packs of parts for each main component of the assembly process (front panel; back panel; main PCB, et cetera). 

Assembly

I downloaded the HR-50 assembly manual to my iPad and followed it step-by-step.  The manual is well-written and clear.  There are three PCBs provided: for the front panel, the back panel, and the larger main PCB.  My kit contained a fourth PCB for the optional QSK board.  All the PCBs come pre-populated with the key surface mount components such as the microprocessors which control the amplifier.  The PCBs are manufactured off-shore but quality is good.  No SMD soldering is required.

Assembly starts with the front panel and works through the back panel, the main PCB, and lastly, the QSK board for those customers who have purchased this option.  Assembly consists of inserting and soldering through-hole devices such as the four MOSFET power transistors, band switching relays, connectors, and headers and short jumper cables which link the amplifier’s boards together.

The optional QSK board is installed above the main PCB through provided headers and nylon spacers.  Hardware is of excellent quality (stainless steel) and everything fit together perfectly.

Assembly was straightforward and I encountered only a few issues with the assembly steps.  For example, in one step in assembly of the main PCB, I failed to read the step to the very end, and unfortunately installed two 2-pin terminal blocks which were NOT required if one is installing the QSK board.  I had to de-solder the two terminal blocks as they would mechanically interfere with the QSK board to be installed above.  A minor inconvenience, and technically my error, as I should have read the step to the very end!

An amplifier is an analog device, so the main PCB contains about 15 toroidal inductors which are part of the different ham band filters.  The ~1.5 cm cores and a generous supply of enameled wire are provided. Alternatively, a full set of pre-wound toroids is available as a kit option for US$30.

I chose to wind my own toroids for the experience, as I had never wound smaller toroids such as these.  The directions in the manual were clear and photographs of what the finished toroids should look like are included in the assembly manual, so I decided to do the winding myself.  I thought that it would be a great opportunity to learn a new skill.  See Figure 2 below.


Amplifier filter “Q” (and consequently, amplifier performance) is improved by taking care to wind quality toroids, so it is worth the time to complete these assembly steps properly.  The turns need to be tightly wound and spaced evenly.  Critical is proper counting of the turns through each core. The toroid winding steps took me about two hours.

The hardest part of winding the toroids is removal of the insulation from the wire ends.  This can be accomplished either by scraping (Exacto knife or Dremel tool) or via application of heat from a soldering iron.  I used a combination of the soldering iron method and scraping with an Exacto knife.  This took a couple of hours, but I got it done.  After building the kit, I discovered a great tool for stripping enameled wire3.  It’s designed for this purpose and works really well.  I ordered one for US$14 on Amazon and would definitely recommend using one, as it makes stripping the enameled wire quick and easy!

Three small transformers must also be wound using supplied wire, but these were straightforward once I had completed the big toroid winding job.

The kit includes a large extruded aluminum heatsink to dissipate heat from the four power MOSFETs.  This serves also as the chassis for the entire amplifier.  The main PCB is secured to the heatsink, and the front and back panels are bolted to the ends of the heatsink.  The four MOSFETs and a helpful temperature sensor are also mechanically attached to the heatsink.  The provided aluminum cover then integrates everything into a nice-looking device, as can be seen in the attached photos of my amplifier.

After about ten hours of (fun) work over three days, my amplifier was complete and ready for alignment and testing.  See Figure 3 below.


Alignment

Alignment of the HR-50 requires a 13.8 VDC power supply capable of about 10 amps, a small screwdriver and an ammeter such as available on common DMMs.  The process consists of setting zero-drive bias current on the four MOSFETs. 

This was a straightforward process and my new amplifier tuned up easily and quickly.

Testing

Next came the moment of truth!  I connected the amplifier RF input to my KX3, and the amplifier output to a good quality dummy load.  For the automatic control signals, I connected my KX3’s control output signals and serial port to the amplifier through a small KX3 interface board that I bought from Hobby PCB as a US$30 option. 

I could have made my own (simple) control cable but chose the easy route in this case!  Cable pinouts are provided in the assembly manual for those who want to “roll their own” interface cable.

Three settings on the KX3 had to be changed to set the inter-device baud rate and route PTT to the HR-50.  Similarly, three settings had to be set on the HR-50s control menus.  Then, I was ready to go!

“First Light”

First, I wanted to confirm that the HR-50 was receiving band change information from my KX3.  I reduced my KX3’s output power to 0 watts and cycled up and down through the amateur bands on my KX3.  The HR-50 received the band change data and nicely tracked band changes.

Next came a test of amplifier performance. I keyed the transmitter (still into the dummy load) and increased power to 0.5 watts. The HR-50 was working! I cycled through the bands and noted that power output was working well.  On some bands, for example, I could easily exceed 50 watts output with only 2 to 3 watts of drive.  I was suitably impressed!

On other bands, notably 20 and 80 metres, however, I noted that the HR-50’s output was strangely low.  What could be the cause?

Human Error

I’m as human as the next guy, and this section describes how I resolved this odd “low power on some bands” anomaly.

I investigated the low power situation, particularly on 20 metres, for a few days without resolution.  I suspected that perhaps I had made an error in winding one of the toroids.  I emailed Hobby PCB with a few questions and was honestly surprised when I got an email back from the amplifier’s inventor, Jim Veatch (WA2EUJ) within an hour. 

Jim was very supportive and gave me some suggestions for testing.  He reminded me early that “Hobby PCB guarantees a working amplifier for every customer”, and that if we could not resolve the problem, that I could simply ship my HR-50 to him and that he would personally find the problem and fix it himself.  Impressive customer service! 

I did some troubleshooting using Jim’s suggestions, and the HR-50 seemed to be “normal” in all respects.  Very odd; I pondered this overnight. 

The next morning, I decided to go “back to basics” and troubleshoot from the KX3 outward.  I put a wattmeter on the KX3’s output – something that I had not done before as I was relying on the rig’s internal (more accurate) digital wattmeter. 

I noted that on 20 and 80 metres (the bands with the lowest HR-50 output) that even if I set my KX3 to read 5 watts on its internal wattmeter, that my external meter only read about 1 watt output.  How could this be?  The rig was almost new.  Had I “blown the finals”, as we used to say in the old tube-based rig days? 

Then, a glance at the KX3’s display caused something to “twig”: the KX3’s internal ATU was still on!  The KX3 had previously been used with my non-resonant-on-20-and-80 longwire antenna and still assumed that it was feeding that antenna, not the amplifier.  The rig was now connected to the (resonant) HR-50.  Eureka!

I disabled the KX3’s ATU, and the external wattmeter now showed 5 watts output on each band.  The HR-50’s output into the dummy load jumped to what it should be, 50 watts+ on 160 through 10, and 40 – 50 watts on 6 metres.  I was in business!  See Figure 4 below.


Performance

I hit the bands with my longwire and noted vastly improved reception of my signal by both NA and DX stations.  The option to run up to 50 watts is great and has allowed me to make many more contacts that I could with 3 (maximum 5) watts digital on my “barefoot” KX3.

Now, about three weeks in, the HR-50 continues to perform perfectly.  The front panel user interface is easy to use, and the amplifier tracks band changes automatically. 

Also appreciated is the fact that the amplifier is unaffected by high SWR at the antenna connector.  An open circuit, or even a dead short at the antenna terminal will not damage the MOSFETs.  Of course, I have not made either of these errors, but it is nice to know that the finals cannot be “blown”, like in the “olden days”!

The heatsink gets quite hot using digital modes like FT8 with its 50-percent duty cycle, and heatsink temperature can reach 50 to 60 degrees Celsius.  However, these heatsink temperatures are within the amplifier’s “normal” range, and the HR-50 operating manual says that external cooling should only be considered if the heatsink temperature goes above 90 degrees C.  This is unlikely, in my experience.

The QSK board in the amplifier also works well and provides silent and extremely fast T/R switching, including “inter-dit” reception when using CW.

Conclusion

For my station and operating profile, the Hardrock-50 was a great investment.  The kit is professionally designed and well documented, the amplifier works as specified, and it is backed by excellent support.  Assembly was straightforward and fun, and I learned something about winding toroids.  I will also not forget to turn off my KX3’s ATU when I return from portable to base operation!

I am extremely happy with the HR-50 kit and would highly recommend it to anyone running QRP and looking for a moderate boost in output power. 

That’s it for this review.  Please feel free to send comments and questions to me at mcquiggi@sfu.ca. 

~ Kevin VE7ZD/K7MCQ

   19-03


2017-11-16

A 6m Loop Antenna


A Communicator Reprise: July 2010

For the original article:  http://tinyurl.com/SARC10-07


This weekend project is inexpensive,  yields  good  SWR  and works well with an auto tuner. Tune it  for  50.125  and  enjoy  some  DX Fun.

Six metres has some interesting openings.  Sunday evening I worked W7RN in Virginia City Nevada with a crystal clear 59+  signal on USB… was my first DM09 grid square on six metres.  My antenna, a simple horizontally polarized ½Î» dipole made with ½” aluminum tubing mounted low on the side of my roof.  I was delighted to say the least.  AND my 6 metre J-pole turns out to work wonderfully on the 10 metre band and I was able to take a New Caledonia QSO this weekend as well.  Ham heaven for those of us not running a lot of power or fancy multi-element antennas on 70 foot towers.  All my antennas barely clear the peak of the roof, and I am amazed every time I make a DX contact.

So,  if you wanted to get on 6m and don’t have  room for, or the permission to install, a  large multi element antenna, here is one that will – when conditions are right – allow you to get on 6 and experience the “magic band.”

The  antenna  is  not  hard  to  build  [assuming  basic  metalworking  tools]  and  takes  basically  one  piece  of aluminum plate and one aluminum ‘strap’ which you can find at Metal Supermarket, ABC Traders or MetalMart, and one 1” dia. piece of ABS or PVC tubing with caps, a SO-239 and 17” of #12 solid copper wire.  The strap is slotted  to  allow  major  tuning  for what 500 KHz of bandwidth you want to work.  It’s a loop, so its hi-Q and thus narrow band. But it’s small(ish) and works horizontally or vertically.





If these are too small, open the original http://tinyurl.com/SARC10-07







CQ CQ CQ

Five-band HF Linked Dipole [updated January 2025]

An improved build This antenna was first described in the November-December 2023 Communicator. After a year of using it, I’ve developed som...

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